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Sample records for chemical coating

  1. Combustion chemical vapor desposited coatings for thermal barrier coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Hampikian, J.M.; Carter, W.B. [Georgia Institute of Technology, Atlanta, GA (United States)

    1995-10-01

    The new deposition process, combustion chemical vapor deposition, shows a great deal of promise in the area of thermal barrier coating systems. This technique produces dense, adherent coatings, and does not require a reaction chamber. Coatings can therefore be applied in the open atmosphere. The process is potentially suitable for producing high quality CVD coatings for use as interlayers between the bond coat and thermal barrier coating, and/or as overlayers, on top of thermal barrier coatings.

  2. Combustion chemical vapor deposited coatings for thermal barrier coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Hampikian, J.M.; Carter, W.B. [Georgia Institute of Technology, Atlanta, GA (United States). School of Materials Science and Engineering

    1995-12-31

    The new deposition process, combustion chemical vapor deposition, shows a great deal of promise in the area of thermal barrier coating systems. This technique produces dense, adherent coatings, and does not require a reaction chamber. Coatings can therefore be applied in the open atmosphere. The process is potentially suitable for producing high quality CVD coatings for use as interlayers between the bond coat and thermal barrier coating, and/or as overlayers, on top of thermal barrier coatings. In this report, the evaluation of alumina and ceria coatings on a nickel-chromium alloy is described.

  3. Chemical vapor deposition coating for micromachines

    Energy Technology Data Exchange (ETDEWEB)

    MANI,SEETHAMBAL S.; FLEMING,JAMES G.; SNIEGOWSKI,JEFFRY J.; DE BOER,MAARTEN P.; IRWIN,LAWRENCE W.; WALRAVEN,JEREMY A.; TANNER,DANELLE M.; DUGGER,MICHAEL T.

    2000-04-21

    Two major problems associated with Si-based MEMS devices are stiction and wear. Surface modifications are needed to reduce both adhesion and friction in micromechanical structures to solve these problems. In this paper, the authors will present a process used to selectively coat MEMS devices with tungsten using a CVD (Chemical Vapor Deposition) process. The selective W deposition process results in a very conformal coating and can potentially solve both stiction and wear problems confronting MEMS processing. The selective deposition of tungsten is accomplished through silicon reduction of WF{sub 6}, which results in a self-limiting reaction. The selective deposition of W only on polysilicon surfaces prevents electrical shorts. Further, the self-limiting nature of this selective W deposition process ensures the consistency necessary for process control. Selective tungsten is deposited after the removal of the sacrificial oxides to minimize process integration problems. This tungsten coating adheres well and is hard and conducting, requirements for device performance. Furthermore, since the deposited tungsten infiltrates under adhered silicon parts and the volume of W deposited is less than the amount of Si consumed, it appears to be possible to release stuck parts that are contacted over small areas such as dimples. Results from tungsten deposition on MEMS structures with dimples will be presented. The effect of wet and vapor phase cleanings prior to the deposition will be discussed along with other process details. The W coating improved wear by orders of magnitude compared to uncoated parts. Tungsten CVD is used in the integrated-circuit industry, which makes this approach manufacturable.

  4. Boron coating on boron nitride coated nuclear fuels by chemical vapor deposition

    Science.gov (United States)

    Durmazuçar, Hasan H.; Gündüz, Güngör

    2000-12-01

    Uranium dioxide-only and uranium dioxide-gadolinium oxide (5% and 10%) ceramic nuclear fuel pellets which were already coated with boron nitride were coated with thin boron layer by chemical vapor deposition to increase the burn-up efficiency of the fuel during reactor operation. Coating was accomplished from the reaction of boron trichloride with hydrogen at 1250 K in a tube furnace, and then sintering at 1400 and 1525 K. The deposited boron was identified by infrared spectrum. The morphology of the coating was studied by using scanning electron microscope. The plate, grainy and string (fiber)-like boron structures were observed.

  5. Coatings.

    Science.gov (United States)

    Anderson, Dennis G.

    1989-01-01

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

  6. Surface modification of silica-coated zirconia by chemical treatments

    Energy Technology Data Exchange (ETDEWEB)

    Lung, Christie Ying Kei, E-mail: yklung@graduate.hku.hk [Dental Materials Science, Faculty of Dentistry, University of Hong Kong (Hong Kong); Kukk, Edwin, E-mail: ekukk@utu.fi [Department of Physics and Astronomy, Faculty of Mathematics and Natural Sciences, University of Turku (Finland); Haegerth, Toni, E-mail: tjhage@utu.fi [Department of Physics and Astronomy, Faculty of Mathematics and Natural Sciences, University of Turku (Finland); Matinlinna, Jukka Pekka, E-mail: jpmat@hku.hk [Dental Materials Science, Faculty of Dentistry, University of Hong Kong (Hong Kong)

    2010-12-01

    Zirconia surface modification by various chemical treatments after silica coating by sandblasting was investigated in this study. The surface of silica-coated dental zirconia was hydroxylated by treatment with different acids at room temperature for 4 h, rinsed with deionized water and air-dried. The modified surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Shifts in binding energies for Zr 3d{sub 5/2} and Si 2p peaks were observed after treatment with acids, thereby showing a change in the chemical states of zirconium and silicon on the surface layer of silica-coated zirconia. The XPS analysis revealed that the silica-coated zirconia (SiO{sub 2}-ZrO{sub 2}) surfaces had changed to hydrous silica-coated zirconia (SiO{sub 2}-ZrO{sub 2}.nH{sub 2}O). One-way ANOVA analysis revealed there was significant difference in both surface roughness parameters of silica-coated zirconia after chemical treatments and the surface topography varied depending on the acid treatment.

  7. Chemical vapor deposited fiber coatings and chemical vapor infiltrated ceramic matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Kmetz, M.A.

    1992-01-01

    Conventional Chemical Vapor Deposition (CVD) and Organometallic Chemical Vapor Deposition (MOCVD) were employed to deposit a series of interfacial coatings on SiC and carbon yarn. Molybdenum, tungsten and chromium hexacarbonyls were utilized as precursors in a low temperature (350[degrees]C) MOCVD process to coat SiC yarn with Mo, W and Cr oxycarbides. Annealing studies performed on the MoOC and WOC coated SiC yarns in N[sub 2] to 1,000[degrees]C establish that further decomposition of the oxycarbides occurred, culminating in the formation of the metals. These metals were then found to react with Si to form Mo and W disilicide coatings. In the Cr system, heating in N[sub 2] above 800[degrees]C resulted in the formation of a mixture of carbides and oxides. Convention CVD was also employed to coat SiC and carbon yarn with C, Bn and a new interface designated BC (a carbon-boron alloy). The coated tows were then infiltrated with SiC, TiO[sub 2], SiO[sub 2] and B[sub 4]C by a chemical vapor infiltration process. The B-C coatings were found to provide advantageous interfacial properties over carbon and BN coatings in several different composite systems. The effectiveness of these different coatings to act as a chemically inert barrier layer and their relationship to the degree of interfacial debonding on the mechanical properties of the composites were examined. The effects of thermal stability and strength of the coated fibers and composites were also determined for several difference atmospheres. In addition, a new method for determining the tensile strength of the as-received and coated yarns was also developed. The coated fibers and composites were further characterized by AES, SEM, XPS, IR and X-ray diffraction analysis.

  8. Chemical vapor deposition coatings for oxidation protection of titanium alloys

    Science.gov (United States)

    Cunnington, G. R.; Robinson, J. C.; Clark, R. K.

    1991-01-01

    Results of an experimental investigation of the oxidation protection afforded to Ti-14Al-21Nb and Ti-14Al-23Nb-2V titanium aluminides and Ti-17Mo-3Al-3Nb titanium alloy by aluminum-boron-silicon and boron-silicon coatings are presented. These coatings are applied by a combination of physical vapor deposition (PVD) and chemical vapor deposition (CVD) processes. The former is for the application of aluminum, and the latter is for codeposition of boron and silicon. Coating thickness is in the range of 2 to 7 microns, and coating weights are 0.6 to 2.0 mg/sq cm. Oxidation testing was performed in air at temperatures to 1255 K in both static and hypersonic flow environments. The degree of oxidation protection provided by the coatings is determined from weight change measurements made during the testing and post test compositional analyses. Temperature-dependent total normal emittance data are also presented for four coating/substrate combinations. Both types of coatings provided excellent oxidation protection for the exposure conditions of this investigation. Total normal emittances were greater than 0.80 in all cases.

  9. Akzo Nobel Strengthens Presence in Coatings and Chemicals Businesses

    Institute of Scientific and Technical Information of China (English)

    Lily Wang

    2007-01-01

    @@ Over the last few years, Akzo Nobel has been very active in China. Akzo Nobel announced a Euro 250 million investment for a new chemicals multisite in Ningbo,and the company has also opened new coatings facilities in Suzhou, Langfang,Tianjin and Jiaxing, bringing the total number ofplants to 22 and the number of employees to almost 5000.

  10. An electrothermal chemical technology for thermal spray coatings

    International Nuclear Information System (INIS)

    A new spray technology for producing hard-coatings, has been developed at the SOREQ Nuclear Research Center. The concept is based on the extensive experience accumulated at SOREQ in the course of the development of Electrothermal (ET), Electrothermal-Chemical (ETC) and Solid-Propellant Electrothermal-Chemical (SPETC) guns(r). High quality coatings may be obtained by thermal spraying powder particles onto a variety of substrates. Mature state-of-the-art technologies such as plasma spray, high velocity oxy fuel (HVOF) and detonation gun (D-Gun) are widely used for many applications. As each method has its own drawbacks there is a need for a combination of several parameters which cannot be achieved by any existing individual commercial technology. The method presented is oriented toward a high-quality, multi-step, high-throughput, easily programmable continuous coating process and relatively inexpensive technology. The combustion products of a solid or liquid propellant accelerate the powder particles of the coating material. A pulsed-plasma jet, provided by a confined capillary discharge, ignites the propellant and controls the combustion process. The powder particles are accelerated to velocities over 1000 m/s. Due to the very high carrier gas density, high velocity, high throughput and high powder consumption efficiency are obtained. The plasma jet enables control of the gas temperature and consequently influences the powder temperature

  11. Synthesis of mullite coatings by chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Mulpuri, R.P.; Auger, M.; Sarin, V.K. [Boston Univ., MA (United States)

    1996-08-01

    Formation of mullite on ceramic substrates via chemical vapor deposition was investigated. Mullite is a solid solution of Al{sub 2}O{sub 3} and SiO{sub 2} with a composition of 3Al{sub 2}O{sub 3}{circ}2SiO{sub 2}. Thermodynamic calculations performed on the AlCl{sub 3}-SiCl{sub 4}-CO{sub 2}-H{sub 2} system were used to construct equilibrium CVD phase diagrams. With the aid of these diagrams and consideration of kinetic rate limiting factors, initial process parameters were determined. Through process optimization, crystalline CVD mullite coatings have been successfully grown on SiC and Si{sub 3}N{sub 4} substrates. Results from the thermodynamic analysis, process optimization, and effect of various process parameters on deposition rate and coating morphology are discussed.

  12. Coating of metals with titanium diboride by chemical vapor deposition

    International Nuclear Information System (INIS)

    This study is an experimental investigation of the chemical vapor deposition of titanium diboride on metallic substrates by the hydrogen reduction of TiCl4 and BCl3 at temperatures between 8500C and 11000C. Kovar, tantalum, and several stainless steels were found to be suitable substrates since they could withstand the deposition temperature, had adequate resistance to HCl, a by-product of the deposition reaction, and had thermal expansion coefficients sufficiently close to that of TiB2 (less than or equal to10 x 10-6/0C). The TiB2 coatings produced were 68.2% Ti and thus near stoichiometry and had very low impurity content. They had Knoop hardnesses averaging 3300 kg/mm2 and exhibited extraordinary erosion resistance

  13. A Study on Medium Temperature Chemical Vapor Deposition (MT-CVD) Technology and Super Coating Materials

    Institute of Scientific and Technical Information of China (English)

    GAO Jian; LI Jian-ping; ZENG Xiang-cai; MA Wen-cun

    2004-01-01

    In this paper, the dense and columnar crystalline TiCN coating layers with very good bonding strength between a layer and another layer was deposited using Medium Temperature Chemical Vapor Deposition (MT-CVD) where CH3CN organic composite with C/N atomic clusters etc. was utilized at 700 ~ 900 ℃. Effect of coating processing parameters, such as coating temperature, pressure and different gas flow quantity on structures and properties of TiCN coating layers were investigated. The super coating mechanis mand structures were analyzed. The new coating processing parameters and properties of carbide inserts with super coating layers were gained by using the improved high temperature chemical vapor deposition (HTCVD) equipment and HT-CVD, in combination with MT-CVD technology.

  14. Surface characteristics of chemical conversion coating for Mg-Al alloy

    Institute of Scientific and Technical Information of China (English)

    Masazumi OKIDO; Ryoichi ICHINO; Seong-Jong KIM; Seok-Ki JANG

    2009-01-01

    The chemical conversion coating was formed on Mg alloy for low cost and harmlessness in environment by using the colloidal silica as the main component. The film formed at 298 K was thick, which was thought to be the combination of Si and O. In salt spray test, the ratio of black rust on the specimen that did not conducted chemical conversion treatment was five times or more than those of the chemical conversion treated specimen. The film of chemical conversion coating produced by alkali treatment process was thinner than the specimen produced in basic chemical conversion treatment solution.

  15. Corrosion resistance, composition and structure of RE chemical conversion coating on magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Golden yellow rare earths chemical conversion coating was obtained on the surface of magnesium alloy by immersing in cerium sulfate solution.The corrosion resistance of RE conversion coating was evaluated using immersion test and potentiodynamic polarization measurements in 3.5%NaCl solution.The morphologies of samples before corrosion and after corrosion were observed by SEM.The structures and compositions of the RE conversion coating were studied by means of XPS.XRD and IR.The results show that,the conversion coating consists of mainly two kinds of element Ce and O,the valences of cerium are+3 and+4.and OH exists in the coating.The anti-corrosion property of magnesium alloy is increased obviously by rare earths conversion coating,Its self-corrosion current density decreases and the coating has self-repairing capability in the corrosion process in 3.5%NaCl solution.

  16. Mechanical properties of chemical vapor deposited coatings for fusion reactor application

    International Nuclear Information System (INIS)

    Chemical vapor deposited coatings of TiB2, TiC and boron on graphite substrates are being developed for application as limiter materials in magnetic confinement fusion reactors. In this application severe thermal shock conditions exist and to do effective thermo-mechanical modelling of the material response it is necessary to acquire elastic moduli, fracture strength and strain to fracture data for the coatings. Four point flexure tests have been conducted from room temperature to 20000C on TiB2 and boron coated graphite with coatings in tension and compression and the mechanical properties extracted from the load-deflection data. In addition, stress relaxation tests from 500 to 11500C were performed on TiB2 and TiC coated graphite beams to assess the low levels of plastic deformation which occur in these coatings. Significant differences have been observed between the effective mechanical properties of the coatings and literature values of the bulk properties

  17. Quantification of simultaneous solvent evaporation and chemical curing in thermoset coatings

    DEFF Research Database (Denmark)

    Kiil, Søren

    2010-01-01

    The mechanisms of simultaneous solvent evaporation and film formation in high-solids thermoset coatings are considered. The relevant phenomena, chemical reactions, solvent diffusion and evaporation, gelation, vitrification, network mobility restrictions, and crosslinking, are quantified...

  18. Evaluation of chemical and structural properties of germanium-carbon coatings deposited by plasma enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Jamali, Hossein, E-mail: h.jamali@mut-es.ac.ir; Mozafarinia, Reza; Eshaghi, Akbar

    2015-10-15

    Germanium-carbon coatings were deposited on silicon and glass substrates by plasma enhanced chemical vapor deposition (PECVD) using three different flow ratios of GeH{sub 4} and CH{sub 4} precursors. Elemental analysis, structural evaluation and microscopic investigation of coatings were performed using laser-induced breakdown spectroscopy (LIBS), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM), respectively. Based on the results, the coatings exhibited a homogeneous and dense structure free of pores with a very good adhesion to substrate. The structural evaluation revealed that the germanium-carbon coatings were a kind of a Ge-rich composite material containing the amorphous and crystalline germanium and amorphous carbon with the mixture of Ge–Ge, Ge–C, C–C, Ge–H and C–H bonds. The result suggested that the amorphisation of the coatings could be increased with raising CH{sub 4}:GeH{sub 4} flow rate ratio and subsequently increasing C amount incorporated into the coating. - Highlights: • Germanium-carbon coatings were prepared by PECVD technique. • The germanium-carbon coatings were a kind of composite material. • The amorphisation of the coatings were increased with raising CH{sub 4}:GeH{sub 4} flow ratio.

  19. Microstructural characterization and chemical compatibility of pulsed laser deposited yttria coatings on high density graphite

    International Nuclear Information System (INIS)

    Yttria coatings were deposited on high density (HD) graphite substrate by pulsed laser deposition method and subsequently annealing in vacuum at 1373 K was carried out to evaluate the thermal stability of the coatings. Yttria deposited on HD graphite samples were exposed to molten LiCl–KCl salt at 873 K for 3 h to evaluate the corrosion behavior of the coating for the purpose of pyrochemical reprocessing applications. The microstructure and the corrosion behavior of the yttria coating deposited on HD graphite in molten LiCl–KCl salt were evaluated by several characterization techniques. X-ray diffraction and Laser Raman patterns confirmed the presence of cubic phase of yttria in the coating. The surface morphology of yttria coating on HD graphite examined by scanning electron microscope and atomic force microscopy revealed the agglomeration of oxide particles and formation of clusters. After annealing at 1373 K, no appreciable grain growth of yttria particles could be observed. X-ray photoelectron spectroscopy analysis was carried out for elemental analysis before and after chemical compatibility test of the coated samples in molten LiCl–KCl salt to identify the corrosive elements present on the yttria coatings. The chemical compatibility and thermal stability of the yttria coating on HD graphite in molten LiCl–KCl salt medium have been established. - Highlights: • Y2O3 coating was deposited on graphite by pulsed laser deposition method. • Chemical compatibility of Y2O3 coating in LiCl–KCl salt at 873 K was studied. • Gibbs free energy change was positive for Y2O3 reaction with Cl2, U and UCl3. • Y2O3 coating exhibited better corrosion performance in molten LiCl–KCl salt

  20. Microstructural characterization and chemical compatibility of pulsed laser deposited yttria coatings on high density graphite

    Energy Technology Data Exchange (ETDEWEB)

    Sure, Jagadeesh [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam — 603 102 (India); Mishra, Maneesha [Physical Metallurgy Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102 (India); Tarini, M. [SRM University, Kattankulathur-603 203 (India); Shankar, A. Ravi; Krishna, Nanda Gopala [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam — 603 102 (India); Kuppusami, P. [Physical Metallurgy Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102 (India); Mallika, C. [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam — 603 102 (India); Mudali, U. Kamachi, E-mail: kamachi@igcar.gov.in [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam — 603 102 (India)

    2013-10-01

    Yttria coatings were deposited on high density (HD) graphite substrate by pulsed laser deposition method and subsequently annealing in vacuum at 1373 K was carried out to evaluate the thermal stability of the coatings. Yttria deposited on HD graphite samples were exposed to molten LiCl–KCl salt at 873 K for 3 h to evaluate the corrosion behavior of the coating for the purpose of pyrochemical reprocessing applications. The microstructure and the corrosion behavior of the yttria coating deposited on HD graphite in molten LiCl–KCl salt were evaluated by several characterization techniques. X-ray diffraction and Laser Raman patterns confirmed the presence of cubic phase of yttria in the coating. The surface morphology of yttria coating on HD graphite examined by scanning electron microscope and atomic force microscopy revealed the agglomeration of oxide particles and formation of clusters. After annealing at 1373 K, no appreciable grain growth of yttria particles could be observed. X-ray photoelectron spectroscopy analysis was carried out for elemental analysis before and after chemical compatibility test of the coated samples in molten LiCl–KCl salt to identify the corrosive elements present on the yttria coatings. The chemical compatibility and thermal stability of the yttria coating on HD graphite in molten LiCl–KCl salt medium have been established. - Highlights: • Y{sub 2}O{sub 3} coating was deposited on graphite by pulsed laser deposition method. • Chemical compatibility of Y{sub 2}O{sub 3} coating in LiCl–KCl salt at 873 K was studied. • Gibbs free energy change was positive for Y{sub 2}O{sub 3} reaction with Cl{sub 2}, U and UCl{sub 3}. • Y{sub 2}O{sub 3} coating exhibited better corrosion performance in molten LiCl–KCl salt.

  1. Chemical conversion coating for protecting magnesium alloys from corrosion

    Science.gov (United States)

    Bhargava, Gaurang; Allen, Fred M.; Skandan, Ganesh; Hornish, Peter; Jain, Mohit

    2016-01-05

    A chromate-free, self-healing conversion coating solution for magnesium alloy substrates, composed of 10-20 wt. % Mg(NO.sub.3).sub.2.6H.sub.2O, 1-5 wt. % Al(NO.sub.3).sub.3.9H.sub.2O, and less than 1 wt. % of [V.sub.10O.sub.28].sup.6- or VO.sub.3.sup.- dissolved in water. The corrosion resistance offered by the resulting coating is in several hundreds of hours in salt-spray testing. This prolonged corrosion protection is attributed to the creation of a unique structure and morphology of the conversion coating that serves as a barrier coating with self-healing properties. Hydroxoaluminates form the backbone of the barrier protection offered while the magnesium hydroxide domains facilitate the "slow release" of vanadium compounds as self-healing moieties to defect sites, thus providing active corrosion protection.

  2. Direct imaging of mechanical and chemical gradients across the thickness of graded organosilicone microwave PECVD coatings.

    Science.gov (United States)

    Hall, Colin J; Murphy, Peter J; Griesser, Hans J

    2014-01-22

    The characterization of variations in the chemical composition and ensuing mechanical properties across the thickness of coatings with continuously varying compositions through their thickness (graded coatings) presents considerable challenges for current analytical techniques in materials science. We report here the direct imaging of nanomechanical and chemical gradients across cross-sections of an organosilicone coating fabricated via microwave plasma enhanced chemical vapor deposition (PECVD). Cross-sectional nanoindentation was used to determine the mechanical properties of uniform and graded organosilicone coatings. Both hardness and modulus across the coatings were directly measured. Additionally, "modulus mapping" on cross-sections was used to map the complex modulus. For the graded coating, it was found that variations in the complex modulus was predominantly due to varying storage modulus. It was observed that at the interface with the substrate there was a low storage modulus, which linearly increased to a relatively high storage modulus at the surface. It is proposed that the increase in stiffness, from the substrate interface to the outer surface, is due to the increasing content of a cross-linked O-Si-O network. This mechanical gradient has been linked to a change in the Si:O ratio via direct compositional mapping using ToF-SIMS. Direct mapping of the mechanical and compositional gradients across these protective coatings provides insight into the changes in properties with depth and supports optimization of the critical mechanical performance of PECVD graded coatings.

  3. Elaboration of composite and chemically heterogeneous icephobic coatings

    Science.gov (United States)

    Arianpour, Faranak

    Atmospheric icing happens when the surfaces of exposed structures are subjected to contact with super-cooled water droplets or snow particles. Ice build-up on overhead transmission and distribution lines may lead to mechanical failure or insulator flashover, sometimes resulting in power outages with major socioeconomic consequences. The present study focused on the preparation of heterogeneous coatings (HCs) with hydro- and icephobic properties presenting a number of advantages, such as easy application, time-saving and low cost. The homo- and HCs were prepared by using different methods such as self-assembly, nanoparticles-based and Plasma-based techniques. Super-hydrophobic coatings with very low wetting hysteresis are also considered to be icephobic. However, even super-hydrophobic coatings can deteriorate during successive icing/de-icing cycles, and this can lead to ice mechanical anchoring since liquid water penetrates the porous surface. Additionally, the cost and complexity involved in the fabrication of such coatings as micro and nano roughness is created, constitute other hurdles. In this study HCs are considered as a coating including hydrocarbons and fluorocarbons, while purely hydrocarbons or fluorocarbons coatings are considered as the homogeneous coatings. It was shown by applying different functions (both C-F and C-H) the surface energy is decreased more compared to applying only one function (C-F or C-H alone). It should be noted that the water molecule orientations at the surfaces of the fluorocarbon and hydrocarbon groups were completely different. As a result, by inducing or creating various disparities (hydrocarbons and fluorocarbons) in terms of energy bonding, and water molecule orientation at the molecular level, the ice-solid interface is weakened. The wettability measurement of the HCs showed higher water contact angle (CA) values and smaller water contact angle hysteresis (CAH) values compared to homogeneous coatings. The most important

  4. Mechanical and microstructural/chemical degradation of coating and substrate in gas turbine blade

    Energy Technology Data Exchange (ETDEWEB)

    Sugita, Y.; Ito, M. [Chubu Electric Power Co. Inc., Nagoya (Japan); Sakurai, S. [Hitachi Ltd., Ibaraki (Japan). Hitachi Research Lab.; Gold, C.R.; Bloomer, T.E.; Kameda, J. [Iowa State Univ. of Science and Technology, Ames, IA (United States). Center for Advanced Technology Development

    1995-12-31

    The mechanical property degradation (295--1223 K) and microstructural/chemical evolution of CoNiCrAlY coatings and superalloy (Rene 80) substrates in gas turbine blades operated in- service have been studied using a small punch (SP) testing technique and scanning Auger microprobe. In SP tests, coating cracks continuously and discretely propagated at 295 K and higher temperatures, respectively. The ductile-brittle transition temperature of the coatings was increased during long time exposure of gas turbine blades to oxidizing environments while that of the substrate did not change. The low cycle fatigue life of the coatings at 295 K was also reduced in-service. Oxidation and sulfur segregation near the coating surface were found to be major causes of the mechanical degradation of the coatings.

  5. Preparation and properties of nano-composite ceramic coating by thermo chemical reaction method

    Institute of Scientific and Technical Information of China (English)

    MA Zhuang; SUN Fang-hong; LI Zhi-chao

    2007-01-01

    Nano-composite ceramic coating was fabricated on Q235 steel through thermo chemical reaction method. Structure of the coating was analyzed and the properties were tested. The results show that a few of new ceramic phases, such as MgAl2O4, ZnAl2O4,Al2SiO5, Ni3Fe and Fe3Al, are formed on the coating during the process of solidifying at 600 ℃. The ceramic coating is dense and the high bonding strength is obtained. The average bonding strength between the coating and matrix could be 14.22 MPa. The acid resistance of the coating increase by 8.8 times, the alkali resistance by 4.1 times, the salt resistance by 10.3 times, and the wear resistance by 2.39 times.

  6. Chemicals: UV-curable coating for aluminum can production

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-09-29

    Fact sheet on curing aluminum can coatings written for the NICE3 Program. Coors Brewing Company has been using ultraviolet (UV) light curing technology on its aluminum beverage cans for 25 years. The company is now looking to share its cost-saving technology with other aluminum can producers. Traditional curing methods for creating external decorations on cans rely on convective-heat ovens to cure ink and over-varnish coatings. These thermal-curing methods require large amounts of energy and money, and can have unintended environmental impacts. Coors' technique uses coating materials that cure when exposed to UV light, thereby eliminating the expensive heat treatments used by conventional coating methods. Additionally, the UV-coating process creates much lower emissions and a smaller pollution waste stream than rival thermal processes because it requires much less solvent than thermal processes. This technology can be used not only in the aluminum can industry, but in the automotive, airline, wood, paper, and plastics industries, as well.

  7. Chemical reactivity of PVD-coated WC-Co tools with steel

    Energy Technology Data Exchange (ETDEWEB)

    Gimenez, S. [Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 44, B-3001 Heverlee (Belgium); Huang, S.G. [Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 44, B-3001 Heverlee (Belgium); Van der Biest, O. [Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 44, B-3001 Heverlee (Belgium); Vleugels, J. [Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 44, B-3001 Heverlee (Belgium)]. E-mail: jozef.vleugels@mtm.kuleuven.be

    2007-01-30

    The chemical reactivity of CrN, ZrN, TiC {sub x}N{sub 1-x} and naCo (registered) PVD coatings on a WC-Co cemented carbide substrate with steel has been evaluated by means of the static interaction couples technique. Diffusion experiments with coated and uncoated tools were carried out at 900, 1100 and 1300 deg. C in order to establish the maximum temperature at which the substrate-coating-workpiece combinations are chemically stable. Computational equilibrium thermodynamics was used to identify the interaction products formed at elevated temperature and the chemical solubility of the different coating materials into iron. A metallic (Fe, Co) fcc solid solution was identified at the steel side of the interface from 1100 deg. C on for all the coated tools and from 900 deg. C for the uncoated carbide. In addition to this interaction product, the {eta}-carbide was identified at 1300 deg. C on the WC-Co side of the interface. Both of the experimental findings and thermodynamic equilibrium solubility calculations demonstrated that the PVD-coated WC-Co tools exhibit a lower chemical reactivity with respect to the uncoated tools.

  8. Chemical reactivity of PVD-coated WC-Co tools with steel

    International Nuclear Information System (INIS)

    The chemical reactivity of CrN, ZrN, TiC xN1-x and naCo (registered) PVD coatings on a WC-Co cemented carbide substrate with steel has been evaluated by means of the static interaction couples technique. Diffusion experiments with coated and uncoated tools were carried out at 900, 1100 and 1300 deg. C in order to establish the maximum temperature at which the substrate-coating-workpiece combinations are chemically stable. Computational equilibrium thermodynamics was used to identify the interaction products formed at elevated temperature and the chemical solubility of the different coating materials into iron. A metallic (Fe, Co) fcc solid solution was identified at the steel side of the interface from 1100 deg. C on for all the coated tools and from 900 deg. C for the uncoated carbide. In addition to this interaction product, the η-carbide was identified at 1300 deg. C on the WC-Co side of the interface. Both of the experimental findings and thermodynamic equilibrium solubility calculations demonstrated that the PVD-coated WC-Co tools exhibit a lower chemical reactivity with respect to the uncoated tools

  9. PARTICLE COATING BY CHEMICAL VAPOR DEPOSITION IN A FLUIDI7ED BED REACTOR

    Institute of Scientific and Technical Information of China (English)

    Gregor; Czok; Joachim; Werther

    2005-01-01

    Aluminum coatings were created onto glass beads by chemical vapor deposition in a fluidized bed reactor at different temperatures. Nitrogen was enriched with Triisobutylaluminum (TIBA) vapor and the latter was thermally decomposed inside the fluidized bed to deposit the elemental aluminum. To ensure homogeneous coating on the bed material, the fluidizing conditions necessary to avoid agglomeration were investigated for a broad range of temperatures.The deposition reaction was modeled on the basis of a discrete particle simulation to gain insight into homogeneity and thickness of the coating throughout the bed material. In particular, the take-up of aluminum was traced for selected particles that exhibited a large mass of deposited aluminum.

  10. Chemical sensors using coated or doped carbon nanotube networks

    Science.gov (United States)

    Li, Jing (Inventor); Meyyappan, Meyya (Inventor)

    2010-01-01

    Methods for using modified single wall carbon nanotubes ("SWCNTs") to detect presence and/or concentration of a gas component, such as a halogen (e.g., Cl.sub.2), hydrogen halides (e.g., HCl), a hydrocarbon (e.g., C.sub.nH.sub.2n+2), an alcohol, an aldehyde or a ketone, to which an unmodified SWCNT is substantially non-reactive. In a first embodiment, a connected network of SWCNTs is coated with a selected polymer, such as chlorosulfonated polyethylene, hydroxypropyl cellulose, polystyrene and/or polyvinylalcohol, and change in an electrical parameter or response value (e.g., conductance, current, voltage difference or resistance) of the coated versus uncoated SWCNT networks is analyzed. In a second embodiment, the network is doped with a transition element, such as Pd, Pt, Rh, Ir, Ru, Os and/or Au, and change in an electrical parameter value is again analyzed. The parameter change value depends monotonically, not necessarily linearly, upon concentration of the gas component. Two general algorithms are presented for estimating concentration value(s), or upper or lower concentration bounds on such values, from measured differences of response values.

  11. Characteristic comparison of metal films coated onto the cenosphere by chemical and magnetron sputtering methods

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Metal-coated cenospheres have been widely used in Industries. Different coating methods result in different characteristic metal films. Hie metal film on the cenosphere by chemical coating does not appear to be very smooth, exhibiting metal piled up and pin holes on the surface and leaving some spots uncoated. Meanwhile, the metal film is not tightly absorbed onto cenospheres and is easy to peel off. However, the metal film prepared by magnetron sputtering is compact, smooth and without pin holes. The film has good affinity to the cenosphere surface. Such films do not separate with it even when the cenosphere is crushed. Both the metal films give the same XRD patterns, indicating tnat the crystal structure of the metal films by these two methods is the same. Chemical coating is a complex process and harmful to the environment, but it fits ultrafine powder coating (the particle size can be less than 2 μm). The magnetron sputtering method is environmental friendly and works quickly, but this method requires specially designed equipment and does not work for ultrafine powders. If the particle size is less than 30 μm, the coating process is hard to carry on.

  12. [Chemical constituents from the seed coat of Juglans regia].

    Science.gov (United States)

    Liu, Chuanshui; Tai, Zhigang; Feng, Siquan; Fang, Yunshan; Cai, Le; Ding, Zhongtao

    2012-05-01

    Fifteen compounds were isolated from the seed coat of Juglans regia by silica gel, MCI gel and Sephadex LH-20 gel column chromatography, as well as high preparative performance liquid chromatography. Their structures were identified as salidroside (1), (6S, 9S)-roseoside (2), (6S, 9R)-roseoside (3), blumenol C glucoside (4), byzantionoside B (5), 5-hydroxy-2-methoxy-1, 4-naphthoquinone (6), gallic acid (7), glycerol 1-(9Z-octadecenoate)-2-(9Z, 12Z-octadecadienoate)-3-(9Z, 12Z, 15Z-octadecatrienoate) (8), glycerol 1, 2, 3-tri-(9Z, 12Z-octadecadienoate) (9), glycerol 1, 2, 3-tri-(9Z, 12Z, 15Z-octadecatrienoate) (10), glycerol 1-hexadecanoate-2, 3-di-(9Z, 12Z-octadecadienoate) (11) on the basis of EI-MS, FAB-MS and NMR spectra. Moreover, 35 volatile compounds were identified by GC-MS.

  13. Corrosion effects of runway de-icing chemicals on aircraft alloys and coatings

    Energy Technology Data Exchange (ETDEWEB)

    Huttunen-Saarivirta, E., E-mail: elina.huttunen-saarivirta@tut.fi [Department of Materials Science, Tampere University of Technology, P.O. Box 589, FI-33101 Tampere (Finland); Kuokkala, V.-T.; Kokkonen, J. [Department of Materials Science, Tampere University of Technology, P.O. Box 589, FI-33101 Tampere (Finland); Paajanen, H. [Finnish Air Force Materiel Command, Plans Division, Support Systems Section, P.O. Box 210, FI-33101 Tampere (Finland)

    2011-03-15

    Research highlights: {yields} Corrosion effects of urea and four new runway de-icing chemicals on Al alloy 2024, Mg alloy RZ5 and cadmium-plated and subsequently chromate-treated steel 4340 were examined by three types of corrosion tests. {yields} Corrosion effects of urea on Al alloy 2024 were more pronounced than those of the new de-icing chemicals, with pitting corrosion being evident in urea in all tests. {yields} The rate of corrosion in Mg alloy RZ5 was often higher in new de-icing chemicals than in urea, although the form of corrosion was the same in most cases, i.e., general corrosion. {yields} Corrosion effects of the five runway de-icing chemicals on cadmium-plated and subsequently chromate-treated steel 4340 were slightly different in all three tests, but some loss of the coating layers was detected in all cases. - Abstract: Corrosion effects of five runway de-icing chemicals on aluminium alloy 2024, magnesium alloy RZ5 and cadmium-plated and subsequently chromate-treated steel 4340 were investigated by cyclic polarisation measurements, open circuit potential monitoring and cyclic chemical exposure tests. The runway de-icing chemicals included in the study contained urea, which has a long history as a runway de-icing chemical, and four new commercial de-icing chemicals, which were based on betaine and potassium formate. Corrosion effects of urea on aluminium alloy 2024 were more pronounced than those of the new de-icing chemicals. In urea, the breakdown potential, indicating the onset of pitting, was clearly distinguishable in the cyclic polarisation curve and pitting corrosion was detected on the specimen surface after all three types of tests. Weight losses during the chemical exposure tests were also higher for urea than for the other four chemicals, where pitting corrosion was only occasionally detected. The opposite was true in the case of magnesium alloy RZ5: although the alloy experienced general corrosion in each de-icing chemical included in the

  14. Chemical conversion coating on AZ31B magnesium alloy and its corrosion tendency

    Institute of Scientific and Technical Information of China (English)

    Hualan JIN; Xiangjie YANG; Ming WANG

    2009-01-01

    The morphology change of the magnesium matrix after pre-treatment and the mor-phology as well as the phase composition of chemical conversion coating formed by phosphate were studied using scanning electron microscope and X-ray diffraction. The corrosion resistance of the coating was studied by salt spray and damp test, and the corrosion tendency during salt immersion test was analyzed. The results show that the phase composition before and after pre-treatment is almost change- less, and the deep microflaw appears between α and β phases during acidic pickling. The phosphate conversion coating is mainly composed of Mg, MgO, and some amor-phous phase, and it can provide a good protection for the AZ31B alloy. Results from corrosive morphology indicate that the growth and the corrosion resistance of the phosphate conversion coating are related to the forming process of the AZ31B matrix.

  15. High-Throughput Industrial Coatings Research at The Dow Chemical Company.

    Science.gov (United States)

    Kuo, Tzu-Chi; Malvadkar, Niranjan A; Drumright, Ray; Cesaretti, Richard; Bishop, Matthew T

    2016-09-12

    At The Dow Chemical Company, high-throughput research is an active area for developing new industrial coatings products. Using the principles of automation (i.e., using robotic instruments), parallel processing (i.e., prepare, process, and evaluate samples in parallel), and miniaturization (i.e., reduce sample size), high-throughput tools for synthesizing, formulating, and applying coating compositions have been developed at Dow. In addition, high-throughput workflows for measuring various coating properties, such as cure speed, hardness development, scratch resistance, impact toughness, resin compatibility, pot-life, surface defects, among others have also been developed in-house. These workflows correlate well with the traditional coatings tests, but they do not necessarily mimic those tests. The use of such high-throughput workflows in combination with smart experimental designs allows accelerated discovery and commercialization.

  16. The power source effect on SiOx coating deposition by plasma enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    SiOx coatings were prepared by capacitively coupled plasma enhanced chemical vapor deposition on polyethyleneterephtalate substrates in 23 kHz middle-frequency and radio frequency power supplies, respectively, where hexamethyldisiloxane was used as gas source. The influences of discharge conditions on gas phase intermediate species and active radicals for SiOx formation was investigated by mass spectrometry as real-time in-situ diagnosis. The deposited SiOx coating chemical structures were also analyzed by Fourier transform infrared spectroscopy. Meanwhile, the film barrier property, oxygen transmission rate, was measured at 23 oC and 50% humidity circumstance. The better barrier property was obtained in the MF power source depositing SiOx coated PET.

  17. Low pressure chemical vapor deposition of niobium coating on silicon carbide

    International Nuclear Information System (INIS)

    Nb coatings were prepared on a SiC substrate by low pressure chemical vapor deposition using NbCl5. Thermodynamic calculations were performed to study the effect of temperature and partial pressure of NbCl5 on the final products. The as-deposited coatings were characterized by scanning electron microscopy, X-ray diffraction, and energy dispersive spectroscopy. The Nb coatings are oriented and grow in the preferred (2 0 0) plane and (2 1 1) plane, at 1173 K and 1223-1423 K, respectively. At 1123-1273 K, the deposition is controlled by the surface kinetic processes. The activation energy is found to be 133 kJ/mol. At 1273-1373 K, the deposition is controlled by the mass transport processes. The activation energy is found to be 46 kJ/mol. The growth mechanism of the chemical vapor deposited Nb is also discussed based on the morphologies and the deposition rates.

  18. Physico Chemical Analysis of Sapota (Manilkara zapota) Coated by Edible Aloe Vera Gel

    OpenAIRE

    N.Padmaja; S. John Don Bosco; J. Sudhakara Rao

    2015-01-01

    The physical and chemical characteristics of the fruit have immense significance as they ultimately affect the quality of processed productsprepared from them. Over ripening of Sapota (Manilkara zapota) fruits at the post-harvest stage usually results in dramatic decline in quality.In the present study, physico chemical analysis (which includes Weight loss, Colour, Texture, TSS, pH, TA and Ascorbic acid content) ofedible Aloe vera gel coated Sapota fruits packed in LDPE and stored at 15 ± 2? ...

  19. Elaboration of colloidal silica sols in aqueous medium: functionalities, optical properties and chemical detection of coating

    International Nuclear Information System (INIS)

    The aim of this work was to study surface reactivity of silica nanoparticles through physical and chemical properties of sols and coatings. Applications are numerous and they are illustrated in this work by optical coating preparation for laser components and chemical gas sensor development for nitroaromatics detection. On one hand, protocol synthesis of colloidal silica sols has been developed in water medium using sol-gel process (0 to 100 w%). These sols, so-called BLUESIL, are time-stable during at least one year. Homogeneous coatings having thickness fixed to 200 nm, have been prepared on silica substrate and show high porosity and high transparence. Original films have been developed using catalytic curing in gas atmosphere (ammonia curing) conferring good abrasive resistance to the coating without significant properties modification. In order to reduce film sensitivity to molecular adsorption (water, polluting agents... ), specific BLUESIL coatings have been prepared showing hydrophobic property due to apolar species grafting onto silica nanoparticles. Using this route, coatings having several functional properties such as transparence, hydrophobicity, high porosity and good abrasive resistance have been elaborated. On the other hand, we show that colloidal silica is a material specifically adapted to the detection of nitro aromatic vapors (NAC). Indeed, the use of colloidal silica as chemical gas sensor reveals very high sensitivity, selectivity to NAC compared to Volatile Organic Compound (V.O.C) and good detection performances during one year. Moreover, chemical sensors using functionalized colloidal silica have exhibited good results of detection, even in high humidity medium (≥70 %RH). (author)

  20. CHEMICALLY DEPOSITED SILVER FILM USED AS A SERS-ACTIVE OVER COATING LAYER FOR POLYMER FILM

    Institute of Scientific and Technical Information of China (English)

    Xiao-ning Liu; Gi Xue; Yun Lu; Jun Zhang; Fen-ting Li; Chen-chen Xue; Stephen Z.D. Cheng

    2001-01-01

    When colloidal silver particles were chemically deposited onto polymer film as an over-coating layer, surfaceenhanced Raman scattering (SERS) spectra could be collected for the surface analysis. SERS measurements of liquid crystal film were successfully performed without disturbing the surface morphology.

  1. Aluminium nitride coatings preparation using a chemical vapour deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Armas, B.; Combescure, C.; Icaza Herrera, M. de; Sibieude, F. [Centre National de la Recherche Scientifique (CNRS), 66 - Font-Romeu (France). Inst. de Science et du Genie des Materiaux et des Procedes

    2000-07-01

    Aluminium nitride was obtained in a cold wall reactor using AlCl{sub 3} and NH{sub 3} as precursors and N{sub 2} as a carrier gas. AlCl{sub 3} was synthesized << in situ >> by means of an original method based on the reaction of SiCl{sub 4(g)} with Al{sub (S)}. The substrate used was a cylinder of graphite coated with SiC and heated by high frequency induction. The deposition rate was studied as a function of temperature in the range 900 - 1500 C, the total pressure varying from 2 to 180 hPa. At low temperatures an Arrhenius type representation of the kinetics for several pressures indicated a thermally activated process with an apparent activation energy of about 80 kJ.mol{sup -1}. At high deposition temperatures, the deposition rate was almost constant, indicating that the growth was controlled by a diffusion process. The influence of gas composition and total AlCl{sub 3} flow rate was also discussed. The different layers were characterised particularly by means of X-ray diffraction and SEM. The influence of temperature and total pressure on crystallization and morphology was studied. (orig.)

  2. Nanocomposite Coatings Codeposited with Nanoparticles Using Aerosol-Assisted Chemical Vapour Deposition

    Directory of Open Access Journals (Sweden)

    Xianghui Hou

    2013-01-01

    Full Text Available Incorporating nanoscale materials into suitable matrices is an effective route to produce nanocomposites with unique properties for practical applications. Due to the flexibility in precursor atomization and delivery, aerosol-assisted chemical vapour deposition (AACVD process is a promising way to synthesize desired nanocomposite coatings incorporating with preformed nanoscale materials. The presence of nanoscale materials in AACVD process would significantly influence deposition mechanism and thus affect microstructure and properties of the nanocomposites. In the present work, inorganic fullerene-like tungsten disulfide (IF-WS2 has been codeposited with Cr2O3 coatings using AACVD. In order to understand the codeposition process for the nanocomposite coatings, chemical reactions of the precursor and the deposition mechanism have been studied. The correlation between microstructure of the nanocomposite coatings and the codeposition mechanism in the AACVD process has been investigated. The heterogeneous reaction on the surface of IF-WS2 nanoparticles, before reaching the substrate surface, is the key feature of the codeposition in the AACVD process. The agglomeration of nanoparticles in the nanocomposite coatings is also discussed.

  3. Physico Chemical Analysis of Sapota (Manilkara zapota Coated by Edible Aloe Vera Gel

    Directory of Open Access Journals (Sweden)

    N. Padmaja

    2015-03-01

    Full Text Available The physical and chemical characteristics of the fruit have immense significance as they ultimately affect the quality of processed productsprepared from them. Over ripening of Sapota (Manilkara zapota fruits at the post-harvest stage usually results in dramatic decline in quality.In the present study, physico chemical analysis (which includes Weight loss, Colour, Texture, TSS, pH, TA and Ascorbic acid content ofedible Aloe vera gel coated Sapota fruits packed in LDPE and stored at 15 ± 2? were studied at regular intervals of 5 days i.e., 0th,5th, 10th,15thand 20th days. The dip treatment of Aloe vera gel coating 1:2, 7 minutes had best retained the physico chemical characteristics than the othertreatments performed and was found to be the most effective treatment in maintaining the fruit quality attributes along with the shelf lifeextension of about 20 days.

  4. Application of Nanocomposite Coatings with Different Structural Physical and Chemical Characteristics in Tissue Engineering

    Directory of Open Access Journals (Sweden)

    A.N. Goltsev

    2013-03-01

    Full Text Available The research covers the results of experimental studies of the effect character of nanocomposite coatings with different physical and chemical parameters (type, roughness, hydrophilic-hydrophobic characteristics on structural and functional properties (adhesive potential, phenotype, gene expression of mesenchymal stem cells (MSCs. On the tested nanocoatings (Al2O3, ZrO2, Ta2O5 the capability of oxide coating Al2O3 to enrich the in vitro cultured bone marrow (BM with the cells of MSCs phenotype markers as well as to increase the expression rate of ido gene in them, which may extend the spectrum of their therapeutic application in clinics, has been found.

  5. Chemical bath deposition for the fabrication of antireflective coating of spherical silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Minemoto, Takashi; Takakura, Hideyuki; Hamakawa, Yoshihiro [College of Science and Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan)

    2006-12-15

    A CdS film as an antireflective (AR) coating has been successfully deposited on spherical silicon solar cells by chemical bath deposition, which is a novel deposition method of AR coatings for spherical silicon solar cells. The CBD method is a growth method in an aqueous solution and enables film formation for electronic devices with arbitrary shapes. The solar cell performance of the cell with the CdS film showed a 16% increase in short circuit current compared to that without an ARC. The result confirms that the CBD method is useful for the ARC fabrication of spherical silicon solar cells. (author)

  6. Chemical changes in DMP1-null murine bone & silica based pecvd coatings for titanium implant osseoapplications

    Science.gov (United States)

    Maginot, Megen

    In order to improve clinical outcomes in bone-implant systems, a thorough understanding of both local bone chemistry and implant surface chemistry is necessary. This study consists, therefore, of two main parts: one focused on determining the nature of the changes in bone chemistry in a DMP1-null transgenic disease model and the other on the development of amorphous silica-based coatings for potential use as titanium bone implant coatings. For the study of bone mineral in the DMP1 transgenic model, which is known to have low serum phosphate levels, transgenic DMP1-null and wild type mice were fed a high phosphate diet, sacrificed, and had their long bone harvested. This bone was characterized using SEM, FTIR, microCT and XANES and compared to DMP1-null and wild type control groups to assess the therapeutic effect of high Pi levels on the phenotype and the role of DMP1 in mineralization in vivo. Findings suggest that though the high phosphate diet results in restoring serum phosphate levels, it does not completely rescue the bone mineral phenotype at an ultrastructural level and implicates DMP1 in phosphate nucleation. Since plasma enhanced chemical vapor deposition (PECVD) silica like coatings have not previously been fabricated for use in oessoapplications, the second part of this study initially focused on the characterization of novel SiOx chemistries fabricated via a chemical vapor deposition process that were designed specifically to act as bioactive coatings with a loose, hydrogenated structure. These coatings were then investigated for their potential initial stage response to bone tissue through immersion in a simulated body fluid and through the culture of MC3T3 cells on the coating surfaces. Coating surfaces were characterized by SEM, FTIR, contact angle measurements, and XANES. Coating dissolution and ionic release were also investigated by ICP-OES. Findings suggest that some SiOx chemistries may form a bioactive coating while more highly substituted

  7. Development of Diffusion barrier coatings and Deposition Technologies for Mitigating Fuel Cladding Chemical Interactions (FCCI)

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Kumar; Allen, Todd; Cole, James

    2013-02-27

    The goal of this project is to develop diffusion barrier coatings on the inner cladding surface to mitigate fuel-cladding chemical interaction (FCCI). FCCI occurs due to thermal and radiation enhanced inter-diffusion between the cladding and fuel materials, and can have the detrimental effects of reducing the effective cladding wall thickness and lowering the melting points of the fuel and cladding. The research is aimed at the Advanced Burner Reactor (ABR), a sodium-cooled fast reactor, in which higher burn-ups will exacerbate the FCCI problem. This project will study both diffusion barrier coating materials and deposition technologies. Researchers will investigate pure vanadium, zirconium, and titanium metals, along with their respective oxides, on substrates of HT-9, T91, and oxide dispersion-strengthened (ODS) steels; these materials are leading candidates for ABR fuel cladding. To test the efficacy of the coating materials, the research team will perform high-temperature diffusion couple studies using both a prototypic metallic uranium fuel and a surrogate—the rare-earth element lanthanum. Ion irradiation experiments will test the stability of the coating and the coating-cladding interface. A critical technological challenge is the ability to deposit uniform coatings on the inner surface of cladding. The team will develop a promising non-line-of-sight approach that uses nanofluids . Recent research has shown the feasibility of this simple yet novel approach to deposit coatings on test flats and inside small sections of claddings. Two approaches will be investigated: 1) modified electrophoretic deposition (MEPD) and 2) boiling nanofluids. The coatings will be evaluated in the as-deposited condition and after sintering.

  8. Development of Diffusion barrier coatings and Deposition Technologies for Mitigating Fuel Cladding Chemical Interactions (FCCI)

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Kumar; Allen, Todd; Cole, James

    2013-02-27

    The goal of this project is to develop diffusion barrier coatings on the inner cladding surface to mitigate fuel-cladding chemical interaction (FCCI). FCCI occurs due to thermal and radiation enhanced inter-diffusion between the cladding and fuel materials, and can have the detrimental effects of reducing the effective cladding wall thickness and lowering the melting points of the fuel and cladding. The research is aimed at the Advanced Burner Reactor (ABR), a sodium-cooled fast reactor, in which higher burn-ups will exacerbate the FCCI problem. This project will study both diffusion barrier coating materials and deposition technologies. Researchers will investigate pure vanadium, zirconium, and titanium metals, along with their respective oxides, on substrates of HT-9, T91, and oxide dispersion-strengthened (ODS) steels; these materials are leading candidates for ABR fuel cladding. To test the efficacy of the coating materials, the research team will perform high-temperature diffusion couple studies using both a prototypic metallic uranium fuel and a surrogate the rare-earth element lanthanum. Ion irradiation experiments will test the stability of the coating and the coating-cladding interface. A critical technological challenge is the ability to deposit uniform coatings on the inner surface of cladding. The team will develop a promising non-line-of-sight approach that uses nanofluids . Recent research has shown the feasibility of this simple yet novel approach to deposit coatings on test flats and inside small sections of claddings. Two approaches will be investigated: 1) modified electrophoretic deposition (MEPD) and 2) boiling nanofluids. The coatings will be evaluated in the as-deposited condition and after sintering.

  9. Residual stresses in chemically vapor deposited coatings in the Ti-C-N system

    International Nuclear Information System (INIS)

    Residual stresses in chemically vapor deposited monolithic and graded coatings in the Ti-C-N system were investigated as a function of substrate material and coating composition by X-ray diffraction Sin2 Ψ method. The thermal expansion coefficients (CTEs) of the graphite substrates ranged from 2.5x10-6 K-1 to 8.6x10-6 K-1. Titanium nitride (CTE 9.35x10-6 K-1) and titanium carbide (CTE 7.5x10-6 K-1) coatings deposited on the low-expansion substrates (CTEs 2.5-3.5x10-6 K-1) exhibited crack networks which accounted for low stress levels measured in the coatings. A phenomenalogical explanation of the crack patterns was given. The coatings grown on the substrates with high coefficients of thermal expansion (CTEs 7.8-8.6x10-6 K-1) had no cracks. Residual stresses in the TiN coatings on these substrates were measured to be tensile. Whereas TiC coatings always exhibited compressive stresses ranging from -54±10 MPa to -288±18 MPa. The TiCxNy coatings deposited on the substrate with a thermal expansion coefficient of 8.6x10-6 K-1 also had compressive stresses increased with increasing TiC mole fraction in the TiCxNy up to about 0.9 above which stresses decreased. The residual stresses in the top TiC layers of the graded TiN/TiC coatings with linear, parabolic and exponentional composition profiles grown on the the same substrate (CTE 8.6x10-6 K-1) were measured to be compressive and about 475 MPa. Stresses in the coatings were calculated and attributed to the thermal expansion mismatch between the coating and the substrate. It was shown that the measured stresses were, in general, found to be in good agreement with the calculated ones. (orig.)

  10. The atmospheric chemical vapour deposition of coatings on glass

    CERN Document Server

    Sanderson, K D

    1996-01-01

    The deposition of thin films of indium oxide, tin doped indium oxide (ITO) and titanium nitride for solar control applications have been investigated by Atmospheric Chemical Vapour Deposition (APCVD). Experimental details of the deposition system and the techniques used to characterise the films are presented. Results from investigations into the deposition parameters, the film microstructure and film material properties are discussed. A range of precursors were investigated for the deposition of indium oxide. The effect of pro-mixing the vaporised precursor with an oxidant source and the deposition temperature has been studied. Polycrystalline In sub 2 O sub 3 films with a resistivity of 1.1 - 3x10 sup - sup 3 OMEGA cm were obtained with ln(thd) sub 3 , oxygen and nitrogen. The growth of ITO films from ln(thd) sub 3 , oxygen and a range of tin dopants is also presented. The effect of the dopant precursor, the doping concentration, deposition temperature and the effect of additives on film growth and microstr...

  11. Plasma Assisted Chemical Vapour Deposition – Technological Design Of Functional Coatings

    Directory of Open Access Journals (Sweden)

    Januś M.

    2015-06-01

    Full Text Available Plasma Assisted Chemical Vapour Deposition (PA CVD method allows to deposit of homogeneous, well-adhesive coatings at lower temperature on different substrates. Plasmochemical treatment significantly impacts on physicochemical parameters of modified surfaces. In this study we present the overview of the possibilities of plasma processes for the deposition of diamond-like carbon coatings doped Si and/or N atoms on the Ti Grade2, aluminum-zinc alloy and polyetherketone substrate. Depending on the type of modified substrate had improved the corrosion properties including biocompatibility of titanium surface, increase of surface hardness with deposition of good adhesion and fine-grained coatings (in the case of Al-Zn alloy and improving of the wear resistance (in the case of PEEK substrate.

  12. Nitrogen implantation effects on the chemical bonding and hardness of boron and boron nitride coatings

    Energy Technology Data Exchange (ETDEWEB)

    Anders, S; Felter, T; Hayes, J; Jankowski, A F; Patterson, R; Poker, D; Stamler, T

    1999-02-08

    Boron nitride (BN) coatings are deposited by the reactive sputtering of fully dense, boron (B) targets utilizing an argon-nitrogen (Ar-N{sub 2}) reactive gas mixture. Near-edge x-ray absorption fine structure analysis reveals features of chemical bonding in the B 1s photoabsorption spectrum. Hardness is measured at the film surface using nanoindentation. The BN coatings prepared at low, sputter gas pressure with substrate heating are found to have bonding characteristic of a defected hexagonal phase. The coatings are subjected to post-deposition nitrogen (N{sup +} and N{sub 2}{sup +}) implantation at different energies and current densities. The changes in film hardness attributed to the implantation can be correlated to changes observed in the B 1s NEXAFS spectra.

  13. Chemical composition and structural transformations of amorphous chromium coatings electrodeposited from Cr(III) electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Safonova, Olga V. [Swiss-Norwegian Beamlines at European Synchrotron Radiation Facility, 38043 Grenoble Cedex (France); Vykhodtseva, Ludmila N. [Department of Electrochemistry, Faculty of Chemistry, Moscow State University, 119991 Moscow (Russian Federation); Polyakov, Nikolai A. [A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 119991 Moscow (Russian Federation); Swarbrick, Janine C. [European Synchrotron Radiation Facility, 38043 Grenoble Cedex (France); Sikora, Marcin [European Synchrotron Radiation Facility, 38043 Grenoble Cedex (France); Department of Solid State Physics, Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Av. Mickiewicza 30, 30-059 Krakow (Poland); Glatzel, Pieter [European Synchrotron Radiation Facility, 38043 Grenoble Cedex (France); Safonov, Viktor A., E-mail: safon@elch.chem.msu.r [Department of Electrochemistry, Faculty of Chemistry, Moscow State University, 119991 Moscow (Russian Federation)

    2010-12-15

    Amorphous chromium coatings were electrodeposited from Cr(III)-based solutions containing organic (HCOONa) or phosphorus-containing (NaH{sub 2}PO{sub 2}) additives. Their structure was studied by a combination of X-ray diffraction (XRD), valence-to-core X-ray emission spectroscopy (XES) and X-ray absorption spectroscopy (XAS) at the Cr K-edge. Metalloid atoms (C or P) incorporated in electroplates structure are chemically bonded to chromium (i.e. are located in the first coordination shell). Upon annealing at elevated temperatures in vacuum, these amorphous coatings crystallize into a mixture of phases containing metallic chromium and chromium carbides or chromium phosphides. Quantitative analysis of valence-to-core XES data demonstrates that the average local structure of chromium in the amorphous coatings does not change significantly during crystallization.

  14. A Two-Level Undercut-Profile Substrate for Chemical-Solution-Based Filamentary Coated Conductors

    DEFF Research Database (Denmark)

    Wulff, Anders Christian; Lundeman, Jesper H.; Hansen, Jørn B.;

    2016-01-01

    . In the present study, the 2LUPS concept is applied to a commercial cube-textured Ni-5at.% W tape, and the surface of the 2LUPS coated with two Gd2Zr2O7 buffer layers using chemical solution deposition is examined. Except for narrow regions near the edge of upper plateaus, the plateaus are found to be covered......A recently developed two-level undercut-profile substrate (2LUPS), containing two levels of plateaus connected by a curved wall with an undercut profile, enables self-forming filaments in a coated conductor during physical line-of-sight deposition of buffer and superconducting layers...... by strongly textured Gd2Zr2O7 buffer layers after dip coating and sintering....

  15. Vanadium diffusion coating on HT-9 cladding for mitigating the fuel cladding chemical interactions

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Wei-Yang; Yang, Yong, E-mail: yongyang@ufl.edu

    2014-08-01

    Fuel cladding chemical interaction (FCCI) has been identified as one of the crucial issues for developing Ferritic/Martensitic (F/M) stainless steel claddings for metallic fuels in a fast reactor. The anticipated elevated temperature and high neutron flux can significantly aggravate the FCCI, in terms of formation of inter-diffusion and lower melting point eutectic phases. To mitigate the FCCI, vanadium carbide coating as a diffusion barrier was deposited on the HT-9 substrate using a pack cementation diffusion coating (PCDC) method, and the processing temperature was optimized down to 730 °C. A solid metallurgical bonding between the coating layer and substrate was achieved, and the coating is free from through depth cracks. The microstructural characterizations using SEM and TEM show a nanostructured grain structure. EDS/WDS and XRD analysis confirm the phase of coating layer as V{sub 2}C. Diffusion couple tests at 660 °C for 100 h demonstrate that V{sub 2}C layer with a thickness of less than 5 μm can effectively eliminate the inter-diffusion between the lanthanide cerium and HT-9 steel.

  16. Vanadium diffusion coating on HT-9 cladding for mitigating the fuel cladding chemical interactions

    Science.gov (United States)

    Lo, Wei-Yang; Yang, Yong

    2014-08-01

    Fuel cladding chemical interaction (FCCI) has been identified as one of the crucial issues for developing Ferritic/Martensitic (F/M) stainless steel claddings for metallic fuels in a fast reactor. The anticipated elevated temperature and high neutron flux can significantly aggravate the FCCI, in terms of formation of inter-diffusion and lower melting point eutectic phases. To mitigate the FCCI, vanadium carbide coating as a diffusion barrier was deposited on the HT-9 substrate using a pack cementation diffusion coating (PCDC) method, and the processing temperature was optimized down to 730 °C. A solid metallurgical bonding between the coating layer and substrate was achieved, and the coating is free from through depth cracks. The microstructural characterizations using SEM and TEM show a nanostructured grain structure. EDS/WDS and XRD analysis confirm the phase of coating layer as V2C. Diffusion couple tests at 660 °C for 100 h demonstrate that V2C layer with a thickness of less than 5 μm can effectively eliminate the inter-diffusion between the lanthanide cerium and HT-9 steel.

  17. Chemical nature of phytic acid conversion coating on AZ61 magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Pan Fusheng [College of Materials Science and Engineering, Chongqing University, Chongqing, 400044 (China); Yang Xu, E-mail: yangxu2524@yahoo.com.cn [College of Materials Science and Engineering, Chongqing University, Chongqing, 400044 (China); Chemistry Department, Third Military Medical University, Chongqing, 400038 (China); Zhang Dingfei [College of Materials Science and Engineering, Chongqing University, Chongqing, 400044 (China)

    2009-07-30

    Phytic acid (PA) conversion coating on AZ61 magnesium alloy was prepared by the method of deposition. The influences of pH, time and PA concentration on the formation process, microstructure and properties of the conversion coating were investigated. Scanning electron microscopy (SEM) was used to observe the microstructure. The chemical nature of conversion coating was investigated by energy dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) techniques. The corrosion resistance was examined by means of potentiodynamic polarization method. The adhesive ability was tested by score experiments. The results showed that the growth and microstructure of the conversion coatings were all obviously affected by pH, time and PA concentration. In 0.5 mg/ml PA solution with a pH of 5, an optimization conversion coating formed after 20 min immersion time by deposition of PA on AZ61 magnesium alloy surface through chelating with Al{sup 3+}. It made the corrosion potential E{sub corr} of sample shifted positively about 171 mV than that of the untreated sample, and the adhesive ability reached to Grade 1 (in accordance with GB/T 9286).

  18. Chemical nature of phytic acid conversion coating on AZ61 magnesium alloy

    International Nuclear Information System (INIS)

    Phytic acid (PA) conversion coating on AZ61 magnesium alloy was prepared by the method of deposition. The influences of pH, time and PA concentration on the formation process, microstructure and properties of the conversion coating were investigated. Scanning electron microscopy (SEM) was used to observe the microstructure. The chemical nature of conversion coating was investigated by energy dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) techniques. The corrosion resistance was examined by means of potentiodynamic polarization method. The adhesive ability was tested by score experiments. The results showed that the growth and microstructure of the conversion coatings were all obviously affected by pH, time and PA concentration. In 0.5 mg/ml PA solution with a pH of 5, an optimization conversion coating formed after 20 min immersion time by deposition of PA on AZ61 magnesium alloy surface through chelating with Al3+. It made the corrosion potential Ecorr of sample shifted positively about 171 mV than that of the untreated sample, and the adhesive ability reached to Grade 1 (in accordance with GB/T 9286).

  19. Chemical nature of phytic acid conversion coating on AZ61 magnesium alloy

    Science.gov (United States)

    Pan, Fusheng; Yang, Xu; Zhang, Dingfei

    2009-07-01

    Phytic acid (PA) conversion coating on AZ61 magnesium alloy was prepared by the method of deposition. The influences of pH, time and PA concentration on the formation process, microstructure and properties of the conversion coating were investigated. Scanning electron microscopy (SEM) was used to observe the microstructure. The chemical nature of conversion coating was investigated by energy dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) techniques. The corrosion resistance was examined by means of potentiodynamic polarization method. The adhesive ability was tested by score experiments. The results showed that the growth and microstructure of the conversion coatings were all obviously affected by pH, time and PA concentration. In 0.5 mg/ml PA solution with a pH of 5, an optimization conversion coating formed after 20 min immersion time by deposition of PA on AZ61 magnesium alloy surface through chelating with Al 3+. It made the corrosion potential Ecorr of sample shifted positively about 171 mV than that of the untreated sample, and the adhesive ability reached to Grade 1 (in accordance with GB/T 9286).

  20. Sputtered titanium oxynitride coatings for endosseous applications: Physical and chemical evaluation and first bioactivity assays

    Energy Technology Data Exchange (ETDEWEB)

    Banakh, Oksana, E-mail: oksana.banakh@he-arc.ch [Institute of Applied Microtechnologies, Haute Ecole Arc Ingénierie (HES-SO), Eplatures-Grise 17, CH-2300 La Chaux-de-Fonds (Switzerland); Moussa, Mira, E-mail: mira.moussa@unige.ch [Laboratory of Biomaterials, University of Geneva, 19, rue Barthelemy Menn, CH-1205 Geneva (Switzerland); Matthey, Joel, E-mail: joel.matthey@he-arc.ch [Institute of Applied Microtechnologies, Haute Ecole Arc Ingénierie (HES-SO), Eplatures-Grise 17, CH-2300 La Chaux-de-Fonds (Switzerland); Pontearso, Alessandro, E-mail: alessandro.pontearso@he-arc.ch [Institute of Applied Microtechnologies, Haute Ecole Arc Ingénierie (HES-SO), Eplatures-Grise 17, CH-2300 La Chaux-de-Fonds (Switzerland); Cattani-Lorente, Maria, E-mail: maria.cattani-lorente@unige.ch [Laboratory of Biomaterials, University of Geneva, 19, rue Barthelemy Menn, CH-1205 Geneva (Switzerland); Sanjines, Rosendo, E-mail: rosendo.sanjines@epfl.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Condensed Matter Physics, Station 3, CH-1015 Lausanne (Switzerland); Fontana, Pierre, E-mail: Pierre.Fontana@hcuge.ch [Haemostasis laboratory, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, CH-1205 Geneva (Switzerland); Wiskott, Anselm, E-mail: anselm.wiskott@unige.ch [Laboratory of Biomaterials, University of Geneva, 19, rue Barthelemy Menn, CH-1205 Geneva (Switzerland); Durual, Stephane, E-mail: stephane.durual@unige.ch [Laboratory of Biomaterials, University of Geneva, 19, rue Barthelemy Menn, CH-1205 Geneva (Switzerland)

    2014-10-30

    Highlights: • Titanium oxynitride coatings (TiN{sub x}O{sub y}) with chemical composition ranging from TiN to TiO{sub 2} were deposited by magnetron sputtering from a metallic Ti target using a mixture of O{sub 2} + N{sub 2}. • The coatings structure as well as physical, chemical and mechanical properties progressively changes as a function of oxygen content in the TiN{sub x}O{sub y.} • All TiN{sub x}O{sub y} coatings show a significantly higher level of bioactivity as compared to bare Ti substrates (1.2 to 1.4 fold increase in cell proliferation). Despite variations in surface chemistry, topography and surface tension observed on films as a function of chemical composition, no significant differences in the films’ biological activity were observed after 3 days of testing. - Abstract: Titanium oxynitride coatings (TiN{sub x}O{sub y}) are considered a promising material for applications in dental implantology due to their high corrosion resistance, their biocompatibility and their superior hardness. Using the sputtering technique, TiN{sub x}O{sub y} films with variable chemical compositions can be deposited. These films may then be set to a desired value by varying the process parameters, that is, the oxygen and nitrogen gas flows. To improve the control of the sputtering process with two reactive gases and to achieve a variable and controllable coating composition, the plasma characteristics were monitored in-situ by optical emission spectroscopy. TiN{sub x}O{sub y} films were deposited onto commercially pure (ASTM 67) microroughened titanium plates by reactive magnetron sputtering. The nitrogen gas flow was kept constant while the oxygen gas flow was adjusted for each deposition run to obtain films with different oxygen and nitrogen contents. The physical and chemical properties of the deposited films were analyzed as a function of oxygen content in the titanium oxynitride. The potential application of the coatings in dental implantology was assessed by

  1. Corrosion resistant chemical vapor deposited coatings for SiC and Si3N4

    OpenAIRE

    Graham, David W

    1993-01-01

    Silicon carbide and silicon nitride turbine engine components are susceptible to hot corrosion by molten sodium sulfate salts which are formed from impurities in the engine's fuel and air intake. Several oxide materials were identified which may be able to protect these components from corrosion and preserve their structural properties. Ta20, coatings were identified as one of the most promising candidates. Thermochemical calculations showed that the chemical vapor deposition(CVD) of tantalum...

  2. Laser induced chemical vapour deposition of TiN coatings at atmospheric pressure

    OpenAIRE

    Croonen, Y.; Verspui, G.

    1993-01-01

    Laser induced Chemical Vapour Deposition of a wide variety of materials has been studied extensively at reduced pressures. However, for this technique to be economically and industrially applicable, processes at atmospheric pressure are preferred. A model study was made on the substrate-coating system molybdenum-titaniumnitride focussing on the feasibility to deposit TiN films locally at atmospheric pressure. The results of this study turned out to be very promising. A Nd-YAG laser beam ([MAT...

  3. Surface-dependent chemical equilibrium constants and capacitances for bare and 3-cyanopropyldimethylchlorosilane coated silica nanochannels

    DEFF Research Database (Denmark)

    Andersen, Mathias Bækbo; Frey, Jared; Pennathur, Sumita;

    2011-01-01

    , and pK+ are constant and independent of surface composition. Our theoretical model consists of three parts: (i) a chemical equilibrium model of the bare or coated wall, (ii) a chemical equilibrium model of the buffered bulk electrolyte, and (iii) a self-consistent Gouy–Chapman–Stern triple-layer model...... of the electrochemical double layer coupling these two equilibrium models. To validate our model, we used both pH-sensitive dye-based capillary filling experiments as well as electro-osmotic current-monitoring measurements. Using our model we predict the dependence of ζ potential, surface charge density, and capillary...

  4. Detection of Landmine Signature using SAW-based Polymer-coated Chemical Sensor

    Directory of Open Access Journals (Sweden)

    O. K. Kannan

    2004-07-01

    Full Text Available The explosive charge within a landmine is the source for a mixture of chemical vapours that form a distinctive chemical signature indicative of a landmine. The concentrations of these compounds in the air over landmines is extremely low (parts-per-trillion or lower, well below the minimum detection limits of most field-portable chemical sensors. This paper describes a portable  surface acoustic wave-based polymer-coated sensor for the detection of hidden explosives. The sensitivity and selectivity of polymer-based sensors depend on several factors including the chemo-selective coating used, the physical properties of the vapour(s of interest, the selected transducers, and the operating conditions. The polymer-based sensor was calibrated in the  laboratory using the explosive vapour generator. The preliminary results indicated that the carbowax 1000 could be a very good chemical interface to sense low levels of chemical signature of explosive material. Response for 50 ppb of TNT vapours was observed to be 400 Hz for an exposure of 2 min.

  5. Influence of precursor solution parameters on chemical properties of calcium phosphate coatings prepared using Electrostatic Spray Deposition (ESD).

    NARCIS (Netherlands)

    Leeuwenburgh, S.C.G.; Wolke, J.G.C.; Schoonman, J.; Jansen, J.A.

    2004-01-01

    A novel coating technique, referred to as Electrostatic Spray Deposition (ESD), was used to deposit calcium phosphate (CaP) coatings with a variety of chemical properties. The relationship between the composition of the precursor solutions and the crystal and molecular structure of the deposited coa

  6. Chemical and Sensory Quality Preservation in Coated Almonds with the Addition of Antioxidants.

    Science.gov (United States)

    Larrauri, Mariana; Demaría, María Gimena; Ryan, Liliana C; Asensio, Claudia M; Grosso, Nelson R; Nepote, Valeria

    2016-01-01

    Almonds provide many benefits such as preventing heart disease due to their high content of oleic fatty acid-rich oil and other important nutrients. However, they are susceptible to oxidation reactions causing rancidity during storage. The objective of this work was to evaluate the chemical and sensory quality preservation of almonds coated with carboxymethyl cellulose and with the addition of natural and synthetic antioxidants during storage. Four samples were prepared: almonds without coating (C), almonds coated with carboxymethyl cellulose (CMC), almonds coated with CMC supplemented with peanut skins extract (E), and almonds coated with CMC and supplemented with butylhydroxytoluene (BHT). Proximate composition and fatty acid profile were determined on raw almonds. Almond samples (C, CMC, E and BHT) were stored at 40 °C for 126 d. Lipid oxidation indicators: peroxide value (PV), conjugated dienes (CD), volatile compounds (hexanal and nonanal), and sensory attributes were determined for the stored samples. Samples showed small but significant increases in PV, CD, hexanal and nonanal contents, and intensity ratings of negative sensory attributes (oxidized and cardboard). C had the highest tendency to deterioration during storage. At the end of storage (126 d), C had the highest PV (3.90 meqO2 /kg), and BHT had the lowest PV (2.00 meqO2 /kg). CMC and E samples had similar intermediate PV values (2.69 and 2.57 meqO2 /kg, respectively). CMC coating and the addition of natural (peanut skin extract) and synthetic (BHT) antioxidants provide protection to the roasted almond product.

  7. Chemical and Sensory Quality Preservation in Coated Almonds with the Addition of Antioxidants.

    Science.gov (United States)

    Larrauri, Mariana; Demaría, María Gimena; Ryan, Liliana C; Asensio, Claudia M; Grosso, Nelson R; Nepote, Valeria

    2016-01-01

    Almonds provide many benefits such as preventing heart disease due to their high content of oleic fatty acid-rich oil and other important nutrients. However, they are susceptible to oxidation reactions causing rancidity during storage. The objective of this work was to evaluate the chemical and sensory quality preservation of almonds coated with carboxymethyl cellulose and with the addition of natural and synthetic antioxidants during storage. Four samples were prepared: almonds without coating (C), almonds coated with carboxymethyl cellulose (CMC), almonds coated with CMC supplemented with peanut skins extract (E), and almonds coated with CMC and supplemented with butylhydroxytoluene (BHT). Proximate composition and fatty acid profile were determined on raw almonds. Almond samples (C, CMC, E and BHT) were stored at 40 °C for 126 d. Lipid oxidation indicators: peroxide value (PV), conjugated dienes (CD), volatile compounds (hexanal and nonanal), and sensory attributes were determined for the stored samples. Samples showed small but significant increases in PV, CD, hexanal and nonanal contents, and intensity ratings of negative sensory attributes (oxidized and cardboard). C had the highest tendency to deterioration during storage. At the end of storage (126 d), C had the highest PV (3.90 meqO2 /kg), and BHT had the lowest PV (2.00 meqO2 /kg). CMC and E samples had similar intermediate PV values (2.69 and 2.57 meqO2 /kg, respectively). CMC coating and the addition of natural (peanut skin extract) and synthetic (BHT) antioxidants provide protection to the roasted almond product. PMID:26595771

  8. Chemically vapour deposited diamond coatings on cemented tungsten carbides: Substrate pretreatments, adhesion and cutting performance

    International Nuclear Information System (INIS)

    Chemical vapour deposition (CVD) of diamond films onto Co-cemented tungsten carbide (WC-Co) tools and wear parts presents several problems due to interfacial graphitization induced by the binder phase and thermal expansion mismatch of diamond and WC-Co. Methods used to improve diamond film adhesion include substrate-modification processes that create a three-dimensional compositionally graded interface. This paper reviews substrate pretreatments and adhesion issues of chemically vapour deposited diamond films on WC-Co. The combined effect of pretreatments and substrate microstructure on the adhesive toughness and wear rate of CVD diamond in dry machining of highly abrasive materials was analyzed. The role of diamond film surface morphology on chip evacuation in dry milling of ceramics was also investigated by comparing feed forces of coated and uncoated mills. The overall tribological performance of diamond coated mills depended on coating microstructure and smoothness. The use of smother films did allow to reduce cutting forces by facilitating chip evacuation

  9. Chemical composition, morphology and optical properties of zinc sulfide coatings deposited by low-energy electron beam evaporation

    International Nuclear Information System (INIS)

    The research determines the features of formation, morphology, chemical composition and optical properties of the coatings deposited by the method, proposed for the first time, of the exposure of mechanical mixture of zinc and sulfur powders to low-energy electron beam evaporation. The findings show that the deposited coatings are characterized by high chemical and structural homogeneity in thickness. The study considers the influence of substrate temperature and thickness of the deposited layer on the morphology and the width of the formed ZnS thin layers band gap. Also was shown the possibility to form ZnS coatings with this method using the mixture of zinc and copper sulfide powders.

  10. Chemical composition, morphology and optical properties of zinc sulfide coatings deposited by low-energy electron beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Ragachev, A.V. [International Chinese-Belorussian scientific laboratory on vacuum-plasma technology, College of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Francisk Skorina Gomel State University, 104, Sovetskaya Street, Gomel 246019 (Belarus); Yarmolenko, M.A., E-mail: simmak79@mail.ru [International Chinese-Belorussian scientific laboratory on vacuum-plasma technology, College of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Francisk Skorina Gomel State University, 104, Sovetskaya Street, Gomel 246019 (Belarus); Rogachev, A.A. [International Chinese-Belorussian scientific laboratory on vacuum-plasma technology, College of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Francisk Skorina Gomel State University, 104, Sovetskaya Street, Gomel 246019 (Belarus); Gorbachev, D.L. [Francisk Skorina Gomel State University, 104, Sovetskaya Street, Gomel 246019 (Belarus); Zhou, Bing [International Chinese-Belorussian scientific laboratory on vacuum-plasma technology, College of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China)

    2014-06-01

    The research determines the features of formation, morphology, chemical composition and optical properties of the coatings deposited by the method, proposed for the first time, of the exposure of mechanical mixture of zinc and sulfur powders to low-energy electron beam evaporation. The findings show that the deposited coatings are characterized by high chemical and structural homogeneity in thickness. The study considers the influence of substrate temperature and thickness of the deposited layer on the morphology and the width of the formed ZnS thin layers band gap. Also was shown the possibility to form ZnS coatings with this method using the mixture of zinc and copper sulfide powders.

  11. ZnO-coated SMS structure interrogated by a fiber ring laser for chemical sensing

    Science.gov (United States)

    Wen, X. Y.; Huang, J.; Xiao, H.; Yang, M. H.

    2014-11-01

    A zinc oxide (ZnO)-coated single mode-multimode-single mode fiber (SMS) structure interrogated by a fiber ring laser has been developed as a chemical sensor. Response to relative humidity (RH) and ethanol volatilization was evaluated by tracking the wavelength shifts of the output laser line in different moisture environments and ethanol solutions, respectively. For humidity sensing a linear response with a measurement range of 4-96% RH, and a sensitivity of 0.06 nm per %RH were obtained. As for ethanol volatilization sensing obvious wavelength blue shift was observed for the sensor immersed in 50% and 62% ethanol solution, while no variation could be detected in pure ethanol solution (purity larger than 97%). With the advantages of low cost, ease of fabrication and sensitive response, ZnO-coated SMS interrogated with a fiber ring laser was demonstrated to be an effective sensor for humidity and ethanol volatilization sensing.

  12. ZnO-coated SMS structure interrogated by a fiber ring laser for chemical sensing

    International Nuclear Information System (INIS)

    A zinc oxide (ZnO)-coated single mode–multimode–single mode fiber (SMS) structure interrogated by a fiber ring laser has been developed as a chemical sensor. Response to relative humidity (RH) and ethanol volatilization was evaluated by tracking the wavelength shifts of the output laser line in different moisture environments and ethanol solutions, respectively. For humidity sensing a linear response with a measurement range of 4–96% RH, and a sensitivity of 0.06 nm per %RH were obtained. As for ethanol volatilization sensing obvious wavelength blue shift was observed for the sensor immersed in 50% and 62% ethanol solution, while no variation could be detected in pure ethanol solution (purity larger than 97%). With the advantages of low cost, ease of fabrication and sensitive response, ZnO-coated SMS interrogated with a fiber ring laser was demonstrated to be an effective sensor for humidity and ethanol volatilization sensing. (paper)

  13. Physical, Chemical and Biochemical Modifications of Protein-Based Films and Coatings: An Extensive Review

    Science.gov (United States)

    Zink, Joël; Wyrobnik, Tom; Prinz, Tobias; Schmid, Markus

    2016-01-01

    Protein-based films and coatings are an interesting alternative to traditional petroleum-based materials. However, their mechanical and barrier properties need to be enhanced in order to match those of the latter. Physical, chemical, and biochemical methods can be used for this purpose. The aim of this article is to provide an overview of the effects of various treatments on whey, soy, and wheat gluten protein-based films and coatings. These three protein sources have been chosen since they are among the most abundantly used and are well described in the literature. Similar behavior might be expected for other protein sources. Most of the modifications are still not fully understood at a fundamental level, but all the methods discussed change the properties of the proteins and resulting products. Mastering these modifications is an important step towards the industrial implementation of protein-based films. PMID:27563881

  14. Physical, Chemical and Biochemical Modifications of Protein-Based Films and Coatings: An Extensive Review.

    Science.gov (United States)

    Zink, Joël; Wyrobnik, Tom; Prinz, Tobias; Schmid, Markus

    2016-01-01

    Protein-based films and coatings are an interesting alternative to traditional petroleum-based materials. However, their mechanical and barrier properties need to be enhanced in order to match those of the latter. Physical, chemical, and biochemical methods can be used for this purpose. The aim of this article is to provide an overview of the effects of various treatments on whey, soy, and wheat gluten protein-based films and coatings. These three protein sources have been chosen since they are among the most abundantly used and are well described in the literature. Similar behavior might be expected for other protein sources. Most of the modifications are still not fully understood at a fundamental level, but all the methods discussed change the properties of the proteins and resulting products. Mastering these modifications is an important step towards the industrial implementation of protein-based films. PMID:27563881

  15. Characterization and corrosion behavior of phytic acid coatings, obtained by chemical conversion on magnesium substrates in physiological solution

    International Nuclear Information System (INIS)

    In order to improve the corrosion resistance of biodegradable magnesium and AZ31 magnesium alloy implants, a phytic acid coating has been applied on both substrates and their protective effect against corrosion has been assessed. The morphology and the chemical nature of the conversion coating were analyzed by SEM/EDX, XRD and FTIR. The spectra showed that the conversion coating was amorphous, and it was composed of Mg, O, and P on magnesium surface, along with Al, Zn and C on AZ31 alloy. The main coating components were chelate compounds formed by phytic acid and metallic ions. The corrosion resistance of bare and coated samples was evaluated by potentiodynamic polarization technique in Hank's solution at 37 degree centigrade. The results indicate that phytic acid conversion coatings provided a very effective protection to the magnesium substrates studied. (Author)

  16. Surface characteristic of chemically converted graphene coated low carbon steel by electro spray coating method for polymer electrolyte membrane fuel cell bipolar plate.

    Science.gov (United States)

    Kim, Jungsoo; Kim, Yang Do; Nam, Dae Geun

    2013-05-01

    Graphene was coated on low carbon steel (SS400) by electro spray coating method to improve its properties of corrosion resistance and contact resistance. Exfoliated graphite was made of the graphite by chemical treatment (Chemically Converted Graphene, CCG). CCG is distributed using dispersing agent, and low carbon steel was coated with diffuse graphene solution by electro spray coating method. The structure of the CCG was analyzed using XRD and the coating layer of surface was analyzed using SEM. Analysis showed that multi-layered graphite structure was destroyed and it was transformed in to fine layers graphene structure. And the result of SEM analysis on the surface and the cross section, graphene layer was uniformly formed with 3-5 microm thickness on the surface of substrate. Corrosion resistance test was applied in the corrosive solution which is similar to the polymer electrolyte membrane fuel cell (PEMFC) stack inside. And interfacial contact resistance (ICR) test was measured to simulate the internal operating conditions of PEMFC stack. As a result of measuring corrosion resistance and contact resistance, it could be confirmed that low carbon steel coated with CCG was revealed to be more effective in terms of its applicability as PEMFC bipolar plate. PMID:23858864

  17. High quality plasma enhanced chemical vapour deposited silicon oxide gas barrier coatings on polyester films

    International Nuclear Information System (INIS)

    Silicon oxide barrier coatings fabricated by a plasma enhanced chemical vapour deposition roll-to-roll process on polyester film have demonstrated impressive properties as a barrier to water vapour permeation. This study highlights the influence of the substrate on these coatings as we find that heat stabilised poly(ethylene terephthalate) (PET), with or without an additional acrylate primer layer, and poly(ethylene naphthalate) (PEN) produce superior composites than untreated PET film in terms of gas barrier. The barrier layers on PET and filled PET substrates, for which the barrier performance is within the detectable range of our measurement, have an activation energy to water permeation that increases with the thickness of the silica. For the thickest silica this is an increase of 26 kJ mol-1 over that from the uncoated substrate. We attribute this to the creation of highly tortuous, size-hindered pathways and the decoupling of defects as the coating is deposited in multiple passes. Using a more sensitive detection technique we measure a water vapour transmission rate value as low as 2 x 10-4 g m-2 day-1 for 1 μm thick coatings on PEN. Such a good barrier is observed for these thick coatings due to the high degree of carbon detected in the films that makes them less brittle than pure SiO2 layers. Substrate surface roughness is found to influence the morphology of the SiOx films but does not seem to adversely affect the barrier performance of the composites

  18. On-line coating of glass with tin oxide by atmospheric pressure chemical vapor deposition.

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, Mark D.; Sopko, J.F. (PPF Industries, Pittsburgh, PA); Houf, William G.; Chae, Yong Kee; McDaniel, Anthony H.; Li, M. (PPF Industries, Pittsburgh, PA); McCamy, J.W. (PPF Industries, Pittsburgh, PA)

    2006-11-01

    Atmospheric pressure chemical vapor deposition (APCVD) of tin oxide is a very important manufacturing technique used in the production of low-emissivity glass. It is also the primary method used to provide wear-resistant coatings on glass containers. The complexity of these systems, which involve chemical reactions in both the gas phase and on the deposition surface, as well as complex fluid dynamics, makes process optimization and design of new coating reactors a very difficult task. In 2001 the U.S. Dept. of Energy Industrial Technologies Program Glass Industry of the Future Team funded a project to address the need for more accurate data concerning the tin oxide APCVD process. This report presents a case study of on-line APCVD using organometallic precursors, which are the primary reactants used in industrial coating processes. Research staff at Sandia National Laboratories in Livermore, CA, and the PPG Industries Glass Technology Center in Pittsburgh, PA collaborated to produce this work. In this report, we describe a detailed investigation of the factors controlling the growth of tin oxide films. The report begins with a discussion of the basic elements of the deposition chemistry, including gas-phase thermochemistry of tin species and mechanisms of chemical reactions involved in the decomposition of tin precursors. These results provide the basis for experimental investigations in which tin oxide growth rates were measured as a function of all major process variables. The experiments focused on growth from monobutyltintrichloride (MBTC) since this is one of the two primary precursors used industrially. There are almost no reliable growth-rate data available for this precursor. Robust models describing the growth rate as a function of these variables are derived from modeling of these data. Finally, the results are used to conduct computational fluid dynamic simulations of both pilot- and full-scale coating reactors. As a result, general conclusions are

  19. The Tribological Behaviors of Three Films Coated on Biomedical Titanium Alloy by Chemical Vapor Deposition

    Science.gov (United States)

    Wang, Song; Liao, Zhenhua; Liu, Yuhong; Liu, Weiqiang

    2015-11-01

    Three thin films (DLC, a-C, and TiN) were performed on Ti6Al4V by chemical vapor deposition. Carbon ion implantation was pretreated for DLC and a-C films while Ti transition layer was pretreated for TiN film to strengthen the bonding strength. X-ray diffraction, Raman measurement, nano-hardness and nano-scratch tester, and cross-section etching by FIB method were used to analyze film characteristics. Tribological behaviors of these coatings were studied by articulation with both ZrO2 and UHMWPE balls using ball-on-disk sliding. The thickness values reached ~0.46, ~0.33, and ~1.67 μm for DLC, a-C, and TiN film, respectively. Nano-hardness of the coatings compared with that of untreated and bonding strength (critical load in nano-scratch test) values of composite coatings compared with that of monolayer film all increased significantly, respectively. Under destructive test (ZrO2 ball conterface) in bovine serum lubrication, TiN coating revealed the best wear resistance while DLC showed the worst. Film failure was mainly attributed to the plowing by hard ZrO2 ball characterized by abrasive and adhesive wear. Under normal test (UHMWPE ball conterface), all coatings showed significant improvement in wear resistance both in dry sliding and bovine serum lubrication. Both DLC and a-C films showed less surface damage than TiN film due to the self-lubricating phenomenon in dry sliding. TiN film showed the largest friction coefficient both in destructive and normal tests, devoting to the big TiN grains thus leading to much rougher surface and then a higher value. The self-lubricating film formed on DLC and a-C coating could also decrease their friction coefficients. The results indicated that three coatings revealed different wear mechanisms, and thick DLC or a-C film was more promising in application in lower stress conditions such as artificial cervical disk.

  20. Mid-infrared surface plasmon polariton chemical sensing on fiber-coupled ITO coated glass

    OpenAIRE

    Martinez, Javier; Rodenas, Airan; Aguilo, Magdalena; Fernandez, Toney; Solis, Javier; Diaz, Francesc

    2016-01-01

    A novel fiber-coupled ITO coated glass slide sensor for performing surface plasmon polariton chemical monitoring in the 3.5 um mid-IR range is reported. Efficient mid-IR fiber coupling is achieved with 3D laser written waveguides, and the coupling of glass waveguide modes to ITO SPPs is driven by the varying phase matching conditions of different aqueous analytes across the anomalous dispersion range determined by their molecular fingerprints. By means of using both a mid-IR fiber supercontin...

  1. Fluidization and coating of very dense powders by fluidized bed chemical vapour deposition

    OpenAIRE

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

    2013-01-01

    The hydrodynamic behaviour of a very dense tungsten powder, 75 µm in median diameter and 19,300 kg/m3 in grain density, has been studied in a fluidized bed at room temperature using nitrogen and argon as carrier gas. Even if fluidization was achieved, the small bed expansion indicated that it was imperfect. Then, the fluidization was studied at 400 °C in order to investigate the feasibility of coating this powder by Fluidized Bed Chemical Vapour Deposition (FBCVD). In particular, the influenc...

  2. Chemical, mechanical and antibacterial properties of silver nanocluster/silica composite coated textiles for safety systems and aerospace applications

    Energy Technology Data Exchange (ETDEWEB)

    Ferraris, S., E-mail: sara.ferraris@polito.it [Politecnico di Torino, Torino, C.so Duca degli Abruzzi 24, 10129 (Italy); Perero, S.; Miola, M.; Vernè, E. [Politecnico di Torino, Torino, C.so Duca degli Abruzzi 24, 10129 (Italy); Rosiello, A.; Ferrazzo, V.; Valletta, G. [Aero Sekur S.p.A., Aprilia, via delle Valli 46, 04011 (Italy); Sanchez, J.; Ohrlander, M. [Bactiguard AB, Biblioteksgatan 25, Box 5070, SE-10242, Stockholm (Sweden); Tjörnhammar, S.; Fokine, M.; Laurell, F. [KTH Royal Institute of Technology, Department of Applied Physics, Roslagstullsbacken 21, SE-106 91 Laserphysics, Stockholm (Sweden); Blomberg, E. [KTH Royal Institute of Technology, Div. Surface and Corrosion Science, Drottning Kristinas väg 51, SE-100 44, Stockholm (Sweden); SP Technical Research Institute of Sweden, Chemistry, Materials and Surfaces, Box 5607, SE-114 86, Stockholm (Sweden); Skoglund, S.; Odnevall Wallinder, I. [KTH Royal Institute of Technology, Div. Surface and Corrosion Science, Drottning Kristinas väg 51, SE-100 44, Stockholm (Sweden); Ferraris, M. [Politecnico di Torino, Torino, C.so Duca degli Abruzzi 24, 10129 (Italy)

    2014-10-30

    Highlights: • Silver nanoclusters-silica composite coatings were deposited on textiles. • Textiles for NBC protection suites and for aerospace applications were considered. • The coating process conferred all textiles a good antibacterial activity. • The coating does not alter the properties of bare textiles. - Abstract: This work describes the chemical, mechanical and antibacterial properties of a novel silver nanocluster/silica composite coating, obtained by sputtering, on textiles for use in nuclear bacteriological and chemical (NBC) protection suites and for aerospace applications. The properties of the coated textiles were analyzed in terms of surface morphology, silver concentration and silver release in artificial sweat and synthetic tap water, respectively. No release of silver nanoparticles was observed at given conditions. The water repellency, permeability, flammability and mechanical resistance of the textiles before and after sputtering demonstrated that the textile properties were not negatively affected by the coating. The antibacterial effect was evaluated at different experimental conditions using a standard bacterial strain of Staphylococcus aureus and compared with the behavior of uncoated textiles. The coating process conferred all textiles a good antibacterial activity. Optimal deposition conditions were elaborated to obtain sufficient antibacterial action without altering the aesthetical appearance of the textiles. The antibacterial coating retained its antibacterial activity after one cycle in a washing machine only for the Nylon based textile.

  3. Delicate refinement of surface nanotopography by adjusting TiO2 coating chemical composition for enhanced interfacial biocompatibility.

    Science.gov (United States)

    Zhao, Xiaobing; Wang, Guocheng; Zheng, Hai; Lu, Zufu; Zhong, Xia; Cheng, Xingbao; Zreiqat, Hala

    2013-08-28

    Surface topography and chemistry have significant influences on the biological performance of biomedical implants. Our aim is to produce an implant surface with favorable biological properties by dual modification of surface chemistry and topography in one single simple process. In this study, because of its chemical stability, excellent corrosion resistance, and biocompatibility, titanium oxide (TiO2) was chosen to coat the biomedical Ti alloy implants. Biocompatible elements (niobium (Nb) and silicon (Si)) were introduced into TiO2 matrix to change the surface chemical composition and tailor the thermophysical properties, which in turn leads to the generation of topographical features under specific thermal history of plasma spraying. Results demonstrated that introduction of Nb2O5 resulted in the formation of Ti0.95Nb0.95O4 solid solution and led to the generation of nanoplate network structures on the composite coating surface. By contrast, the addition of SiO2 resulted in a hairy nanostructure and coexistence of rutile and quartz phases in the coating. Additionally, the introduction of Nb2O5 enhanced the corrosion resistance of TiO2 coating, whereas SiO2 did not exert much effect on the corrosion behaviors. Compared to the TiO2 coating, TiO2 coating doped with Nb2O5 enhanced primary human osteoblast adhesion and promoted cell proliferation, whereas TiO2 coatings with SiO2 were inferior in their bioactivity, compared to TiO2 coatings. Our results suggest that the incorporation of Nb2O5 can enhance the biological performance of TiO2 coatings by changing the surface chemical composition and nanotopgraphy, suggesting its potential use in modification of biomedical TiO2 coatings in orthopedic applications. PMID:23957368

  4. Mid-infrared surface plasmon polariton chemical sensing on fiber-coupled ITO coated glass

    Science.gov (United States)

    Martínez, Javier; Ródenas, Airán; Aguiló, Magdalena; Fernandez, Toney; Solis, Javier; Díaz, Francesc

    2016-06-01

    A novel fiber-coupled ITO coated glass slide sensor for performing surface plasmon polariton chemical monitoring in the 3.5 um mid-IR range is reported. Efficient mid-IR fiber coupling is achieved with 3D laser written waveguides, and the coupling of glass waveguide modes to ITO SPPs is driven by the varying phase matching conditions of different aqueous analytes across the anomalous dispersion range determined by their molecular fingerprints. By means of using both a mid-IR fiber supercontinuum source and a diode laser the excitation of SPPs is demonstrated. The efficient optical monitoring of mid-IR SPPs in smart glass could have a broad range of applications in biological and chemical sensing.

  5. Mid-infrared surface plasmon polariton chemical sensing on fiber-coupled ITO coated glass

    CERN Document Server

    Martinez, Javier; Aguilo, Magdalena; Fernandez, Toney; Solis, Javier; Diaz, Francesc

    2016-01-01

    A novel fiber-coupled ITO coated glass slide sensor for performing surface plasmon polariton chemical monitoring in the 3.5 um mid-IR range is reported. Efficient mid-IR fiber coupling is achieved with 3D laser written waveguides, and the coupling of glass waveguide modes to ITO SPPs is driven by the varying phase matching conditions of different aqueous analytes across the anomalous dispersion range determined by their molecular fingerprints. By means of using both a mid-IR fiber supercontinuum source and a diode laser the excitation of SPPs is demonstrated. The efficient optical monitoring of mid-IR SPPs in smart glass could have a broad range of applications in biological and chemical sensing.

  6. YBCO coated conductors prepared by chemical solution deposition: A TEM study

    International Nuclear Information System (INIS)

    Recently large attention has been devoted to chemical solution deposition (CSD) as a promising method for fabricating low-cost YBCO coated conductors. We present an extensive transmission electron microscopy (TEM) cross-section analysis of CSD grown La2Zr2O7 (LZO) buffer layers on flexible Ni-5at%W substrates. The high performance of these chemical solution derived buffer layers was confirmed by a YBCO critical current density Jc of 0.84 MA/cm2 achieved for a coated conductor sample with a layer sequence Ni-5at%W/LZO (CSD)/CeO2 (CSD)/YBCO, where the YBCO film was deposited by pulsed laser deposition (PLD). TEM sample preparation was carried out by conventional mechanical polishing and ion milling techniques. TEM bright-field images of the LZO films and nickel substrates were acquired under two-beam conditions. The layer thicknesses and nanovoid size were determined for the LZO buffer layers. Moreover, the interfaces between the different layers were investigated and identified. Electron diffraction patterns were obtained in order to determine the microscopic texture of the samples. Despite the presence of nanovoids in the LZO buffer layers, they act as efficient Ni diffusion barriers

  7. Functional metal oxide coatings by molecule-based thermal and plasma chemical vapor deposition techniques.

    Science.gov (United States)

    Mathur, S; Ruegamer, T; Donia, N; Shen, H

    2008-05-01

    Deposition of thin films through vaccum processes plays an important role in industrial processing of decorative and functional coatings. Many metal oxides have been prepared as thin films using different techniques, however obtaining compositionally uniform phases with a control over grain size and distribution remains an enduring challenge. The difficulties are largely related to complex compositions of functional oxide materials, which makes a control over kinetics of nucleation and growth processes rather difficult to control thus resulting in non-uniform material and inhomogeneous grain size distribution. Application of tailor-made molecular precursors in low pressure or plasma-enhanced chemical vapor deposition (CVD) techniques offers a viable solution for overcoming thermodynamic impediments involved in thin film growth. In this paper molecule-based CVD of functional coatings is demonstrated for iron oxide (Fe2O3, Fe3O4), vanadium oxide (V2O5, VO2) and hafnium oxide (HfO2) phases followed by the characterization of their microstructural, compositional and functional properties which support the advantages of chemical design in simplifying deposition processes and optimizing functional behavior. PMID:18572690

  8. Electrochemical characteristics and surface morphology in non-chromate chemical conversion coating for Zn-electroplated steel sheets

    Institute of Scientific and Technical Information of China (English)

    Masazumi OKIDO; Ryoichi ICHINO; Seok-Ki JANG; Seong-Jong KIM

    2009-01-01

    The corrosion protection property and morphology of colloidal silica conversion films as an alternative to chemical conversion coating(CCC) films were examined. The corrosion behavior was investigated in 3%NaCI solution using electrochemical techniques. Corrosion was implied by the appearance of red rust on the specimen surface. The results show that in 3%NaCl solution, red rust appears at 15-20, 55-70, and 75-85 d on Zn-electroplated steel, colloidal silica conversion-coated specimens, and chemical conversion-coated, specimens, respectively. In the salt spray test, the colloidal silica film provides better corrosion protection than CCC film, I.e., red rust appears at 96 h on the Zn-electroplated steel sheet, at 432 h on the CCC films, and at 888 h on silica conversion coating.

  9. Depth-resolved chemical mapping of rock coatings using Laser-Induced Breakdown Spectroscopy: Implications for geochemical investigations on Mars

    Science.gov (United States)

    Lefebvre, C.; Catalá-Espí, A.; Sobron, P.; Koujelev, A.; Léveillé, R.

    2016-07-01

    We demonstrate that Laser-Induced Breakdown Spectroscopy (LIBS) is capable of identifying the presence of natural rock coatings, and we define LIBS signatures of complex multi-layered coatings. This is illustrated by detailed LIBS analysis, in Mars-simulated conditions, of a rock collected in the Svalbard Islands, and which is analogous to some altered Martian rocks. The sample is a basaltic rock with sub-mm Ca-Mg-Fe-Si rich mineral coatings. LIBS elemental analysis of several distinct regions on the surface of the rock demonstrates the variability of chemical compositions of the various coatings, which is confirmed by complementary scanning electron microscope (SEM) analysis. Furthermore, the LIBS analysis as a function of the depth at different locations shows chemical variability, indicative of penetration through thin coatings of varying composition. Fine-scale, three-dimensional LIBS analysis is of interest for identifying and characterizing coatings on martian rocks, likely originating from aqueous processes, providing a rapid chemical composition as a function of the layers and further understanding of the formation of the deposits and on planetary evolution.

  10. Investigation of microcantilever array with ordered nanoporous coatings for selective chemical detection.

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, Mark D.; Thornberg, Steven Michael (Sandia National Laboratories, Albuquerque, NM); Lee, J. -H. (Georgia Institute of Technology, Atlanta, GA); Robinson, Alex Lockwood (Sandia National Laboratories, Albuquerque, NM); Hesketh, Peter J. (Georgia Institute of Technology, Atlanta, GA); Greathouse, Jeffery A. (Sandia National Laboratories, Albuquerque, NM); Houk, Ronald J. T.

    2010-03-01

    In this paper we demonstrate the potential for novel nanoporous framework materials (NFM) such as metal-organic frameworks (MOFs) to provide selectivity and sensitivity to a broad range of analytes including explosives, nerve agents, and volatile organic compounds (VOCs). NFM are highly ordered, crystalline materials with considerable synthetic flexibility resulting from the presence of both organic and inorganic components within their structure. Detection of chemical weapons of mass destruction (CWMD), explosives, toxic industrial chemicals (TICs), and volatile organic compounds (VOCs) using micro-electro-mechanical-systems (MEMS) devices, such as microcantilevers and surface acoustic wave sensors, requires the use of recognition layers to impart selectivity. Traditional organic polymers are dense, impeding analyte uptake and slowing sensor response. The nanoporosity and ultrahigh surface areas of NFM enhance transport into and out of the NFM layer, improving response times, and their ordered structure enables structural tuning to impart selectivity. Here we describe experiments and modeling aimed at creating NFM layers tailored to the detection of water vapor, explosives, CWMD, and VOCs, and their integration with the surfaces of MEMS devices. Force field models show that a high degree of chemical selectivity is feasible. For example, using a suite of MOFs it should be possible to select for explosives vs. CWMD, VM vs. GA (nerve agents), and anthracene vs. naphthalene (VOCs). We will also demonstrate the integration of various NFM with the surfaces of MEMS devices and describe new synthetic methods developed to improve the quality of VFM coatings. Finally, MOF-coated MEMS devices show how temperature changes can be tuned to improve response times, selectivity, and sensitivity.

  11. Preparation of ZrC nano-particles reinforced amorphous carbon composite coating by atmospheric pressure chemical vapor deposition

    International Nuclear Information System (INIS)

    To eliminate cracks caused by thermal expansion mismatch between ZrC coating and carbon-carbon composites, a kind of ZrC/C composite coating was designed as an interlayer. The atmospheric pressure chemical vapor deposition was used as a method to achieve co-deposition of ZrC and C from ZrCl4-C3H6-H2-Ar source. Zirconium tetrachloride (ZrCl4) powder carrier was especially made to control accurately the flow rate. The microstructure of ZrC/C composite coating was studied using analytical techniques. ZrC/C coating shows same morphology as pyrolytic carbon. Transmission electron microscopy (TEM) shows ZrC grains with size of 10-50 nm embed in turbostratic carbon. The formation mechanism is that the growth of ZrC crystals was inhibited by surrounding pyrolytic carbon and kept as nano-particles. Fracture morphologies imply good combination between coating and substrate. The ZrC crystals have stoichiometric proportion near 1, with good crystalline but no clear preferred orientation while pyrolytic carbon is amorphous. The heating-up oxidation of ZrC/C coating shows 11.58 wt.% loss. It can be calculated that the coating consists of 74.04 wt.% ZrC and 25.96 wt.% pyrolytic carbon. The average density of the composite coating is 5.892 g/cm3 by Archimedes' principle.

  12. Synthesis of Nanocobalt Powders for an Anode Material of Lithium-Ion Batteries by Chemical Reduction and Carbon Coating

    Directory of Open Access Journals (Sweden)

    Seong-Hyeon Hong

    2014-01-01

    Full Text Available Nanosized Co powders were prepared by a chemical reduction method with and without CTAB (cetyltrimethylammonium bromide, C19H42BrN and carbon-coating heat treatment at 700°C for 1 h, and the electrochemical properties of the prepared nanosized Co powders were examined to evaluate their suitability as an anode material of Li-ion batteries. Nanosized amorphous Co-based powders could be synthesized by a chemical reduction method in which a reducing agent is added to a Co ion-dissolved aqueous solution. When the prepared nanosized Co-based powders were subjected to carbon-coating heat treatment at 700°C for 1 h, the amorphous phase was crystallized, and a Co single phase could be obtained. The Co-based powder prepared by chemical reduction with CTAB and carbon-coating heat treatment had a smaller first discharge capacity (about 557 mAh/g than the Co-based powder prepared by chemical reduction without CTAB and carbon-coating heat treatment (about 628 mAh/g. However, the former had a better cycling performance than the latter from the third cycle. The carbon-coated layers are believed to have led to quite good cycling performances of the prepared Co-based powders from the third cycle.

  13. Tantalum coating on porous Ti6Al4V scaffold using chemical vapor deposition and preliminary biological evaluation

    International Nuclear Information System (INIS)

    Porous tantalum (Ta), produced via chemical vapor deposition (CVD) of commercially pure Ta onto a vitreous carbon, is currently available for use in orthopedic applications. However, the relatively high manufacturing cost and the incapability to produce customized implant using medical image data have limited its application to gain widespread acceptance. In this study, Ta film was deposited on porous Ti6Al4V scaffolds using CVD technique. Digital microscopy and scanning electron microscopy indicated that the Ta coating evenly covered the entire scaffold structure. X-ray diffraction analysis showed that the coating consisted of α and β phases of Ta. Goat mesenchymal stem cells were seeded and cultured on the Ti6Al4V scaffolds with and without coating. The tetrazolium-based colorimetric assay exhibited better cell adhesion and proliferation on Ta-coated scaffolds compared with uncoated scaffolds. The porous scaffolds were subsequently implanted in goats for 12 weeks. Histological analysis revealed similar bone formation around the periphery of the coated and uncoated implants, but bone ingrowth is better within the Ta-coated scaffolds. To demonstrate the ability of producing custom implant for clinical applications via this technology, we designed and fabricated a porous Ti6Al4V scaffold with segmental mandibular shape derived from patient computerized tomography data. - Highlights: • Ta film was coated on porous Ti6Al4V scaffold using chemical vapor deposition. Tantalum coating allowed for higher levels of cell adhesion and proliferation. • Better new bone formation occurred inside the tantalum-coated scaffolds. • Clinical image data was integrated with EBM to fabricate customized scaffold

  14. Passivation of the surface of aluminum nanopowders by protective coatings of the different chemical origin

    Science.gov (United States)

    Kwon, Young-Soon; Gromov, Alexander A.; Strokova, Julia I.

    2007-04-01

    The results of investigation and analysis of electro-exploded aluminum nanopowders, whose surface were passivated with the following substances: liquids - nitrocellulose (NC), oleic acid (C 17H 33COOH) and stearic acid (C 17H 35COOH), suspended in kerosene and ethanol, fluoropolymer; solids - boron and nickel; gases - N 2, CO 2 and air (for a comparison) are discussed. The surface protection for the aluminum nanopowders by coatings of different chemical origins leads to the some advantages of the powders properties for an application in energetic systems, e.g. solid propellants and "green" propellants (Al-H 2O). Aluminum nanopowders with a protected surface showed the increased stability to oxidation in air during the storage period and higher reactivity by heating. The TEM-visual diagram of the formation and stabilization of the coatings on the particles has been proposed on the basis of experimental results. The kinetics of the interaction of aluminum nanopowders with air has been discussed. The recommendations concerning an efficiency of the protective "non-Al 2O 3" layers on aluminum nanoparticles were proposed.

  15. Aluminum Oxide Formation On Fecral Catalyst Support By Electro-Chemical Coating

    Directory of Open Access Journals (Sweden)

    Yang H.S.

    2015-06-01

    Full Text Available FeCrAl is comprised essentially of Fe, Cr, Al and generally considered as metallic substrates for catalyst support because of its advantage in the high-temperature corrosion resistance, high mechanical strength, and ductility. Oxidation film and its adhesion on FeCrAl surface with aluminum are important for catalyst life. Therefore various appropriate surface treatments such as thermal oxidation, Sol, PVD, CVD has studied. In this research, PEO (plasma electrolytic oxidation process was applied to form the aluminum oxide on FeCrAl surface, and the formed oxide particle according to process conditions such as electric energy and oxidation time were investigated. Microstructure and aluminum oxide particle on FeCrAl surface after PEO process was observed by FE-SEM and EDS with element mapping analysis. The study presents possibility of aluminum oxide formation by electro-chemical coating process without any pretreatment of FeCrAl.

  16. An Improved Chemical Resistance and Mechanical Durability of Hydrophobic FDTS Coatings

    Science.gov (United States)

    Kobrin, B.; Zhang, T.; Grimes, M. T.; Chong, K.; Wanebo, M.; Chinn, J.; Nowak, R.

    2006-04-01

    Chemical and mechanical stability of FDTS (perfluorodecyltrichlorosilane) hydrophobic coatings was improved by using an oxide adhesion layer followed by an in-situ vapour deposition of the FDTS self-aligned monolayer. The use of silicon oxide base layer improves stability of the FDTS film and degradation of its hydrophobic properties resulting from a continuous immersion in water and other liquids. We ascribe the improved stability of the FDTS films grown on oxide to high density and uniformity of the surface hydroxyl groups required for FDTS attachment and the resulting high quality of the FDTS monolayer. This approach shows film property improvement over traditional substrates such as silicon and aluminium but may also be particularly useful in biochemistry and micro fluidics when films are deposited on substrates with lower density of the surface hydroxyl groups.

  17. Degradation Of Environmental Barrier Coatings (EBC) Due To Chemical and Thermal Expansion Incompatibility

    Science.gov (United States)

    Lee, Kang N.; King, Deboran (Technical Monitor)

    2001-01-01

    Current environmental barrier coatings (EBCs) consist of multiple layers, with each layer having unique properties to meet the various requirements for successful EBCs. As a result, chemical and thermal expansion compatibility between layers becomes an important issue to maintaining durability. Key constituents in current EBCs are mullite (3Al2O3-2SiO2), BSAS (BaO(1-x)-SrO(x)-Al2O3-2SiO2), and YSZ (ZrO2-8 wt.% Y2O3). The mullite-BSAS combination appears benign although significant diffusion occurs. Mullite-YSZ and BSAS-YSZ combinations do not react up to 1500 C. Thermally grown SiO2- BSAS and mullite-BSAS-YSZ combinations are most detrimental, forming low melting glasses. Thermal expansion mismatch between YSZ and mullite or BSAS causes severe cracking and delamination.

  18. Comparison of optical coatings deposited by novel physical and chemical techniques

    International Nuclear Information System (INIS)

    The authors have undertaken a systematic study of various methods of depositing good quality thin films of optically interesting materials by different physical and chemical methods in an effort to identify promising techniques for producing low-absorbing, low-scatter, high damage-threshold coatings. The deposition methods studied include e-beam deposition in a UHV environment, sol-gel processes utilizing hot isostatic pressing (HIP) to densify the films, photochemical deposition using organometallic reagents entrained in inert or potentially reactive gas flows, and ion-beam deposition in a reactive environment. The deposited single-layer films were analyzed using various surface analysis techniques to provide information on film composition, stoichiometry, and impurity level

  19. The power source effect on SiO{sub x} coating deposition by plasma enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Junfeng [Laboratory of Plasma Physics and Materials, Beijing Institute of Graphic Communication, Daxing, Beijing, 102600 (China); Chen Qiang, E-mail: chenqiang@bigc.edu.c [Laboratory of Plasma Physics and Materials, Beijing Institute of Graphic Communication, Daxing, Beijing, 102600 (China); Zhang Yuefei; Liu Fuping; Liu Zhongwei [Laboratory of Plasma Physics and Materials, Beijing Institute of Graphic Communication, Daxing, Beijing, 102600 (China)

    2009-05-29

    SiOx coatings were prepared by capacitively coupled plasma enhanced chemical vapor deposition on polyethyleneterephtalate substrates in 23 kHz middle-frequency and radio frequency power supplies, respectively, where hexamethyldisiloxane was used as gas source. The influences of discharge conditions on gas phase intermediate species and active radicals for SiOx formation was investigated by mass spectrometry as real-time in-situ diagnosis. The deposited SiOx coating chemical structures were also analyzed by Fourier transform infrared spectroscopy. Meanwhile, the film barrier property, oxygen transmission rate, was measured at 23 {sup o}C and 50% humidity circumstance. The better barrier property was obtained in the MF power source depositing SiOx coated PET.

  20. Atomic Layer Deposition of Chemical Passivation Layers and High Performance Anti-Reflection Coatings on Back-Illuminated Detectors

    Science.gov (United States)

    Hoenk, Michael E. (Inventor); Greer, Frank (Inventor); Nikzad, Shouleh (Inventor)

    2014-01-01

    A back-illuminated silicon photodetector has a layer of Al2O3 deposited on a silicon oxide surface that receives electromagnetic radiation to be detected. The Al2O3 layer has an antireflection coating deposited thereon. The Al2O3 layer provides a chemically resistant separation layer between the silicon oxide surface and the antireflection coating. The Al2O3 layer is thin enough that it is optically innocuous. Under deep ultraviolet radiation, the silicon oxide layer and the antireflection coating do not interact chemically. In one embodiment, the silicon photodetector has a delta-doped layer near (within a few nanometers of) the silicon oxide surface. The Al2O3 layer is expected to provide similar protection for doped layers fabricated using other methods, such as MBE, ion implantation and CVD deposition.

  1. A note on chemical composition and origin of ferromanganese oxide coated and uncoated pumice samples from central Indian Ocean basin

    Digital Repository Service at National Institute of Oceanography (India)

    Pattan, J.N.; Parthiban, G.; Moraes, C.; Rajalakshmi, R.; Lekshmi, S.; Athira, S.; JaiSankar, S.

    version: J. Geol. Soc. India, vol.87(1); 2016; 62-68 A note on Chemical Composition and Origin of Ferromanganese Oxide Coated and Uncoated Pumice samples from Central Indian Ocean Basin J. N. PATTAN1*, G. PARTHIBAN1, C. MORAES1, R...

  2. Study on CexLa1-xO2 Buffer Layer used in Coated Conductors by Chemical Solution Method

    DEFF Research Database (Denmark)

    Zhao, Yue; Suo, Hongli; Grivel, Jean-Claude;

    2009-01-01

    Developing multi-functional single buffer layer is one of the most important challenges for simplification of coated conductors configuration. Ladoped CeO2 films were prepared by chemical solution method. And surface morphology and texture quality of the La-doped CeO2 films were investigated...

  3. Mid-infrared surface plasmon polariton chemical sensing on fiber-coupled ITO coated glass.

    Science.gov (United States)

    Martínez, Javier; Ródenas, Airán; Aguiló, Magdalena; Fernandez, Toney; Solis, Javier; Díaz, Francesc

    2016-06-01

    A novel fiber-coupled indium tin oxide (ITO) coated glass slide sensor for performing surface plasmon polariton chemical monitoring in the ∼3.5  μm mid-infrared (IR) range is reported. Efficient mid-IR fiber coupling is achieved with 3D laser written waveguides, and the coupling of glass waveguide modes to ITO surface plasmon polaritons (SPPs) is driven by the varying phase matching conditions of different aqueous analytes across the anomalous dispersion range determined by their molecular fingerprints. By means of using both a mid-IR fiber supercontinuum source and a diode laser, the excitation of SPPs is demonstrated. The sensor sensitivity is tested by discriminating CH from OH features of ethanol in water solutions, demonstrating an instrumental ethanol limit of detection of 0.02% in a wide concentration range of at least 0%-50%. The efficient optical monitoring of mid-IR SPPs in smart glass could have a broad range of applications in biological and chemical sensing. PMID:27244397

  4. Conductive zinc oxide thin film coatings by combustion chemical vapour deposition at atmospheric pressure

    International Nuclear Information System (INIS)

    We have established a combustion chemical vapour deposition (C-CVD) system for the deposition of zinc oxide (ZnO) at atmospheric pressure. This C-CVD process has the advantage of a short exposure of the substrates to the flame. It is also potentially applicable as an inline coating system. Fundamental studies were performed on undoped ZnO. The specific resistivity of these layers strongly depends on the film thickness and decreases with increasing thickness. As the lowest resistivities, values of about 2.0 · 10−1 Ωcm are achieved. Ultra-violet photoemission spectra show the valence band structure of the deposited ZnO. The work function and valence band edge were determined. UV–vis spectra were taken to investigate the transmission of the coated glass samples. From these spectra the band gap energy was obtained. Raman spectroscopy as well as infrared spectroscopy confirmed the presence of ordered ZnO crystallites. The X-ray diffraction verified this result and illustrates the hexagonal structure. In the mid-infrared range precursor deposits were detected for low substrate temperatures. - Highlights: ► Zinc oxide (ZnO) films are conductive in the range of 2.0 · 10−1 Ωcm. ► X-ray diffraction, Raman and infrared spectroscopy indicate crystalline ZnO films. ► Precursor deposits were proved within the films for low growing temperatures. ► Band gap energy changes are achieved due to different growing temperatures

  5. Chemical, mechanical and antibacterial properties of silver nanocluster/silica composite coated textiles for safety systems and aerospace applications

    Science.gov (United States)

    Ferraris, S.; Perero, S.; Miola, M.; Vernè, E.; Rosiello, A.; Ferrazzo, V.; Valletta, G.; Sanchez, J.; Ohrlander, M.; Tjörnhammar, S.; Fokine, M.; Laurell, F.; Blomberg, E.; Skoglund, S.; Odnevall Wallinder, I.; Ferraris, M.

    2014-10-01

    This work describes the chemical, mechanical and antibacterial properties of a novel silver nanocluster/silica composite coating, obtained by sputtering, on textiles for use in nuclear bacteriological and chemical (NBC) protection suites and for aerospace applications. The properties of the coated textiles were analyzed in terms of surface morphology, silver concentration and silver release in artificial sweat and synthetic tap water, respectively. No release of silver nanoparticles was observed at given conditions. The water repellency, permeability, flammability and mechanical resistance of the textiles before and after sputtering demonstrated that the textile properties were not negatively affected by the coating. The antibacterial effect was evaluated at different experimental conditions using a standard bacterial strain of Staphylococcus aureus and compared with the behavior of uncoated textiles. The coating process conferred all textiles a good antibacterial activity. Optimal deposition conditions were elaborated to obtain sufficient antibacterial action without altering the aesthetical appearance of the textiles. The antibacterial coating retained its antibacterial activity after one cycle in a washing machine only for the Nylon based textile.

  6. Tantalum coating on porous Ti6Al4V scaffold using chemical vapor deposition and preliminary biological evaluation.

    Science.gov (United States)

    Li, Xiang; Wang, Lin; Yu, Xiaoming; Feng, Yafei; Wang, Chengtao; Yang, Ke; Su, Daniel

    2013-07-01

    Porous tantalum (Ta), produced via chemical vapor deposition (CVD) of commercially pure Ta onto a vitreous carbon, is currently available for use in orthopedic applications. However, the relatively high manufacturing cost and the incapability to produce customized implant using medical image data have limited its application to gain widespread acceptance. In this study, Ta film was deposited on porous Ti6Al4V scaffolds using CVD technique. Digital microscopy and scanning electron microscopy indicated that the Ta coating evenly covered the entire scaffold structure. X-ray diffraction analysis showed that the coating consisted of α and β phases of Ta. Goat mesenchymal stem cells were seeded and cultured on the Ti6Al4V scaffolds with and without coating. The tetrazolium-based colorimetric assay exhibited better cell adhesion and proliferation on Ta-coated scaffolds compared with uncoated scaffolds. The porous scaffolds were subsequently implanted in goats for 12weeks. Histological analysis revealed similar bone formation around the periphery of the coated and uncoated implants, but bone ingrowth is better within the Ta-coated scaffolds. To demonstrate the ability of producing custom implant for clinical applications via this technology, we designed and fabricated a porous Ti6Al4V scaffold with segmental mandibular shape derived from patient computerized tomography data. PMID:23623123

  7. Mechanical properties of chemically bonded sand core materials dipped in sol-gel coating impregnated with filter

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat

    2012-01-01

    A novel sol-gel coating impregnated with filter dust was applied on chemically bonded sand core materials by dipping. After curing, the strengths of the core materials were measured under uniaxial loading using a new strength testing machine (STM). The STM presents the loading history as a force......-displacement curve from which the mechanical properties of the materials are deduced. The fracture surfaces were examined using a stereomicroscope and a scanning electron microscope. From the results, the strengths of the core materials were slightly reduced by the coating in tensile and flexural modes, while...... the strengths were increased under compression. The mode of fracture of the chemically bonded sand core materials was observed to be intergranular through the binder. The stiffness of the chemically bonded sand core materials was determined. For better understanding of the mechanical properties...

  8. Comparison of physical Characteristics and cell culture test of hydroxyapatite/collagen composite coating on NiTi SMA: electrochemical deposition and chemically biomimetic growth

    Institute of Scientific and Technical Information of China (English)

    HU Kai; YANG Xianjin; CAI Yanli; CUI Zhenduo; WEI Qiang

    2007-01-01

    A hydroxyapatite(HA)/collagen(COL)composite coating on NiTi shape memory alloy (SMA)was prepared by electrochemical deposition(ELD)in modified simulated body fluid (MSBF).To draw comparisons of physical characteristics and bioactivity of the composite coating,the HA/COL composite coating was also prepared by chemically biomimetic growth (BG)and the ELD coating was re-soaked in MSBF again for further biomimetic growth(called EBG method in this paper).It was indicated that the c-axis of HA crystals was oriented parallel to the longitudinal direction of the COL fibril in BG and EBG coating,which could not found in ELD coating.The EBG method could induce a denser,thicker and better crystallized HA/COL coating.The cell culture test indicated that the BG coating presented better cell biocompatibility.

  9. Metal organic chemical vapor deposition of environmental barrier coatings for the inhibition of solid deposit formation from heated jet fuel

    Science.gov (United States)

    Mohan, Arun Ram

    Solid deposit formation from jet fuel compromises the fuel handling system of an aviation turbine engine and increases the maintenance downtime of an aircraft. The deposit formation process depends upon the composition of the fuel, the nature of metal surfaces that come in contact with the heated fuel and the operating conditions of the engine. The objective of the study is to investigate the effect of substrate surfaces on the amount and nature of solid deposits in the intermediate regime where both autoxidation and pyrolysis play an important role in deposit formation. A particular focus has been directed to examining the effectiveness of barrier coatings produced by metal organic chemical vapor deposition (MOCVD) on metal surfaces for inhibiting the solid deposit formation from jet fuel degradation. In the first part of the experimental study, a commercial Jet-A sample was stressed in a flow reactor on seven different metal surfaces: AISI316, AISI 321, AISI 304, AISI 347, Inconel 600, Inconel 718, Inconel 750X and FecrAlloy. Examination of deposits by thermal and microscopic analysis shows that the solid deposit formation is influenced by the interaction of organosulfur compounds and autoxidation products with the metal surfaces. The nature of metal sulfides was predicted by Fe-Ni-S ternary phase diagram. Thermal stressing on uncoated surfaces produced coke deposits with varying degree of structural order. They are hydrogen-rich and structurally disordered deposits, spherulitic deposits, small carbon particles with relatively ordered structures and large platelets of ordered carbon structures formed by metal catalysis. In the second part of the study, environmental barrier coatings were deposited on tube surfaces to inhibit solid deposit formation from the heated fuel. A new CVD system was configured by the proper choice of components for mass flow, pressure and temperature control in the reactor. A bubbler was designed to deliver the precursor into the reactor

  10. Microstructure and formation mechanism of Ce-based chemical conversion coating on 6063 Al alloy

    Institute of Scientific and Technical Information of China (English)

    CHEN Dong-chu; LI Wen-fang; GONG Wei-hui; WU Gui-xiang; WU Jian-feng

    2009-01-01

    In order to accelerate the conversion coating formation on 6063 Al alloy in the Ce(NO3)3 solution, accelerants of chloride and ammonium salt were used. The coating morphology, composition and structure were analyzed with SEM/EDS, EPMA, XPS and XRD. The coating morphology is influenced by the composition, pH value and temperature of the treating solution. The coating composed of metal oxide, metal hydroxide and hydrate appears to be amorphous. The elements in the coating are Al, Ce, O, Mn and Mg, while the Ce element exists in the forms of Ce3+ and Ce4+. The accelerant of chloride can increase the compactness and Ce content of the coating, so the coating corrosion resistance is remarkably improved. A scheme for the electrochemical reaction in the coating formation was proposed, and the potential change in the coating formation was also studied. It is found that chloride can shorten the time period of the first and the second stages in coating formation.

  11. Application of mechano-chemical synthesis for protective coating on steel grinding media prior to ball milling of copper

    Indian Academy of Sciences (India)

    Indranil Lahiri; K Balasubramanian

    2007-04-01

    One of the major sources of contamination during mechanical milling/alloying is from the surface erosion of the container and the grinding medium. This can either be prevented by using grinding medium and container of same material of the milled material or by adding a coating of the milled material on them. The paper describes the observations made during a mechano-chemical reaction, being used for coating the balls and vials in a planetary ball mill. Visual observation, XRD, optical micrography and EDS analysis were used to understand the progress of the reaction. Copper was successfully coated on the steel balls and vials. The method can easily be adopted in daily production purposes, prior to mechanical milling of a Cu-based powder for prevention of Fe contamination.

  12. Atmospheric pressure plasma-initiated chemical vapor deposition (AP-PiCVD) of poly(diethylallylphosphate) coating: a char-forming protective coating for cellulosic textile.

    Science.gov (United States)

    Hilt, Florian; Boscher, Nicolas D; Duday, David; Desbenoit, Nicolas; Levalois-Grützmacher, Joëlle; Choquet, Patrick

    2014-01-01

    An innovative atmospheric pressure chemical vapor deposition method toward the deposition of polymeric layers has been developed. This latter involves the use of a nanopulsed plasma discharge to initiate the free-radical polymerization of an allyl monomer containing phosphorus (diethylallylphosphate, DEAP) at atmospheric pressure. The polymeric structure of the film is evidence by mass spectrometry. The method, highly suitable for the treatment of natural biopolymer substrate, has been carried out on cotton textile to perform the deposition of an efficient and conformal protective coating.

  13. Surface chemical functionalisation of epoxy photoresist-based microcantilevers with organic-coated TiO2 nanocrystals

    DEFF Research Database (Denmark)

    Ingrosso, C.; Sardella, E.; Keller, S. S.;

    2012-01-01

    , in ambient atmosphere and without applying any external driving force or chemical activation of the epoxy photoresist surface. Atomic force microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy investigation demonstrate the spontaneous chemical anchoring of the organic......In this Letter, a solution-based approach has been used for chemically immobilising oleic acid (OLEA)-capped TiO2 nanocrystals (NCs) on the surface of microcantilevers formed of SU-8, a negative tone epoxy photoresist. The immobilisation has been carried out at room temperature, under visible light......-coated TiO2 NCs on the microcantilevers, which resulted in a highly interconnected nanoporous multilayer structure. The chemical and morphological characterisation shows that the immobilised NCs do not change either their pristine morphology or the chemical structure after binding. Spectroscopic...

  14. Effects of chemical coating with Ni on electrochemical properties of Mg2Ni hydrogen storage alloys

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The effects of nickel coating on the electrochemical properties of Mg2Ni hydrogen storage alloys are presented in this paper. X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques were employed to examine the crystal structure and surface morphologies of the bare and Ni-coated Mg2Ni alloys. The electrochemical properties of alloys were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results showed that Ni coating not only decreased the charge transfer resistance, but also decreased the H atom diflusion resistance for Mg2Ni alloys. It was also found that Ni coating effectively improved the discharge capacity, but decreased the cycling performance of the as-synthesized Ni-coated Mg2Ni alloys. The discharge current has a great impact on the cycling performance of the as-synthesized Ni-coated Mg2Ni alloys.

  15. Phase Stability of Ce-Modified La2Zr2O7 Coatings and Chemical Compatibility with YSZ

    Science.gov (United States)

    Wu, Qiong; Ji, Xiaojuan; Peng, Haoran; Ren, Xianjing; Yu, Yueguang

    2016-04-01

    Ce-modified La2Zr2O7 powders, i.e., La2Zr2O7 (LZ), La2(Zr0.7Ce0.3)2O7 (LZ7C3), and La2(Zr0.3Ce0.7)2O7 (LZ3C7), were used to produce thermal barrier coatings by atmospheric plasma spray process. The chemical compatibility of the CeO2-doped La2Zr2O7 with the traditional YSZ was investigated in LZ-YSZ powder mixtures and LZ-YSZ bilayer coatings by x-ray diffraction and scanning electron microscope. The powder mixtures and coatings were aged at 1200 and 1300 °C for 100 h. The results showed that LZ and LZ7C3 presented single pyrochlore structure after the heat treatments at both 1200 and 1300 °C. For LZ3C7, however, fluorite structure was observed at 1300 °C, indicating a poor phase stability of LZ3C7 at the elevated temperature. The results further showed that La2(Zr0.3Ce0.7)2O7 reacted with YSZ in the bilayer ceramic coatings due to the diffusion of cerium, zirconium, and yttrium. While for La2Zr2O7(LZ) and La2(Zr0.7Ce0.3)2O7, a better chemical compatibility with YSZ was shown.

  16. Surface modification of reverse osmosis desalination membranes by thin-film coatings deposited by initiated chemical vapor deposition

    International Nuclear Information System (INIS)

    Thin-film polymeric reverse osmosis membranes, due to their high permeation rates and good salt rejection capabilities, are widely used for seawater desalination. However, these membranes are prone to biofouling, which affects their performance and efficiency. In this work, we report a method to modify the membrane surface without damaging the active layer or significantly affecting the performance of the membrane. Amphiphilic copolymer films of hydrophilic hydroxyethylmethacrylate and hydrophobic perfluorodecylacrylate (PFA) were synthesized and deposited on commercial RO membranes using an initiated chemical vapor deposition technique which is a polymer deposition technique that involves free-radical polymerization initiated by gas-phase radicals. Relevant surface characteristics such as hydrophilicity and roughness could be systematically controlled by varying the polymer chemistry. Increasing the hydrophobic PFA content in the films leads to an increase in the surface roughness and hydrophobicity. Furthermore, the surface morphology studies performed using the atomic force microscopy show that as the thickness of the coating increases average surface roughness increases. Using this knowledge, the coating thickness and chemistry were optimized to achieve high permeate flux and to reduce cell attachment. Results of the static bacterial adhesion tests show that the attachment of bacterial cells is significantly reduced on the coated membranes. - Highlights: • Thin films are deposited on reverse osmosis membranes. • Amphiphilic thin films are resistant to protein attachment. • The permeation performance of the membranes is not affected by the coating. • The thin film coatings delayed the biofouling

  17. Surface modification of reverse osmosis desalination membranes by thin-film coatings deposited by initiated chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ozaydin-Ince, Gozde, E-mail: gozdeince@sabanciuniv.edu [Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Matin, Asif, E-mail: amatin@mit.edu [Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Khan, Zafarullah, E-mail: zukhan@mit.edu [Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Zaidi, S.M. Javaid, E-mail: zaidismj@kfupm.edu.sa [Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Gleason, Karen K., E-mail: kkgleasn@mit.edu [Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2013-07-31

    Thin-film polymeric reverse osmosis membranes, due to their high permeation rates and good salt rejection capabilities, are widely used for seawater desalination. However, these membranes are prone to biofouling, which affects their performance and efficiency. In this work, we report a method to modify the membrane surface without damaging the active layer or significantly affecting the performance of the membrane. Amphiphilic copolymer films of hydrophilic hydroxyethylmethacrylate and hydrophobic perfluorodecylacrylate (PFA) were synthesized and deposited on commercial RO membranes using an initiated chemical vapor deposition technique which is a polymer deposition technique that involves free-radical polymerization initiated by gas-phase radicals. Relevant surface characteristics such as hydrophilicity and roughness could be systematically controlled by varying the polymer chemistry. Increasing the hydrophobic PFA content in the films leads to an increase in the surface roughness and hydrophobicity. Furthermore, the surface morphology studies performed using the atomic force microscopy show that as the thickness of the coating increases average surface roughness increases. Using this knowledge, the coating thickness and chemistry were optimized to achieve high permeate flux and to reduce cell attachment. Results of the static bacterial adhesion tests show that the attachment of bacterial cells is significantly reduced on the coated membranes. - Highlights: • Thin films are deposited on reverse osmosis membranes. • Amphiphilic thin films are resistant to protein attachment. • The permeation performance of the membranes is not affected by the coating. • The thin film coatings delayed the biofouling.

  18. Antireflection coating formed by plasma-enhanced chemical-vapor deposition for terahertz-frequency germanium optics

    Science.gov (United States)

    Hosako, Iwao

    2003-07-01

    A method of manufacturing optical coatings for germanium optics used at terahertz frequencies has been developed. The various optical coatings used at terahertz frequencies are difficult to manufacture conventionally because these coatings must be as thick as several tens of micrometers, which is far thicker than those used in the optical region. One way to overcome this problem is to form a silicon oxide layer through plasma-enhanced chemical-vapor deposition, with silane (SiH4) as a source gas. Using this method, I formed 21-μm-thick silicon oxide films as antireflection (AR) layers for germanium optics and obtained low reflection at 1.7 THz (wavelength, λ = 175 μm). This method is easily applied to large-aperture optics and micro-optics as well as to optics with a complex surface form. The AR coatings can also be formed for photoconductive detectors made from germanium doped with gallium at a low temperature (160 °C) this low temperature ensures that the doped impurities in the germanium do not diffuse. Fabrication of optical coatings upon substrates that have refractive indices of 3.84-11.7 may also be possible by control of the refractive indices of the deposited layers.

  19. Thermal Barrier Coatings Chemically and Mechanically Resistant to High Temperature Attack by Molten Ashes

    Science.gov (United States)

    Gledhill, Andrew

    Thermal barrier coatings (TBCs) are ceramic coatings used on component in the hottest sections of gas turbine engines, used for power generation and aviation. These coatings insulate the underlying metal components and allow for much higher engine operating temperatures, improving the engine efficiency. These increase temperatures engender a new set of materials problems for TBCs. Operating temperatures in engines are now high enough for silicate impurities, either present in the fuel or ingested into the engines, to melt and adhere to the surface of the TBCs. The effects of four such impurities, two coal fly ashes, a petroleum coke-fly ash blend, and volcanic ash from the Eyjafjallajokull volcano were tested with conventional yttria-stabilized zirconia (YSZ) coatings, and found to penetrate through the entire thickness of the coating. This penetration reduces the strain tolerance of the coatings, and can result in premature failure. Testing on a newly built thermal gradient burner rig with simultaneous injection of ash impurities has shown a reduction of life up to 99.6% in these coatings when ash is present. Coatings of an alternative ceramic, gadolinium zirconate (Gd2Zr 2O7), were found to form a dense reaction layer with each of these impurities, preventing further penetration of the molten ash. This dense layer also reduces the strain tolerance, but these coatings were found to have a significantly higher life than the YSZ coatings. Testing with a small amount of ash baked onto the samples showed thirteen times the life of YSZ coatings. When the ash is continuously sprayed onto the hot sample, the life of the Gd2Zr2O7 coatings was nearly twice that of the YSZ. Finally, a delamination model was employed to explain the degradation of both types of coatings. This elastic model that takes into account the degree of penetration, differential cooling in thermal gradient testing, and thermal expansion mismatch with the underlying substrate, predicted the failure of

  20. Analyses on the U-Mo/Al Chemical Interaction and the Effects of Diffusion Barrier Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Ho Jin; Kim, Woo Jeong; Cho, Woo Hyung; Jeong, Yong Jin; Lee, Yoon Sang; Park, Jong Man; Kim, Chang Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    While many HEU-fueled research reactors have been converted by adopting LEU U{sub 3}Si{sub 2} fuel in harmony with the Reduced Enrichment for Research and Test Reactors (RERTR) program, some high performance research reactors still need the development of advanced fuels with higher uranium densities. Currently, gamma-phase U-Mo alloys are considered promising candidates to be used as high uranium density fuel for the high performance reactors. For the production of UMo alloy powder, the centrifugal atomization technology developed by KAERI has been considered the most promising way because of high yield production and excellent powder quality when compared with other possible methods such as grinding, machining or hydriding-dehydriding. However, severe pore formation associated with an extensive interaction between the U-Mo and Al matrix, although the irradiation performance of U-Mo itself showed most stable, delay the fuel qualification of UMo fuel for high performance research reactors. Because the reaction products, i.e. uranium aluminides (UAlx), is less dense than the mixed reactants, the volume of the fuel meat increases after formation of interaction layer(IL). In addition to the impact on the swelling performance, the reaction layers between the U-Mo and Al matrix induces a degradation of the thermal conductivities of the U-Mo/Al dispersion fuels. The chemical interaction between the U-Mo and Al matrix are analyzed in this study to find remedies to reduce the growth of the interaction layers during irradiation. In addition, various coating technologies for the formation of diffusion barriers on U-Mo particles are proposed as a result of the analyses

  1. Improvement on the electrochemical characteristics of graphite anodes by coating of the pyrolytic carbon using tumbling chemical vapor deposition

    International Nuclear Information System (INIS)

    The electrochemical characteristics of graphite coated with pyrolytic carbon materials using tumbling chemical vapor deposition (CVD) process have been studied for the active material of anodes in lithium ion secondary batteries. Coating of pyrolytic carbons on the surface of graphite particles, which tumble in a rotating reactor tube, was performed through the pyrolysis of liquid propane gas (LPG). The surface morphology of these graphite particles coated with pyrolytic carbon has been observed with scanning electron microscopy (SEM). The surface of graphite particles can well be covered with pyrolytic carbon by tumbling CVD. High-resolution transmission electron microscopy (HRTEM) image of these carbon particles shows that the core part is highly ordered carbon, while the shell part is disordered carbon. We have found that the new-type carbon obtained from tumbling CVD has a uniform core (graphite)-shell (pyrolytic carbon) structure. The electrochemical property of the new-type carbons has been examined using a charge-discharge cycler. The coating of pyrolytic carbon on the surface of graphite can effectively reduce the initial irreversible capacity by 47.5%. Cyclability and rate-capability of theses carbons with the core-shell structure are much better than those of bare graphite. From electrochemical impedance spectroscopy (EIS) spectra, it is found that the coating of pyrolytic carbon on the surface of graphite causes the decrease of the contact resistance in the carbon electrodes, which means the formation of solid electrolyte interface (SEI) layer is suppressed. We suggest that coating of pyrolytic carbon by the tumbling CVD is an effective method in improving the electrochemical properties of graphite electrodes for lithium ion secondary batteries

  2. Protein corona composition of superparamagnetic iron oxide nanoparticles with various physico-chemical properties and coatings.

    Science.gov (United States)

    Sakulkhu, Usawadee; Mahmoudi, Morteza; Maurizi, Lionel; Salaklang, Jatuporn; Hofmann, Heinrich

    2014-01-01

    Because of their biocompatibility and unique magnetic properties, superparamagnetic iron oxide nanoparticles NPs (SPIONs) are recognized as some of the most prominent agents for theranostic applications. Thus, understanding the interaction of SPIONs with biological systems is important for their safe design and efficient applications. In this study, SPIONs were coated with 2 different polymers: polyvinyl alcohol polymer (PVA) and dextran. The obtained NPs with different surface charges (positive, neutral, and negative) were used as a model study of the effect of surface charges and surface polymer materials on protein adsorption using a magnetic separator. We found that the PVA-coated SPIONs with negative and neutral surface charge adsorbed more serum proteins than the dextran-coated SPIONs, which resulted in higher blood circulation time for PVA-coated NPs than the dextran-coated ones. Highly abundant proteins such as serum albumin, serotransferrin, prothrombin, alpha-fetoprotein, and kininogen-1 were commonly found on both PVA- and dextran-coated SPIONs. By increasing the ionic strength, soft- and hard-corona proteins were observed on 3 types of PVA-SPIONs. However, the tightly bound proteins were observed only on negatively charged PVA-coated SPIONs after the strong protein elution. PMID:24846348

  3. Protein corona composition of superparamagnetic iron oxide nanoparticles with various physico-chemical properties and coatings.

    Science.gov (United States)

    Sakulkhu, Usawadee; Mahmoudi, Morteza; Maurizi, Lionel; Salaklang, Jatuporn; Hofmann, Heinrich

    2014-01-01

    Because of their biocompatibility and unique magnetic properties, superparamagnetic iron oxide nanoparticles NPs (SPIONs) are recognized as some of the most prominent agents for theranostic applications. Thus, understanding the interaction of SPIONs with biological systems is important for their safe design and efficient applications. In this study, SPIONs were coated with 2 different polymers: polyvinyl alcohol polymer (PVA) and dextran. The obtained NPs with different surface charges (positive, neutral, and negative) were used as a model study of the effect of surface charges and surface polymer materials on protein adsorption using a magnetic separator. We found that the PVA-coated SPIONs with negative and neutral surface charge adsorbed more serum proteins than the dextran-coated SPIONs, which resulted in higher blood circulation time for PVA-coated NPs than the dextran-coated ones. Highly abundant proteins such as serum albumin, serotransferrin, prothrombin, alpha-fetoprotein, and kininogen-1 were commonly found on both PVA- and dextran-coated SPIONs. By increasing the ionic strength, soft- and hard-corona proteins were observed on 3 types of PVA-SPIONs. However, the tightly bound proteins were observed only on negatively charged PVA-coated SPIONs after the strong protein elution.

  4. Plasma-Sprayed Hydroxylapatite-Based Coatings: Chemical, Mechanical, Microstructural, and Biomedical Properties

    Science.gov (United States)

    Heimann, Robert B.

    2016-06-01

    This contribution discusses salient properties and functions of hydroxylapatite (HA)-based plasma-sprayed coatings, including the effect on biomedical efficacy of coating thickness, phase composition and distribution, amorphicity and crystallinity, porosity and surface roughness, cohesion and adhesion, micro- and nano-structured surface morphology, and residual coating stresses. In addition, it will provide details of the thermal alteration that HA particles undergo in the extremely hot plasma jet that leads to dehydroxylated phases such as oxyhydroxylapatite (OHA) and oxyapatite (OA) as well as thermal decomposition products such as tri-(TCP) and tetracalcium phosphates (TTCP), and quenched phases such as amorphous calcium phosphate (ACP). The contribution will further explain the role of ACP during the in vitro interaction of the as-deposited coatings with simulated body fluid resembling the composition of extracellular fluid (ECF) as well as the in vivo responses of coatings to the ECF and the host tissue, respectively. Finally, it will briefly describe performance profiles required to fulfill biological functions of osteoconductive bioceramic coatings designed to improve osseointegration of hip endoprostheses and dental root implants. In large parts, the content of this contribution is a targeted review of work done by the author and his students and coworkers over the last two decades. In addition, it is considered a stepping stone toward a standard operation procedure aimed at depositing plasma-sprayed bioceramic implant coatings with optimum properties.

  5. Micro-chemical and -morphological features of heat treated plasma sprayed zirconia-based thermal barrier coatings

    International Nuclear Information System (INIS)

    Zirconia-based plasma-sprayed coatings are extensively used in jet and land-based engines as thermal barrier coatings (TBCs) for protecting and insulating gas turbine metal components from the extreme temperature in the hot gas extending the engine life capabilities and service performances as well as reducing fuel consumption. Zirconia-based thermal barrier coatings stabilized with yttria and ceria were prepared by means of atmospheric plasma spray (APS) and thermal treated at different temperatures. The resulting fractured heated surfaces have been studied by means of X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) combined with energy dispersive spectrometry (EDS) and secondary ion mass spectrometry (SIMS) in order to study the surface micro-chemical composition and morphology. The results disclose the variation of the stabilizing oxide amount, the occurrence of valence state modifications of cerium, impurity segregation phenomena and sintering. High temperature sintering influenced the porous microstructure leading to structural changes of the surface. This information confirmed that chemical and morphological aspects in plasma sprayed TBCs must be known in order to understand and predict relationships between the parameters of plasma spray process and TBC features, properties and performances for a better design of reliable TBCs. - Highlights: • Yttria and Ceria stabilized zirconia-based TBCs were prepared by means of atmospheric plasma spray (APS) and thermal treated at different temperatures. • The chemical and morphological structure of the fractured materials were analysed. • Morphology and structural changes of the coatings depended on the nucleation and temperature treatments. • Ceria stabilized TBCs showed higher phase stability than Yttria’s

  6. Effect of chemical composition of steel on the structure of hot – dip galvanized coating

    Directory of Open Access Journals (Sweden)

    P. Pokorny

    2016-01-01

    Full Text Available This article describes the effect of the content of conventional steel impurity elements on the thickness and composition of the zinc layer. This article is focused primarily on low-temperature, batch hot-dip galvanizing; however, the continuous coating process is also mentioned. The main discussion covers galvanizing from pure zinc melt, and only touches on galvanizing from melts with the usual amounts of aluminium (0,2 wt. %. Silicon, phosphorus, aluminium and sulfur may have an especially negative effect on the mechanical properties of the coating and its final appearance. The content of ballast carbon and manganese has a rather limited effect on composition and coating thickness.

  7. Sensory and chemical stability in coated peanuts with the addition of essential oils and synthetic antioxidants

    OpenAIRE

    Olmedo, R. H.; Nepote, V.; N. R. Grosso

    2012-01-01

    The objective of this work was to evaluate the antioxidant effect of essential oils on the oxidative stability of coated peanuts. Untreated coated peanuts (CP) and treated coated peanuts with the addition of rosemary (CP-R), oregano (CP-O) and laurel (CP-L) essential oils and BHT (CPBHT) were prepared. Peroxide values (PV) and p-anisidine values (AV) and the intensity ratings of sensory attributes by descriptive analysis were measured during 112 days of storage at room temperature (23°C). CP-...

  8. Project W-314 Polyurea Special Protective Coating (SPC) Test Plan Chemical Compatibility and Physical Characteristics Testing

    International Nuclear Information System (INIS)

    This Test Plan outlines the testing to be done on the Special Protective Coating (SPC) Polyurea which includes: Tank Waste Compatibility, Decontamination Factor Testing, and Adhesion Strength Testing after a sample has been exposed to Radiation

  9. High-Silica Rock Coatings on Mars: Constraining Secondary Silicate Mineralogy and Chemical Weathering Processes on Mars.

    Science.gov (United States)

    Kraft, M. D.; Michalski, J. R.; Sharp, T. G.

    2003-12-01

    Thermal Emission Spectrometer (TES) data have been fundamental to understanding Martian surface mineralogy. These data, however, require careful modeling based on laboratory spectroscopic measurements, and modeling of some minerals for Mars has been equivocal. Due to high degrees of spectral similarity, it is difficult to distinguishing silicate glass, clay minerals, zeolites, palagonitized glass, and other secondary products such as amorphous silica as components of surface rock spectra. Deciphering the nature of secondary mineral products on Mars is of key importance to understanding the role of water at the Martian surface over time. It is of central interest to distinguish primary glass from secondary silicate minerals, and secondary minerals from one another to better constrain the degree and mechanisms of aqueous alteration. Observations of Martian surface materials indicate some degree of atmosphere-water-rock interaction. These include nanophase ferric-iron oxides from visible/near-infrared spectroscopy, concentrated hematite deposits identified with TES, high water contents of rocks measured by the Alpha Proton X-ray Spectrometer, sulfate and halide minerals inferred from lander geochemical measurements, and carbonate minerals identified in Martian dust with TES data. Mass balance suggests that if there are oxides, salts, and carbonates there must also be secondary silicate phases present on Mars, which may be identifiable with TES. Identifying the types, distribution, and abundance (or absence) of secondary silicates will enable better constrains to be placed on Martian chemical weathering processes and the role water has played at the Martian surface. We suggest that rock coatings dominated by amorphous silica are geologically reasonable for Mars and may be consistent with TES data. Laboratory measurements of silica-coated rocks show that thin, micrometer-scale silica coatings have a substantial impact on rock spectra. Consequently, if authegenic

  10. Mathematical modelling of simultaneous solvent evaporation and chemical curing in thermoset coatings: A parameter study

    DEFF Research Database (Denmark)

    Kiil, Søren

    2011-01-01

    A mathematical model, describing the curing behaviour of a two-component, solvent-based, thermoset coating, is used to conduct a parameter study. The model includes curing reactions, solvent intra-film diffusion and evaporation, film gelation, vitrification, and crosslinking. A case study...... concentration of solvent. Simulations of solvent evaporation are compared to experimental data from a previous investigation. As part of the parameter study, mechanisms of this complex coating system are discussed....

  11. Chemical Synthesis of Highly Magnetic, Air-Stable Silica-Coated iron Particles

    Institute of Scientific and Technical Information of China (English)

    姜洪英; 钟伟; 汤怒江; 刘先松; 都有为

    2003-01-01

    Highly magnetic and air-stable silica-coated Fe particles have been prepared by a rapid and simple method. The specific magnetization of the sample can be as high as 201 Am2/kg even including silica, which is a non-magnetic material. The iron particle coated with silica is passivated and protected from oxidation. The influences of H2 reduction temperature on structure and magnetic properties are also studied.

  12. Porous Silicon & Titanium Dioxide Coatings Prepared by Atmospheric Pressure Plasma Jet Chemical Vapour Deposition Technique-A Novel Coating Technology for Photovoltaic Modules

    Directory of Open Access Journals (Sweden)

    S. Bhatt

    2011-01-01

    Full Text Available Atmospheric Pressure Plasma Jet (APPJ is an alternative for wet processes used to make anti reflection coatings and smooth substrate surface for the PV module. It is also an attractive technique because of it’s high growth rate, low power consumption, lower cost and absence of high cost vacuum systems. This work deals with the deposition of silicon oxide from hexamethyldisiloxane (HMDSO thin films and titanium dioxide from tetraisopropyl ortho titanate using an atmospheric pressure plasma jet (APPJ system in open air conditions. A sinusoidal high voltage with a frequency between 19-23 kHz at power up to 1000 W was applied between two tubular electrodes separated by a dielectric material. The jet, characterized by Tg ~ 600-800 K, was mostly laminar (Re ~ 1200 at the nozzle exit and became partially turbulent along the jet axis (Re ~ 3300. The spatially resolved emission spectra showed OH, N2, N2+ and CN molecular bands and O, H, N, Cu and Cr lines as well as the NO2 chemiluminescence continuum (450-800 nm. Thin films with good uniformity on the substrate were obtained at high deposition rate, between 800 -1000 nm.s-1, and AFM results revealed that coatings are relatively smooth (Ra ~ 2 nm. The FTIR and SEM analyses were better used to monitor the chemical composition and the morphology of the films in function of the different experimental conditions.

  13. Physico-chemical characteristics of coated silicone textured versus smooth breast implants differentially influence breast-derived fibroblast morphology and behaviour.

    Science.gov (United States)

    Valencia-Lazcano, Anai A; Alonso-Rasgado, Teresa; Bayat, Ardeshir

    2014-12-01

    Capsule formation is an inevitable consequence of silicone breast implantation. Clinically challenging dense fibrocollagenous capsular contractures occur at different rates between smooth compared to textured surfaces. Host response is influenced by several factors including implant surface texture, chemistry and interactions between cells and the extracellular matrix (ECM). Specific coatings can modify the physico-chemical properties of implant surfaces eliciting specific cellular reactions. Therefore, we evaluated the physico-chemical characteristics of coated smooth versus textured silicone breast implants on breast-derived fibroblast morphology and behaviour using (a) confocal laser microscopy, (b) Raman spectroscopy and (c) the effect of four unique protein and glycosaminoglycan (GAG) coatings (aggrecan, collagen I, fibronectin and hyaluronic acid) on breast-derived fibroblast attachment, proliferation, morphology, spreading, cytotoxicity and gene expression. Collagen I, fibronectin and hyaluronic acid coatings exhibited satisfactory fibroblast adhesion (pimplants demonstrated improved cell proliferation than uncoated surfaces (pbreast fibroblasts following the application of specific coatings on breast implant surfaces.

  14. Progress towards all-chemical superconducting YBa2Cu3O7-coated conductors

    International Nuclear Information System (INIS)

    Chemical solution deposition (CSD) has recently emerged as a very competitive technique for obtaining epitaxial films of high quality with controlled nanostructure. In particular, the all-CSD approach is considered to be one of the most promising approaches for cost-effective production of second-generation superconducting wires. The trifluoroacetate (TFA) route is a very versatile route for achieving epitaxial YBa2Cu3O7 (YBCO) layers with high critical currents. In this work, recent advances towards improvement of the performance of several conductor architectures based on the YBCO TFA process will be presented. We show that new improved anhydrous TFA precursors allow a significant shortening of the pyrolysis time (∼1.5 h), and we have increased the total film thickness in a single deposition using polymeric additives. On the other hand, further understanding of the YBCO nucleation and growth process has allowed us to obtain a controlled microstructure and high critical currents (Jc∼4-5 MA cm-2 and Ic∼300 A cm-1 width at 77 K). The growth conditions (CSD) and post-processing conditions (sputtering and CSD) for the underlying oxide cap and buffer layers (CeO2, BaZrO3, SrTiO3, La2Zr2O7 (La,Sr)MnO3) and of self-organized nanostructures (CeO2, BaZrO3) deposited by CSD have been investigated to obtain high-quality interfaces in multilayered systems. Different single-crystal or metallic substrates (YSZ-IBAD (yttrium stabilized zirconia-ion beam assisted deposition) and Ni-RABiT (rolling assisted biaxial texturing)) have been investigated and long (∼10 m) CSD biaxially textured buffers (CeO2, La2Zr2O7) have been grown on Ni-RABiT substrates using a reel-to-reel system. High-performance TFA-YBCO-coated conductors have been obtained on vacuum-based buffer layers (Ic∼140 A cm-1 width) and on CSD buffer layers grown on IBAD YSZ-SS (stainless steel) substrates. Finally, we report on recent analysis of the magnetic granularity and vortex pinning properties of TFA

  15. Effect of zinc phosphate chemical conversion coating on corrosion behaviour of mild steel in alkaline medium: protection of rebars in reinforced concrete

    Directory of Open Access Journals (Sweden)

    Florica Simescu and Hassane Idrissi

    2008-01-01

    Full Text Available We outline the ability of zinc phosphate coatings, obtained by chemical conversion, to protect mild steel rebars against localized corrosion, generated by chloride ions in alkaline media. The corrosion resistance of coated steel, in comparison with uncoated rebars and coated and uncoated steel rebars embedded in mortar, were evaluated by open-circuit potential, potentiodynamic polarization, cronoamperometry and electrochemical impedance spectroscopy. The coated surfaces were characterized by x-ray diffraction and scanning electron microscopy. First, coated mild steel rebars were studied in an alkaline solution with and without chloride simulating a concrete pore solution. The results showed that the slow dissolution of the coating generates hydroxyapatite Ca10(PO46(OH2. After a long immersion, the coating became dense and provided an effective corrosion resistance compared with the mild steel rebar. Secondly, the coated and uncoated steel rebars embedded in mortar and immersed in chloride solution showed no corrosion or deterioration of the coated steel. Corrosion rate is considerably lowered by this phosphate coating.

  16. Experimental setup for producing tungsten coated graphite tiles using plasma enhanced chemical vapor deposition technique for fusion plasma applications

    International Nuclear Information System (INIS)

    Plasma wall interaction (PWI) in fusion grade machines puts stringent demands on the choice of materials in terms of high heat load handling capabilities and low sputtering yields. Choice of suitable material still remains a challenge and open topic of research for the PWI community. Carbon fibre composites (CFC), Beryllium (Be), and Tungsten (W) are now being considered as first runners for the first wall components of future fusion machines. Tungsten is considered to be one of the suitable materials for the job because of its superior properties than carbon like low physical sputtering yield and high sputter energy threshold, high melting point, fairly high re-crystallization temperature, low fuel retention capabilities, low chemical sputtering with hydrogen and its isotopes and most importantly the reparability with various plasma techniques both ex-situ and in-situ. Plasma assisted chemical vapour deposition is considered among various techniques as the most preferable technique for fabricating tungsten coated graphite tiles to be used as tokamak first wall and target components. These coated tiles are more favourable compared to pure tungsten due to their light weight and easier machining. A system has been designed, fabricated and installed at SVITS, Indore for producing tungsten coated graphite tiles using Plasma Enhanced Chemical Vapor Deposition (PE-CVD) technique for Fusion plasma applications. The system contains a vacuum chamber, a turbo-molecular pump, two electrodes, vacuum gauges, mass analyzer, mass flow controllers and a RF power supply for producing the plasma using hydrogen gas. The graphite tiles will be put on one of the electrodes and WF6 gas will be inserted in a controlled manner in the hydrogen plasma to achieve the tungsten-coating with WF6 dissociation. The system is integrated at SVITS, Indore and a vacuum of the order of 3*10-6 is achieved and glow discharge plasma has been created to test all the sub-systems. The system design with all

  17. Gentamicin coating of plasma chemical oxidized titanium alloy prevents implant-related osteomyelitis in rats.

    Science.gov (United States)

    Diefenbeck, M; Schrader, C; Gras, F; Mückley, T; Schmidt, J; Zankovych, S; Bossert, J; Jandt, K D; Völpel, A; Sigusch, B W; Schubert, H; Bischoff, S; Pfister, W; Edel, B; Faucon, M; Finger, U

    2016-09-01

    Implant related infection is one of the most feared and devastating complication associated with the use of orthopaedic implant devices. Development of anti-infective surfaces is the main strategy to prevent implant contamination, biofilm formation and implant related osteomyelitis. A second concern in orthopaedics is insufficient osseointegration of uncemented implant devices. Recently, we reported on a macroporous titanium-oxide surface (bioactive TiOB) which increases osseointegration and implant fixation. To combine enhanced osseointegration and antibacterial function, the TiOB surfaces were, in addition, modified with a gentamicin coating. A rat osteomyelitis model with bilateral placement of titanium alloy implants was employed to analyse the prophylactic effect of gentamicin-sodiumdodecylsulfate (SDS) and gentamicin-tannic acid coatings in vivo. 20 rats were randomly assigned to four groups: (A) titanium alloy; PBS inoculum (negative control), (B) titanium alloy, Staphylococcus aureus inoculum (positive control), (C) bioactive TiOB with gentamicin-SDS and (D) bioactive TiOB plus gentamicin-tannic acid coating. Contamination of implants, bacterial load of bone powder and radiographic as well as histological signs of implant-related osteomyelitis were evaluated after four weeks. Gentamicin-SDS coating prevented implant contamination in 10 of 10 tibiae and gentamicin-tannic acid coating in 9 of 10 tibiae (infection prophylaxis rate 100% and 90% of cases, respectively). In Group (D) one implant showed colonisation of bacteria (swab of entry point and roll-out test positive for S. aureus). The interobserver reliability showed no difference in the histologic and radiographic osteomyelitis scores. In both gentamicin coated groups, a significant reduction of the histological osteomyelitis score (geometric mean values: C = 0.111 ± 0.023; D = 0.056 ± 0.006) compared to the positive control group (B: 0.244 ± 0.015; p osteomyelitis scores confirmed these

  18. Gentamicin coating of plasma chemical oxidized titanium alloy prevents implant-related osteomyelitis in rats.

    Science.gov (United States)

    Diefenbeck, M; Schrader, C; Gras, F; Mückley, T; Schmidt, J; Zankovych, S; Bossert, J; Jandt, K D; Völpel, A; Sigusch, B W; Schubert, H; Bischoff, S; Pfister, W; Edel, B; Faucon, M; Finger, U

    2016-09-01

    Implant related infection is one of the most feared and devastating complication associated with the use of orthopaedic implant devices. Development of anti-infective surfaces is the main strategy to prevent implant contamination, biofilm formation and implant related osteomyelitis. A second concern in orthopaedics is insufficient osseointegration of uncemented implant devices. Recently, we reported on a macroporous titanium-oxide surface (bioactive TiOB) which increases osseointegration and implant fixation. To combine enhanced osseointegration and antibacterial function, the TiOB surfaces were, in addition, modified with a gentamicin coating. A rat osteomyelitis model with bilateral placement of titanium alloy implants was employed to analyse the prophylactic effect of gentamicin-sodiumdodecylsulfate (SDS) and gentamicin-tannic acid coatings in vivo. 20 rats were randomly assigned to four groups: (A) titanium alloy; PBS inoculum (negative control), (B) titanium alloy, Staphylococcus aureus inoculum (positive control), (C) bioactive TiOB with gentamicin-SDS and (D) bioactive TiOB plus gentamicin-tannic acid coating. Contamination of implants, bacterial load of bone powder and radiographic as well as histological signs of implant-related osteomyelitis were evaluated after four weeks. Gentamicin-SDS coating prevented implant contamination in 10 of 10 tibiae and gentamicin-tannic acid coating in 9 of 10 tibiae (infection prophylaxis rate 100% and 90% of cases, respectively). In Group (D) one implant showed colonisation of bacteria (swab of entry point and roll-out test positive for S. aureus). The interobserver reliability showed no difference in the histologic and radiographic osteomyelitis scores. In both gentamicin coated groups, a significant reduction of the histological osteomyelitis score (geometric mean values: C = 0.111 ± 0.023; D = 0.056 ± 0.006) compared to the positive control group (B: 0.244 ± 0.015; p histological findings.

  19. Chemical compatibility of TRISO coated CHTR fuel with Pb-Bi eutectic alloy coolant

    International Nuclear Information System (INIS)

    In the present scenario, nuclear energy is inevitable to fulfil the energy demand of future era. Compact High Temperature Reactor (CHTR) is a small portable reactor which is designed to operate at 950°C and can supply electricity in the outlying area where normal large core reactor operation is almost impossible. TRISO coated uranium dioxide (UO2) microspheres are preferred fuel for CHTR. There are four coatings around the UO2 microsphere. From inside they are low density porous carbon layer known as buffer layer, high density inner pyrolytic carbon (IPyC) layer, silicon carbide (SiC) layer, high density outer pyrolytic carbon (OPyC) layer

  20. The Surface Coat of Plant-Parasitic Nematodes: Chemical Composition, Origin, and Biological Role—A Review

    OpenAIRE

    Spiegel, Y.; McClure, M. A.

    1995-01-01

    Chemical composition, origin, and biological role of the surface coat (SC) of plant-parasitic nematodes are described and compared with those of animal-parasitic and free-living nematodes. The SC of the plant-parasitic nematodes is 5-30 nm thick and is characterized by a net negative charge. It consists, at least in part, of glycoproteins and proteins with various molecular weights, depending upon the nematode species. The lability of its components and the binding of human red blood cells to...

  1. Nano-hydroxyapatite colloid suspension coated on chemically modified porous silicon by cathodic bias: a suitable surface for cell culture

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Alejandra [Escuela de Quimica, Universidad de Costa Rica, 2060 (Costa Rica); Centro de Electroquimica y Energia Quimica de la Universidad de Costa Rica (CELEQ), Universidad de Costa Rica, 2060 (Costa Rica); Gonzalez, Jerson [Escuela de Quimica, Universidad de Costa Rica, 2060 (Costa Rica); Garcia-Pineres, Alfonso [Escuela de Quimica, Universidad de Costa Rica, 2060 (Costa Rica); Centro de Investigacion en Biologia Celular y Molecular (CIBCM), Universidad de Costa Rica, 2060 (Costa Rica); Montero, Mavis L. [Escuela de Quimica, Universidad de Costa Rica, 2060 (Costa Rica); Centro de Electroquimica y Energia Quimica de la Universidad de Costa Rica (CELEQ), Universidad de Costa Rica, 2060 (Costa Rica); Centro de Ciencia e Ingenieria en Materiales (CICIMA), Universidad de Costa Rica, 2060 (Costa Rica)

    2011-06-15

    The properties of porous silicon make it an interesting material for biological applications. However, porous silicon is not an appropriate surface for cell growth. Surface modification is an alternative that could afford a bioactive material. In this work, we report a method to yield materials by modification of the porous silicon surface with hydroxyapatite of nanometric dimensions, produced using an electrochemical process and coated on macroporous silicon substrates by cathodic bias. The chemical nature of the calcium phosphate deposited on the substrates after the experimental process and the amount of cell growth on these surfaces were characterized. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Breaking seed coat dormancy with physical and chemical methods in tamarind (Tamarindus indica L.) seeds

    Science.gov (United States)

    Tamarind (Tamarindus indica L.) is an important tree crop in Africa and Asia. It is primarily propagated by grafting, which involves the generation of rootstock material. Tamarind seeds have an impermeable seed coat and need scarification for improved germination. In this study, tamarind seeds colle...

  3. Physico-chemical and antimicrobial properties of co-sputtered Ag-Au/PTFE nanocomposite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Zaporojtchenko, V [Chair for Multicomponent Materials, Technische Fakultaet der CAU, Kaiserstrasse 2, D-24143 Kiel (Germany); Podschun, R [Institute for Infection Medicine, University Hospital SH, Campus Kiel (Germany); Schuermann, U [Chair for Multicomponent Materials, Technische Fakultaet der CAU, Kaiserstrasse 2, D-24143 Kiel (Germany); Kulkarni, A [Chair for Multicomponent Materials, Technische Fakultaet der CAU, Kaiserstrasse 2, D-24143 Kiel (Germany); Faupel, F [Chair for Multicomponent Materials, Technische Fakultaet der CAU, Kaiserstrasse 2, D-24143 Kiel (Germany)

    2006-10-14

    In this work, we used co-sputtering of noble metals together with polytetrafluorethylene (PTFE) as a method for producing antibacterial metal/polymer nanocomposite coatings, where the precious metals are only incorporated in a thin surface layer. Moreover, they are finely dispersed as nanoparticles, thus saving additional material and providing a very large effective surface for metal ion release. Nanocomposite films with thickness between 100 and 300 nm were prepared with a wide range of metal filling between 10 and 40%. The antimicrobial effect of the nanocomposite coatings was evaluated by means of two different assays. The bactericidal activity due to silver release from the surface was determined by a modification of conventional disc diffusion methods. Inhibition of bacterial growth on the coated surface was investigated through a modified proliferation assay. Staphylococcus aureus and S. epidermidis were used as test bacteria, as these species commonly cause infections associated with medical polymer devices. The antibacterial efficiency of the coatings against different bacteria was demonstrated at extremely small noble metal consumption: Au: {approx}1 mg m{sup -2} and Ag: {approx}0.1 g m{sup -2}. The maximum ability for having an antibacterial effect was shown by the Ag-Au/PTFE nanocomposite, followed by the Ag/PTFE nanocomposite.

  4. Chemical, biochemical, and microbiological aspects of chitosan quaternary salt as active coating on sliced apples

    Directory of Open Access Journals (Sweden)

    Douglas de Britto

    2012-09-01

    Full Text Available The biocompatibility of chitosan and chitosan quaternary salt coatings was evaluated for use as edible coatings for sliced apple. Measurement of water loss, color change, and fungal growth appearance were monitored as a function of time. A significant brownish effect was observed on chitosan coated slices, varying greatly from L* = 76.5 and Hue angle = 95.9° (t = 0 to L* = 45.3 and Hue angle = 69.8° (t = 3 days, whilst for TMC coated samples the variation was considerable lower (L* = 74.1; Hue angle = 95.0° to (L* = 67.0; Hue angle = 83.8° within the same period. The hydrosoluble derivative N,N,N-trimethylchitosan demonstrated good antifungal activity against P. expansum although highly dependent on the polymer properties such as degree of quaternization. The most efficient formulation was that prepared from derivative having a degree of quaternization of 45%, high solubility, and high viscosity. This formulation restrained fungus spreading up to 30%, while for the control it reached almost 80% of the total assessed surfaces during 7 days of storage.

  5. Conformal coating of Ni(OH)2 nanoflakes on carbon fibers by chemical bath deposition for efficient supercapacitor electrodes

    KAUST Repository

    Alhebshi, Nuha

    2013-01-01

    A novel supercapacitor electrode structure has been developed in which a uniform and conformal coating of nanostructured Ni(OH)2 flakes on carbon microfibers is deposited in situ by a simple chemical bath deposition process at room temperature. The microfibers conformally coated with Ni(OH) 2 nanoflakes exhibit five times higher specific capacitance compared to planar (non-conformal) Ni(OH)2 nanoflake electrodes prepared by drop casting of Ni(OH)2 powder on the carbon microfibers (1416 F g-1vs. 275 F g-1). This improvement in supercapacitor performance can be ascribed to the preservation of the three-dimensional structure of the current collector, which is a fibrous carbon fabric, even after the conformal coating of Ni(OH)2 nanoflakes. The 3-D network morphology of the fibrous carbon fabric leads to more efficient electrolyte penetration into the conformal electrode, allowing the ions to have greater access to active reaction sites. Cyclic stability testing of the conformal and planar Ni(OH)2 nanoflake electrodes, respectively, reveals 34% and 62% drop in specific capacitance after 10 000 cycles. The present study demonstrates the crucial effect that electrolyte penetration plays in determining the pseudocapacitive properties of the supercapacitor electrodes. © 2013 The Royal Society of Chemistry.

  6. Deposition and characterization of diamond-like nanocomposite coatings grown by plasma enhanced chemical vapour deposition over different substrate materials

    Indian Academy of Sciences (India)

    Awadesh Kr Mallik; Nanadadulal Dandapat; Prajit Ghosh; Utpal Ganguly; Sukhendu Jana; Sayan Das; Kaustav Guha; Garfield Rebello; Samir Kumar Lahiri; Someswar Datta

    2013-04-01

    Diamond-like nanocomposite (DLN) coatings have been deposited over different substrates used for biomedical applications by plasma-enhanced chemical vapour deposition (PECVD). DLN has an interconnecting network of amorphous hydrogenated carbon and quartz-like oxygenated silicon. Raman spectroscopy, Fourier transform–infra red (FT–IR) spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD) have been used for structural characterization. Typical DLN growth rate is about 1 m/h, measured by stylus profilometer. Due to the presence of quartz-like Si:O in the structure, it is found to have very good adhesive property with all the substrates. The adhesion strength found to be as high as 0.6 N on SS 316 L steel substrates by scratch testing method. The Young’s modulus and hardness have found to be 132 GPa and 14.4 GPa, respectively. DLN coatings have wear factor in the order of 1 × 10-7 mm3/N-m. This coating has found to be compatible with all important biomedical substrate materials and has successfully been deposited over Co–Cr alloy based knee implant of complex shape.

  7. Changes in chemical composition of frozen coated fish products during deep-frying.

    Science.gov (United States)

    Pérez-Palacios, Trinidad; Petisca, Catarina; Casal, Susana; Ferreira, Isabel M P L V O

    2014-03-01

    This work evaluates the influence of deep-frying coated fish products on total fat, fatty acid (FA) and amino acid profile, and on the formation of volatile compounds, with special attention on furan and its derivatives due to their potential harmful characteristics. As expected, deep-frying in sunflower oil increased linoleic acid content, but total fat amount increased only by 2% on a dry basis. Eicosapentanoic and docosahexanoic acids were preserved while γ- and α-linoleic acids were oxidised. Deep-frying also induces proteolysis, releasing free AA, and the formation of volatile compounds, particularly aldehydes and ketones arising from polyunsaturated FA. In addition, high quantities of furanic compounds, particularly furan and furfuryl alcohol, are generated during deep-frying coated fish. The breaded crust formed could contribute simultaneously for the low uptake of fat, preservation of long chain n-3 FA, and for the high amounts of furanic compounds formed during the deep-frying process.

  8. Project W-314 Polyurea Special Protective Coating (SPC) Test Report Chemical Compatibility and Physical Characteristics Testing

    International Nuclear Information System (INIS)

    This Engineering Test report outlines the results obtained from testing polyurea on its decon factor, tank waste compatibility, and adhesion strength when subjected to a high level of gamma radiation. This report is used in conjunction with RPP-7187 Project W-314 Pit Coatings Repair Requirements Analysis, to document the fact polyurea meets the project W-314 requirements contained in HNF-SD-W314-PDS-005 and is therefore an acceptable SPC for use in W-314 pit refurbishments

  9. A Novel Strategy for Preparation of Si-HA Coatings on C/C Composites by Chemical Liquid Vaporization Deposition/Hydrothermal Treatments

    Science.gov (United States)

    Xin-Bo, Xiong; Xin-Ye, Ni; Ya-Yun, Li; Cen-Cen, Chu; Ji-Zhao, Zou; Xie-Rong, Zeng

    2016-08-01

    A novel strategy for the preparation of Si-doped hydroxyapatite (Si-HA) coatings on H2O2-treated carbon/carbon composites (C/C) was developed. HA coating was prepared on C/C through chemical liquid vaporization deposition (CLVD)/hydrothermal treatment. HA coating was immersed in an H2SiO3 solution at an autoclave at 413 K for transformation into Si-HA coating. The effects of H2SiO3 mass contents on the phase, morphology, and composition of the Si-HA coatings were studied through SEM, EDS,XRD, and FTIR. Their bonding performance to C/C was measured through a scratch test. Under the optimal content condition, the in vitro skull osteoblast response behaviors of the Si-HA coating were evaluated. Results showed that SiO32‑ could enter into the HA lattice and occupy the PO43‑ sites. Doped SiO32‑ significantly improved the bonding performance of the HA coating to C/C in comparison with the untreated HA. The adhesive strength of the coatings initially increased and then decreased with increasing H2SiO3 content. Meanwhile, the cohesive strength of the Si-HA coatings was almost nearly identical. The Si-HA coating achieved at a content of 90% H2SiO3 exhibited the best bonding performance, and its osteoblast compatibility in vitro was superior to that of the untreated HA coating on C/C through CLVD/hydrothermal treatment.

  10. A Novel Strategy for Preparation of Si-HA Coatings on C/C Composites by Chemical Liquid Vaporization Deposition/Hydrothermal Treatments.

    Science.gov (United States)

    Xin-Bo, Xiong; Xin-Ye, Ni; Ya-Yun, Li; Cen-Cen, Chu; Ji-Zhao, Zou; Xie-Rong, Zeng

    2016-08-05

    A novel strategy for the preparation of Si-doped hydroxyapatite (Si-HA) coatings on H2O2-treated carbon/carbon composites (C/C) was developed. HA coating was prepared on C/C through chemical liquid vaporization deposition (CLVD)/hydrothermal treatment. HA coating was immersed in an H2SiO3 solution at an autoclave at 413 K for transformation into Si-HA coating. The effects of H2SiO3 mass contents on the phase, morphology, and composition of the Si-HA coatings were studied through SEM, EDS,XRD, and FTIR. Their bonding performance to C/C was measured through a scratch test. Under the optimal content condition, the in vitro skull osteoblast response behaviors of the Si-HA coating were evaluated. Results showed that SiO3(2-) could enter into the HA lattice and occupy the PO4(3-) sites. Doped SiO3(2-) significantly improved the bonding performance of the HA coating to C/C in comparison with the untreated HA. The adhesive strength of the coatings initially increased and then decreased with increasing H2SiO3 content. Meanwhile, the cohesive strength of the Si-HA coatings was almost nearly identical. The Si-HA coating achieved at a content of 90% H2SiO3 exhibited the best bonding performance, and its osteoblast compatibility in vitro was superior to that of the untreated HA coating on C/C through CLVD/hydrothermal treatment.

  11. In Vitro Corrosion and Cytocompatibility of ZK60 Magnesium Alloy Coated with Hydroxyapatite by a Simple Chemical Conversion Process for Orthopedic Applications

    Directory of Open Access Journals (Sweden)

    Bing Wang

    2013-12-01

    Full Text Available Magnesium and its alloys—a new class of degradable metallic biomaterials—are being increasingly investigated as a promising alternative for medical implant and device applications due to their advantageous mechanical and biological properties. However, the high corrosion rate in physiological environments prevents the clinical application of Mg-based materials. Therefore, the objective of this study was to develop a hydroxyapatite (HA coating on ZK60 magnesium alloy substrates to mediate the rapid degradation of Mg while improving its cytocompatibility for orthopedic applications. A simple chemical conversion process was applied to prepare HA coating on ZK60 magnesium alloy. Surface morphology, elemental compositions, and crystal structures were characterized using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction, respectively. The corrosion properties of samples were investigated by immersion test and electrochemical test. Murine fibroblast L-929 cells were harvested and cultured with coated and non-coated ZK60 samples to determine cytocompatibility. The degradation results suggested that the HA coatings decreased the degradation of ZK60 alloy. No significant deterioration in compression strength was observed for all the uncoated and coated samples after 2 and 4 weeks’ immersion in simulated body fluid (SBF. Cytotoxicity test indicated that the coatings, especially HA coating, improved cytocompatibility of ZK60 alloy for L929 cells.

  12. Sensory and chemical stability in coated peanuts with the addition of essential oils and synthetic antioxidants

    Directory of Open Access Journals (Sweden)

    Olmedo, R. H.

    2012-03-01

    Full Text Available The objective of this work was to evaluate the antioxidant effect of essential oils on the oxidative stability of coated peanuts. Untreated coated peanuts (CP and treated coated peanuts with the addition of rosemary (CP-R, oregano (CP-O and laurel (CP-L essential oils and BHT (CPBHT were prepared. Peroxide values (PV and p-anisidine values (AV and the intensity ratings of sensory attributes by descriptive analysis were measured during 112 days of storage at room temperature (23°C. CP-BHT exhibited the lowest PV and AV increase. CP-R, CP-O and CP-L showed lower rates of increase in PV and AV than CP. The oxidized and cardboard flavor intensity ratings increased much more in CP during storage than the other studied products. CPBHT also showed the lowest increase in the intensity ratings of these sensory attributes. Three essential oils, namely, laurel, oregano and rosemary showed antioxidant activity and increased the shelf life of coated peanuts.

    El objetivo de este trabajo fue evaluar el efecto antioxidante de aceites esenciales sobre la estabilidad oxidativa en maní recubiertos. Se prepararon maníes recubiertos sin agregados (CP, y con el agregado de aceites esenciales de romero (CP-R, orégano (CP-O y laurel (CP-L y BHT (CPBHT. Se midieron, durante 112 días de almacenamiento, los valores de peróxidos (PV y p-anisidina (AV, y las intensidades de atributos sensoriales mediante análisis descriptivo. CP-BHT presentó el menor valor de PV y AV. CP-R, CP-O y CP-L tuvieron mayor PV y AV respecto a CP. Los valores de intensidad del sabor oxidado y cartón tuvieron un mayor incremento en CP durante el almacenamiento con respecto a los otros productos estudiados. La muestra CP-BHT también mostró los menores valores de intensidad de estos atributos sensoriales. Los aceites esenciales de laurel, orégano y romero presentaron actividad antioxidante e incrementaron la vida útil del maní recubierto.

  13. Polyethylene Maleate Copolyesters as Coating Materials for Piezoelectric Quartz Crystal-based Chemical Sensors

    Directory of Open Access Journals (Sweden)

    D. C. Gupta

    2005-10-01

    Full Text Available Polyethylene maleate (PEM was synthesised by direct polycondensation of maleic anhydride and ethylene glycol in toluene under reflux usingp-toluene sulphonic acid as a catalyst. Structure of PEM was further modified by varying nature of diols and acid components, chain length of glycols, incorporation of aromatic and fluorine groups in the chain. Formation of PEM was monitored by gas chromatography. The parameters like degree of polymerisation, number average molecular weight (Mn, and weight average molecular weight (Mw were calculated from the extent of reaction and stoichiometric ratio of the reactants. The number average molecular weight was also determined using Knauer vapour pressure osmometer. Cohesive energy, volume, and solubility parameters of PEM-based copolyesters were calculated by group contribution method. These PEM-based copolyesters’ have been evaluated as sorbent-coating materials for the detection of organ0 phosphorus(OPcompo using dimethylmethylphosphonate (DMMP as model compound and piezoelectric crystal detector. PEMbisphenol A is found to be the most sensitive and potential coating material for the detection of OP compounds using piezoelectric crystal detector. Potential PEM-based copolyesters have been characterised by viscosity, infrared spectroscopy, NMR spectroscopy, Mn and thermal stability.

  14. The effect of chemically coated nanofiber reinforcement on biopolymer based nanocomposites

    Directory of Open Access Journals (Sweden)

    Mohini Sain

    2007-01-01

    Full Text Available The aim of this work was to explore how various surface treatments would change the dispersion component of surface energy and acid-base character of hemp nanofibers, using inverse gas chromatography (IGC, and to investigate the effect of the incorporation of these modified nanofibers into a biopolymer matrix on the properties of their nano-composites. Bio-nanocomposite materials were prepared from poly (lactic acid (PLA and polyhydroxybutyrate (PHB as the matrix, and the cellulose nanofibers extracted from hemp fiber by chemo-mechanical treatments. Cellulose fibrils have a high density of –OH groups on the surface, which have a tendency to form hydrogen bonds with adjacent fibrils, reducing interaction with the surrounding matrix. It is necessary to reduce the entanglement of the fibrils and improve their dispersion in the matrix by surface modification of fibers without deteriorating their reinforcing capability. The IGC results indicated that styrene maleic anhydride coated and ethylene-acrylic acid coated fibers improved their potential to interact with both acidic and basic resins. From transmission electron microscopy (TEM, it was shown that the nanofibers were partially dispersed in the polymer matrix. The mechanical properties of the nanocomposites were lower than those predicted by theoretical calculations for both nanofiber-reinforced biopolymers.

  15. Hybrid Physical Chemical Vapor Deposition of Superconducting Magnesium Diboride Coatings for Large Scale Radio Frequency Cavities

    Science.gov (United States)

    Lee, Namhoon; Withanage, Wenura; Tan, Teng; Wolak, Matthaeus; Xi, Xiaoxing

    2016-03-01

    Magnesium diboride (MgB2) is considered to be a great candidate for next generation superconducting radio frequency (SRF) cavities due to its higher critical temperature Tc (40 K) and increased thermodynamic critical field Hc compared to other conventional superconductors. These properties significantly reduce the BCS surface resistance (RsBCS)and residual resistance (Rres) according to theoretical studies and suggest the possibility of an enhanced accelerating field (Eacc) . We have investigated the possibility of coating the inner surface of a 3 GHz SRF cavity with MgB2 by using a hybrid physical-vapor deposition (HPCVD) system which was modified for this purpose. To simulate a real 3 GHz SRF cavity, a stainless steel mock cavity has been employed for the study. The film quality was characterized on small substrates that were placed at selected locations within the cavity. MgB2 films on stainless steel foils, niobium pieces and SiC substrates showed transition temperatures of above 36 K. Dielectric resonance measurements resulted in promising Q values as obtained for the MgB2 films grown on the various substrates. By employing the HPCVD technique, a uniform film was achieved across the cavity interior, demonstrating the feasibility of HPCVD for MgB2 coatings for SRF cavities.

  16. Preparation of conversion coating on Ti-6Al-4V alloy in mixed solution of phytic acid and ammonium fluoride through chemical modification

    Science.gov (United States)

    Li, Lanlan; He, Jian; Yang, Xu

    2016-05-01

    Conversion coatings on Ti-6Al-4V alloy was prepared through chemical modification in phytic acid and ammonium fluoride mixed solution. The influences of pH, time and the composition of solution on the microstructure of alloy surface were investigated. Scanning electron microscopy was used to observe the microstructure. The chemical composition of alloy surface before and after modification was investigated by energy dispersive X-ray spectroscopy. The results indicated that a conversion coating could be formed on the Ti-6Al-4V alloy in a mixed solution of phytic acid and ammonium fluoride, the growth and microstructure of the conversion coatings were critically dependent on the pH, time and concentration of phytic acid and ammonium fluoride. In 100 mg/ml phytic acid containing 125 mg/ml ammonium fluoride solution with a pH of 6, a compact conversion coating with the thickness of about 4.7 μm formed after 30 min immersion on Ti-6Al-4V alloy surface. The preliminary evaluation of bioactivity of conversion coating was performed by in vitro cell experiments. The results showed that this chemical modification method is a promising surface modification technique for Ti-6Al-4V alloy inplants.

  17. Super-Hydrophobic and Oloephobic Crystalline Coatings by Initiated Chemical Vapor Deposition

    OpenAIRE

    Coclite, Anna Maria; Shi, Yujun; Gleason, Karen K.

    2013-01-01

    Preferred crystallographic orientation (texture) in thin films frequently has a strong effect on the properties of the materials and it is important for stable surface properties. Organized molecular films of poly-perfluorodecylacrylate p(PFDA) were deposited by initiated Chemical Vapor Deposition (iCVD). The high tendency of p(PFDA) to crystallize has been fully retained in the polymers prepared by iCVD. The degree of crystallinity and the preferred orientation of the perfluoro side chains, ...

  18. Oxygen Barrier Coating Deposited by Novel Plasma-enhanced Chemical Vapor Deposition

    DEFF Research Database (Denmark)

    Jiang, Juan; Benter, M.; Taboryski, Rafael Jozef;

    2010-01-01

    We report the use of a novel plasma-enhanced chemical vapor deposition chamber with coaxial electrode geometry for the SiOx deposition. This novel plasma setup exploits the diffusion of electrons through the inner most electrode to the interior samples space as the major energy source. This confi...... increased the barrier property of the modified low-density polyethylene, polyethylene terephthalate, and polylactide by 96.48%, 99.69%, and 99.25%, respectively....

  19. Quaternary hard nanocomposite TiCxNy/SiCN coatings prepared by plasma enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    Individual hard thin film materials such as TiN, SiN1.3, SiC and CNx exhibit attractive mechanical, tribological, optical and electronic properties related to their microstructure and chemical bonding. In the present work, we combine the characteristics of such materials, while systematically studying quaternary thin films prepared by plasma enhanced chemical vapor deposition (PECVD) from TiCl4/SiH4/N2/CH4 mixtures with different concentrations of CH4. Detailed structural and chemical characterizations using transmission electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and elastic recoil detection suggest formation of a TiCxNy/SiCN nanocomposite structure. Depth-sensing indentation, static indentation and curvature measurements, on samples prepared under optimal conditions, reveal a hardness of 55 GPa, reduced Young's modulus of 302 GPa, a compressive stress of 2.0 GPa, an elastic rebound of more than 80 %, H3/Er2 coefficient of 1.8 GPa and a high toughness. The friction coefficient and the wear rate, measured against diamond, are 0.13*10-6 and 12*10-6 mm3/Nm, respectively. We compare the properties of the present nanocomposite TiCxNy/SiCN coatings with the performance of PECVD films from our earlier studies: these include TiN/SiN1.3 nanocomposites and SiCN, for which we obtained a hardness of 45 and 33 GPa, and a reduced Young's modulus of 350 and 200 GPa, respectively

  20. Titania Coated Mica via Chemical Vapour Deposition, Post N-doped by Liquid Ammonia Treatment

    Science.gov (United States)

    Powell, Michael J.; Parkin, Ivan P.

    TiO2 films were successfully grown on synthetic mica powders via Chemical Vapor Deposition (CVD). The CVD rig is a cold-walled design that allows surface coverage of a powder to be successfully achieved. The TiO2 was produced by the reaction between TiCl4 and Ethyl Acetate. The powder produced could be successfully N-doped using post liquid ammonia treatment. The TiO2 powder produced could have potential applications in self-cleaning surfaces or antimicrobial paints.

  1. The Influence of Chemical Alloying on the High Temperature Wear Resistance of H-Free DLC Coatings

    NARCIS (Netherlands)

    Galvan, D.; Pei, Y.T.; Hosson, J.T.M. De; Cavaleiro, A.; Chandra, T; Tsuzaki, K; Militzer, M; Ravindran, C

    2007-01-01

    A commercial RF-sputtering deposition rig was employed to deposit H-free diamond-like carbon (DLC) coatings. The influence of alloying elements such as Ti and Si on the structure, mechanical and tribological properties of the coatings was investigated. The coating was observed in cross section and i

  2. Chemical pretreatments at surface of WC-6% Co for diamond coatings

    Institute of Scientific and Technical Information of China (English)

    刘沙; 易丹青; 余志明; 卢斌; 王建华

    2002-01-01

    The WC-6%Co(mass fraction) substrate surfaces were chemically pretreated with the two-step etching method, using Murakami reagent for 3~7min, and then an φ(HNO3)∶φ(HCl)=4∶1 solution for 1~15min. Diamond films were deposited on the substrates by a hot-filament chemical vapor deposition reactor. The results show that the Co content of the substrate surfaces can be reduced from 6% to 0.12% within the etching depth of 5~10μm, the surface roughness of the substrates is increased up to Ra=1.0μm, as well as the substrates hardness is decreased from HRA 89.5 to HRA 84.2 after the two-step etching. A slight preference towards {111} orientation can be observed from the XRD patterns and SEM micrograph of diamond film on WC-6%Co sample. The morphology of small rice-like ballas diamond was observed on the WC-6%Co substrates. A typical Raman spectrum with a sharp peak at 1332cm-1 for the diamond film indicates that the deposited films are good-quality polycrystalline diamond. The indentation testing shows that the adhesion between diamond film and the substrate after HF CVD deposition is good.

  3. CHEMICAL PRETREATMENTS OF THE SURFACE OF WC-15wt%Co WITH DIAMOND COATINGS

    Institute of Scientific and Technical Information of China (English)

    S. Liu; Z.M. Yu; D.Q. Yi; Y.X. Li

    2001-01-01

    Diamond films were deposited on the cemented carbide WC-15%Co substrates by a hot-filament chemical vapor deposition reactor. The substrate surfaces were chemically pretreated by the following two-step etching method: first using Murakami reagent for 1-3min, and second an HNO3:HCl=1:1 solution for 10-40min. It is indicated that the Co content of the substrate surfaces could be reduced from 15% to 0.81-6.04% within the etching depth of 5-10μm, the surface roughness of the substrates was increased up to Ra=1.0μm, and the substrates hardness was decreased from 89.0 HRA to 83.0HRA after the two-step etching. It is observed that the morphologies of the diamond films on the WC-15%Co substrates emerge in various shapes. The indentation testing shows that the good adhesion between diamond film and the substrate after HF CVD deposition could be obtained.

  4. Semi-quantitative chemical analysis of hard coatings by Raman micro-spectroscopy: the aluminium chromium nitride system as an example.

    Science.gov (United States)

    Kaindl, R; Sartory, B; Neidhardt, J; Franz, R; Reiter, A; Polcik, P; Tessadri, R; Mitterer, C

    2007-11-01

    A new method for chemical analyses of nitride-based hard coatings is presented. Raman band shifts in the spectra of Al(x)Cr(1-x)N coatings, deposited by physical vapour deposition from Al(x)Cr(1-x) targets with x (T,Al) = 0, 0.25, 0.50, 0.70 and 0.85, are calibrated using compositional data of the coatings derived by elastic recoil detection analysis (ERDA) and electron probe micro-analysis (EPMA). Inserting the composition-dependent Raman shift of a combinatorial acoustic-optic lattice mode into an empirically derived equation allows the determination of Al/Cr ratios of the coating with an accuracy of about +/-2%. Spot, line and area analyses of coated cemented carbide and cold work steel samples by using a computer-controlled, motorized x,y-stage are demonstrated and the most important errors influencing precision and accuracy are discussed. Figure Raman map of a coated cold-work steel sample. PMID:17932660

  5. Synthesis of BaTiO3 nanoparticles from TiO2-coated BaCO3 particles derived using a wet-chemical method

    OpenAIRE

    Yuuki Mochizuki; Naoto Tsubouchi; Katsuyasu Sugawara

    2014-01-01

    BaCO3 particles coated with amorphous TiO2 precursor are prepared by a wet chemical method to produce BaTiO3 nanoparticles at low temperatures. Subsequently, we investigate the formation behavior of BaTiO3 particles and the particle growth behavior when the precursor is subjected to heat treatment. The state of the amorphous TiO2 coating on the surface of BaCO3 particles depends on the concentration of NH4HCO3, and the optimum concentration is found to be in the range 0.5–1.0 M. Thermogravime...

  6. New sol–gel refractory coatings on chemically-bonded sand cores for foundry applications to improve casting surface quality

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Poulsen, T.; Stage, R.K.;

    2011-01-01

    Foundry refractory coatings protect bonded sand cores and moulds from producing defective castings during the casting process by providing a barrier between the core and the liquid metal. In this study, new sol–gel refractory coating on phenolic urethane cold box (PUCB) core was examined. The coa......Foundry refractory coatings protect bonded sand cores and moulds from producing defective castings during the casting process by providing a barrier between the core and the liquid metal. In this study, new sol–gel refractory coating on phenolic urethane cold box (PUCB) core was examined......–gel coated cores have better surface quality than those from uncoated cores and comparable surface quality with the commercial coatings. Therefore, the new sol–gel coating has a potential application in the foundry industry for improving the surface finish of castings thereby reducing the cost of fettling...... in the foundry industry since the raw materials and technology are easily affordable....

  7. Air-stable spin-coated naphthalocyanine transistors for enhanced chemical vapor detection.

    Science.gov (United States)

    Royer, James E; Zhang, Chengyi; Kummel, Andrew C; Trogler, William C

    2012-04-10

    Air-stable organic thin-film transistor (OTFT) sensors fabricated using spin-cast films of 5,9,14,18,23,27,32,36-octabutoxy-2,3-naphthalocyanine (OBNc) demonstrated improved chemical vapor sensitivity and selectivity relative to vacuum-deposited phthalocyanine (H(2)Pc) OTFTs. UV-vis spectroscopy data show that annealed spin-cast OBNc films exhibit a red-shift in the OBNc Q-band λ(max) which is generally diagnostic of improved π-orbital overlap in phthalocyanine ring systems. Annealed OBNc OTFTs have mobilities of 0.06 cm(2) V(-1) s(-1), low threshold voltages (|V(th)| < 1 V), and on/off ratios greater than 10(6). These air-stable device parameters are utilized for sensing modalities which enhance the sensitivity and selectivity of OBNc OTFTs relative to H(2)Pc OTFTs. While both sensors exhibit mobility decreases for all analytes, only OBNc OTFTs exhibit V(th) changes for highly polar/nonpolar analytes. The observed mobility decreases for both sensors are consistent with electron donation trends via hydrogen bonding by basic analytes. In contrast, V(th) changes for OBNc sensors appear to correlate with the analyte's octanol-water partition coefficient, consistent with polar molecules stabilizing charge in the organic semiconductor film. The analyte induced V(th) changes for OBNc OTFTs can be employed to develop selective multiparameter sensors which can sense analyte stabilized fixed charge in the film. PMID:22376236

  8. Solar Photocatalytic Removal of Chemical and Bacterial Pollutants from Water Using Pt/TiO2-Coated Ceramic Tiles

    Directory of Open Access Journals (Sweden)

    S. P. Devipriya

    2012-01-01

    Full Text Available Semiconductor photocatalysis has become an increasingly promising technology in environmental wastewater treatment. The present work reports a simple technique for the preparation of platinum-deposited TiO2 catalysts and its immobilization on ordinary ceramic tiles. The Pt/TiO2 is characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, energy dispersive X-ray spectroscopy (EDAX, and diffuse reflectance spectroscopy (DRS. Deposition of Pt on TiO2 extends the optical absorption of the latter to the visible region which makes it attractive for solar energy application. Optimum loading of Pt on TiO2 was found to be 0.5%. The Pt/TiO2 is coated on ceramic tiles and immobilized. This catalyst was found effective for the solar photocatalytic removal of chemical and bacterial pollutants from water. Once the parameters are optimized, the Pt/TiO2/tile can find application in swimming pools, hospitals, water theme parks, and even industries for the decontamination of water.

  9. P22 coat protein structures reveal a novel mechanism for capsid maturation: stability without auxiliary proteins or chemical crosslinks.

    Science.gov (United States)

    Parent, Kristin N; Khayat, Reza; Tu, Long H; Suhanovsky, Margaret M; Cortines, Juliana R; Teschke, Carolyn M; Johnson, John E; Baker, Timothy S

    2010-03-10

    Viral capsid assembly and stability in tailed, dsDNA phage and Herpesviridae are achieved by various means including chemical crosslinks (unique to HK97), or auxiliary proteins (lambda, T4, phi29, and herpesviruses). All these viruses have coat proteins (CP) with a conserved, HK97-like core structure. We used a combination of trypsin digestion, gold labeling, cryo-electron microscopy, 3D image reconstruction, and comparative modeling to derive two independent, pseudoatomic models of bacteriophage P22 CP: before and after maturation. P22 capsid stabilization results from intersubunit interactions among N-terminal helices and an extensive "P loop," which obviate the need for crosslinks or auxiliary proteins. P22 CP also has a telokin-like Ig domain that likely stabilizes the monomer fold so that assembly may proceed via individual subunit addition rather than via preformed capsomers as occurs in HK97. Hence, the P22 CP structure may be a paradigm for understanding how monomers assemble in viruses like phi29 and HSV-1.

  10. Latest innovations in large area web coating technology via plasma enhanced chemical vapor deposition source technology

    International Nuclear Information System (INIS)

    In this article, the authors discuss the latest results of our development of large area plasma enhanced chemical vapor deposition (PECVD) source technologies for flexible substrates. A significant challenge is the economical application of thin films for use as vapor barriers, transparent conductive oxides, and optical interference thin films. Here at General Plasma the authors have developed two innovative PECVD source technologies that provide an economical alternative to low temperature sputtering technologies and enable some thin film materials not accessible by sputtering. The Penning Discharge Plasma (PDP trade mark sign ) source is designed for high rate direct PECVD deposition on insulating, temperature sensitive web [J. Modocks, Proceedings of the Society of Vacuum Coaters, 2003 (unpublished), p. 187]. This technology has been utilized to deposit SiO2 and SiC:H for barrier applications [V. Shamamian et al. Proceedings of the Flexible Displays and Manufacturing Conferrence, 2006 (unpublished)]. The Plasma Beam Source (PBS trade mark sign ) is a remote plasma source that is more versatile for deposition on not only insulating flexible substrates but also conductive or rigid substrates for deposition of thin films that are sensitive to the high ion bombardment flux inherent to the PDP trade mark sign technology. The authors have developed PBS thin film processes in our laboratory for deposition of SiO2, SiC:O, SiN:C, SiN:H, ZnO, FeOx, and Al2O3. [M. A. George, Conference Proceedings of the Association of Industrial Metallizers, Coaters, and Laminators (AIMCAL), 2007 (unpublished)]. The authors discuss the design of the patented sources, plasma physics, and chemistry of the deposited thin films.

  11. Influence of bath PH value on microstructure and corrosion resistance of phosphate chemical conversion coating on sintered Nd-Fe-B permanent magnets

    Science.gov (United States)

    Ding, Xia; Xue, Long-fei; Wang, Xiu-chun; Ding, Kai-hong; Cui, Sheng-li; Sun, Yong-cong; Li, Mu-sen

    2016-10-01

    The effect of bath PH value on formation, microstructure and corrosion resistance of the phosphate chemical conversion (PCC) coatings as well as the effect on the magnetic property of the magnets is investigated in this paper. The results show that the coating mass and thickness increase with the decrease of the bath PH value. Scanning electron microscopy observation demonstrates that the PCC coatings are in a blocky structure with different grain size. Transmission electron microscope and X-ray diffractometer tests reveal the coatings are polycomponent and are mainly composed of neodymium phosphate hydrate and praseodymium phosphate hydrate. The electrochemical analysis and static immersion corrosion test show the corrosion resistance of the PCC coatings prepared at bath PH value of 0.52 is worst. Afterwards the corrosion resistance increases first and then decreases with the increasing of the bath PH values. The magnetic properties of all the samples with PCC treatment are decreased. The biggest loss is occurred when the bath PH value is 0.52. Taken together, the optimum PH range of 1.00-1.50 for the phosphate solution has been determined.

  12. Water vapor-controlled thermal plasma chemical vapor deposition of double-layered TiN/PSZ coatings on Si and WC-Co substrates

    International Nuclear Information System (INIS)

    Double-layer TiN/PSZ film coatings were deposited on Si wafers and WC-Co cutting tools from Ti-, Zr-, and Y-alkoxide solutions by thermal plasma chemical vapor deposition (CVD) containing water vapor. The partially stabilized zirconia (PSZ) layer was coated on a TiN film by oxidation of Zr- and Y-alkoxides with H2O supplied by both constant and step-wise methods. Double-layer TiN/PSZ coatings deposited on Si wafers and WC-Co by the two H2O supply methods were approximately 2 μm thick. TEM observation showed that the interface between the TiN and PSZ in the double-layer TiN/PSZ formed by the step-wise H2O supply is more adhesive than under constant H2O supply. Double-layer TiN/PSZ films coated on WC-Co substrates by the step-wise supply exhibited good crater wear resistance, comparable to a commercial double-layer TiN/Al2O3 coating by thermal CVD.

  13. Water vapor-controlled thermal plasma chemical vapor deposition of double-layered TiN/PSZ coatings on Si and WC-Co substrates

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Takanori [Graduate School of Engineering, Hokkaido University, West-8, North-13, Kita-ku, Sapporo 060-8628 (Japan); Shimada, Shiro, E-mail: shimashi@eng.hokudai.ac.jp [Graduate School of Engineering, Hokkaido University, West-8, North-13, Kita-ku, Sapporo 060-8628 (Japan); Kiyono, Hajime [Graduate School of Engineering, Hokkaido University, West-8, North-13, Kita-ku, Sapporo 060-8628 (Japan); Tsujino, Jiro [Research and Development Department, Hokkaido Electric Power Co. Ltd., 2-1, Tsuishikari, Ebetsu City 067-0033 (Japan); Yamazaki, Isao [Hokkaido Sumiden Precision Industries Ltd., 776 Naie, Sorachi-gun, Hokkaido 079-0304 (Japan)

    2010-08-25

    Double-layer TiN/PSZ film coatings were deposited on Si wafers and WC-Co cutting tools from Ti-, Zr-, and Y-alkoxide solutions by thermal plasma chemical vapor deposition (CVD) containing water vapor. The partially stabilized zirconia (PSZ) layer was coated on a TiN film by oxidation of Zr- and Y-alkoxides with H{sub 2}O supplied by both constant and step-wise methods. Double-layer TiN/PSZ coatings deposited on Si wafers and WC-Co by the two H{sub 2}O supply methods were approximately 2 {mu}m thick. TEM observation showed that the interface between the TiN and PSZ in the double-layer TiN/PSZ formed by the step-wise H{sub 2}O supply is more adhesive than under constant H{sub 2}O supply. Double-layer TiN/PSZ films coated on WC-Co substrates by the step-wise supply exhibited good crater wear resistance, comparable to a commercial double-layer TiN/Al{sub 2}O{sub 3} coating by thermal CVD.

  14. Use of antimicrobial films and edible coatings incorporating chemical and biological preservatives to control growth of Listeria monocytogenes on cold smoked salmon.

    Science.gov (United States)

    Neetoo, Hudaa; Mahomoodally, Fawzi

    2014-01-01

    The relatively high incidence of Listeria monocytogenes in cold smoked salmon (CSS) is of concern as it is a refrigerated processed food of extended durability (REPFED). The objectives of this study were to compare and optimize the antimicrobial effectiveness of films and coatings incorporating nisin (Nis) and sodium lactate (SL), sodium diacetate (SD), potassium sorbate (PS), and/or sodium benzoate (SB) in binary or ternary combinations on CSS. Surface treatments incorporating Nis (25000 IU/mL) in combination with PS (0.3%) and SB (0.1%) had the highest inhibitory activity, reducing the population of L. monocytogenes by a maximum of 3.3 log CFU/cm(2) (films) and 2.9 log CFU/cm(2) (coatings) relative to control samples after 10 days of storage at 21°C. During refrigerated storage, coatings were more effective in inhibiting growth of L. monocytogenes than their film counterparts. Cellulose-based coatings incorporating Nis, PS, and SB reduced the population of L. monocytogenes, and anaerobic and aerobic spoilage flora by a maximum of 4.2, 4.8, and 4.9 log CFU/cm(2), respectively, after 4 weeks of refrigerated storage. This study highlights the effectiveness of cellulose-based edible coatings incorporating generally regarded as safe (GRAS) natural and chemical antimicrobials to inhibit the development of L. monocytogenes and spoilage microflora thus enhancing the safety and quality of CSS. PMID:25089272

  15. Preparation of photocatalytic Fe 2O 3-TiO 2 coatings in one step by metal organic chemical vapor deposition

    Science.gov (United States)

    Zhang, Xingwang; Lei, Lecheng

    2008-02-01

    There are two major difficulties in the TiO 2 liquid-solid photocatalytic system: effective immobilization of the TiO 2 particles; and improving the catalytic activity under visible light. To simultaneously solve these two problems, Fe 2O 3-TiO 2 coatings supported on activated carbon fiber (ACF), have been prepared in one step by a convenient and efficient method—metal organic chemical vapor deposition (MOCVD). XRD results revealed that Fe 2O 3-TiO 2 coatings mainly composed of anatase TiO 2, α-Fe 2O 3 phases and little Fe 2Ti 3O 9. The pore structure of ACF was preserved well after loading with Fe 2O 3-TiO 2 coatings. UV-vis diffuse reflectance spectra showed a slight shift to longer wavelengths and an enhancement of the absorption in the visible region for Fe 2O 3-TiO 2 coatings, compared to the pure TiO 2 sample. A moderate Fe 2O 3-TiO 2 loading (13.7 wt%) was beneficial to mineralizing wastewater because the intermediates could be adsorbed onto the surface of photocatalyst following decomposition. The stable performance revealed that the Fe 2O 3-TiO 2 coatings were strongly adhered to the ACF surface, and the as prepared catalysts could be reused showing potential application for wastewater treatment.

  16. Use of Antimicrobial Films and Edible Coatings Incorporating Chemical and Biological Preservatives to Control Growth of Listeria monocytogenes on Cold Smoked Salmon

    Directory of Open Access Journals (Sweden)

    Hudaa Neetoo

    2014-01-01

    Full Text Available The relatively high incidence of Listeria monocytogenes in cold smoked salmon (CSS is of concern as it is a refrigerated processed food of extended durability (REPFED. The objectives of this study were to compare and optimize the antimicrobial effectiveness of films and coatings incorporating nisin (Nis and sodium lactate (SL, sodium diacetate (SD, potassium sorbate (PS, and/or sodium benzoate (SB in binary or ternary combinations on CSS. Surface treatments incorporating Nis (25000 IU/mL in combination with PS (0.3% and SB (0.1% had the highest inhibitory activity, reducing the population of L. monocytogenes by a maximum of 3.3 log CFU/cm2 (films and 2.9 log CFU/cm2 (coatings relative to control samples after 10 days of storage at 21°C. During refrigerated storage, coatings were more effective in inhibiting growth of L. monocytogenes than their film counterparts. Cellulose-based coatings incorporating Nis, PS, and SB reduced the population of L. monocytogenes, and anaerobic and aerobic spoilage flora by a maximum of 4.2, 4.8, and 4.9 log CFU/cm2, respectively, after 4 weeks of refrigerated storage. This study highlights the effectiveness of cellulose-based edible coatings incorporating generally regarded as safe (GRAS natural and chemical antimicrobials to inhibit the development of L. monocytogenes and spoilage microflora thus enhancing the safety and quality of CSS.

  17. Rapid mixing chemical oxidative polymerization: an easy route to prepare PANI coated small-diameter CNTs/PANI nanofibres composite thin film

    Indian Academy of Sciences (India)

    G Venkata Ramana; Balaji Padya; Vadali V S S Srikanth; P K Jain

    2014-05-01

    Composite thin film containing polyaniline (PANI) coated small diameter carbon nanotubes (SDCNTs)/PANI nanofibres (NFs) has been prepared using an easy in situ rapid mixing chemical oxidative polymerization method. SDCNTs thin film was obtained using thermal chemical vapour deposition method in a separate experiment, whilst PANI NFs are formed in situ during the synthesis of composite. In the composite, PANI coated SDCNTs are uniformly distributed among PANI NFs. The presence of SDCNTs during the composite synthesis does not influence the nucleation and growth of PANI NFs. Raman analysis shows a good interaction between PANI and SDCNTs. Room temperature d.c. electrical sheet resistance of SDCNTs/PANI NFs composite thin film surface is three orders lesser than that of PANI NFs thin film (PANI NFs have the same morphology as in the composite) synthesized using the same method but without the presence of SDCNTs.

  18. Effects of the chemical bonding on the optical and mechanical properties for germanium carbide films used as antireflection and protection coating of ZnS windows

    Science.gov (United States)

    Hu, Chaoquan; Zheng, Weitao; Tian, Hongwei; LeXu; Jiang, Qing

    2006-05-01

    Germanium carbide (Ge1-xCx) films have been prepared by RF reactive sputtering a pure Ge(111) target at different flow rate ratios of CH4/(CH4+Ar) in a CH4/Ar mixture discharge, and it has been found that the composition, chemical bonding, optical and mechanical properties of Ge1-xCx films are remarkably influenced by the flow rate ratio of CH4/(CH4+Ar). The effects of the chemical bonding on the optical and mechanical properties of the Ge1-xCx films have been explored. In addition, an antireflection Ge1-xCx double-layer coating deposited on both sides of the ZnS substrate wafer has been developed for application as an infrared window. It is shown that the transmittance in the wavelength region between 8 and 12 µm and the hardness of the ZnS substrate have been significantly improved by the double-layer coating.

  19. Physical and tribological properties of a-Si1-xCx:H coatings prepared by r.f. plama-assisted chemical vapour deposition

    International Nuclear Information System (INIS)

    A-Si1-xCx:H films deposited by r.f. plasma-assisted chemical vapour deposition were studied as a function of their composition. The friction and wear properties were investigated with the help of a conventional ball-on-disc apparatus. These results are correlated with chemical (Si/C atomic ratio) and structural (Raman and infrared spectroscopy) properties. The friction coefficient in a humid ambient atmosphere changes markedly with the carbon fraction and reaches a value as low as 0.05 for coatings with 70 to 90 at.% C. The carbon-rich films consist of diamond-like carbon with silicon. (orig.)

  20. Characterization of ceramic sol-gel coatings as an alternative chemical conversion treatment on commercial carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez-Crespo, M.A. [Instituto Politecnico Nacional, Grupo de Ingenieria en Procesamiento de Materiales CICATA-IPN, Unidad Altamira, km 14.5, Carretera Tampico-Puerto Industrial Altamira, C.P. 89600 Altamira, Tamps (Mexico)], E-mail: mdominguezc@ipn.mx; Garcia-Murillo, A.; Torres-Huerta, A.M.; Carrillo-Romo, F.J. [Instituto Politecnico Nacional, Grupo de Ingenieria en Procesamiento de Materiales CICATA-IPN, Unidad Altamira, km 14.5, Carretera Tampico-Puerto Industrial Altamira, C.P. 89600 Altamira, Tamps (Mexico); Onofre-Bustamante, E. [Universidad Nacional Autonoma de Mexico, Edificio D Facultad de Quimica, Departamento de Metalurgia, Ciudad Universitaria, C.P. 04510 Mexico D.F. (Mexico); Yanez-Zamora, C. [Alumna del postgrado en Tecnologia Avanzada del CICATA-IPN, Unidad Altamira IPN, km 14.5, Carretera Tampico-Puerto Industrial Altamira, C.P. 89600 Altamira, Tamps (Mexico)

    2009-04-01

    Sol-gel yttria-stabilized zirconia (YSZ) thin films were prepared on commercial carbon steel sheets by dip-coating technique followed by a low temperature heat treatment (473, 573, and 673 K for 1 h) in order to improve both corrosion properties and adhesion. For comparison, zirconia (ZrO{sub 2}) coatings have been also analyzed. Electrochemical techniques, Fourier Transform Infrared (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the anticorrosion behavior of the coatings in a 3.5 wt% NaCl solution. The adhesion with a polyester organic coating was evaluated by the pull-off technique. The typical thickness of the deposited layers ranged from 1 to 1.3 {mu}m depending on process parameters. The obtained results indicated that sol-gel ZrO{sub 2} and YSZ coatings without an organic coating can act as protective barriers against wet corrosion during the first hours, but they fail when the time exposure is longer than 1 day. However, when synthesized films were used as a pre-treatment and an organic coating was added (top-coated), the anticorrosive and adhesion properties were strongly affected by the temperature of the treatment, and an increase in both properties was observed at higher temperatures. The structural and morphological characteristics of the coating provide an explanation of the role of each film in the electrochemical behavior in this aggressive medium. Comparing both systems, YSZ displayed greater protective and adhesion values than exhibited for ZrO{sub 2} which can be correlated with the stabilization of the cubic phase.

  1. Characterization of ceramic sol-gel coatings as an alternative chemical conversion treatment on commercial carbon steel

    International Nuclear Information System (INIS)

    Sol-gel yttria-stabilized zirconia (YSZ) thin films were prepared on commercial carbon steel sheets by dip-coating technique followed by a low temperature heat treatment (473, 573, and 673 K for 1 h) in order to improve both corrosion properties and adhesion. For comparison, zirconia (ZrO2) coatings have been also analyzed. Electrochemical techniques, Fourier Transform Infrared (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the anticorrosion behavior of the coatings in a 3.5 wt% NaCl solution. The adhesion with a polyester organic coating was evaluated by the pull-off technique. The typical thickness of the deposited layers ranged from 1 to 1.3 μm depending on process parameters. The obtained results indicated that sol-gel ZrO2 and YSZ coatings without an organic coating can act as protective barriers against wet corrosion during the first hours, but they fail when the time exposure is longer than 1 day. However, when synthesized films were used as a pre-treatment and an organic coating was added (top-coated), the anticorrosive and adhesion properties were strongly affected by the temperature of the treatment, and an increase in both properties was observed at higher temperatures. The structural and morphological characteristics of the coating provide an explanation of the role of each film in the electrochemical behavior in this aggressive medium. Comparing both systems, YSZ displayed greater protective and adhesion values than exhibited for ZrO2 which can be correlated with the stabilization of the cubic phase

  2. Structural and chemical analysis of silica-doped β-TCP ceramic coatings on surgical grade 316L SS for possible biomedical application

    Directory of Open Access Journals (Sweden)

    Karuppasamy Prem Ananth

    2015-09-01

    Full Text Available We have developed a novel approach to introduce silica-doped β-tricalcium phosphate (Si-β-TCP on 316L SS substrates for enhanced biological properties. Doping of β-TCP with silica loadings ranging from 0 to 8 mol% was carried out using chemical precipitation method. Si-β-TCP powder was sintered at 800 °C followed by coating it on 316L SS substrate using electrophoretic deposition. The coated and uncoated samples were investigated by various characterization techniques such as X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, field emission scanning electron microscopy (FESEM and X-ray fluorescence spectroscopy (XRF. Biomineralization ability of the coatings was evaluated by immersing in simulated body fluid (SBF solution for different number of days such as 7, 14, 21 and 28 days. The results obtained in our study have shown that the apatite formation ability was high for the 8 mol% of Si-β-TCP. This will promote better biomineralization ability compared to the other coatings.

  3. The Synthesis of Anatase Nanoparticles and the Preparation of Photocatalytically Active Coatings Based on Wet Chemical Methods for Self-Cleaning Applications

    Directory of Open Access Journals (Sweden)

    Dejan Verhovšek

    2012-01-01

    Full Text Available We report on an improved sol-gel method for the production of highly photocatalytic titanium dioxide (TiO2 anatase nanoparticles which can provide appropriate control over the final characteristics of the nanoparticles, such as particle size, crystallinity, crystal structure, morphology, and also the degree of agglomeration. The synthesized anatase nanoparticles were characterized using various techniques, such as X-ray powder diffraction (XRD, scanning electron microscopy (SEM, and transmission electron microscopy (TEM, and were tested in coatings for self-cleaning glass and ceramic surfaces. The coatings were prepared using a soft chemistry route and are completely transparent to visible light and exhibit a high photocatalytic effect, which was determined by contact-angle measurements. Finally, it is worth mentioning that both the sol-gel synthesis method and the coating-preparation method are based on a wet chemical process, thus presenting no risk of handling the TiO2 anatase nanoparticles in their potentially hazardous powder form at any stage of our development. Low-price, easy-to-handle, and nontoxic materials were used. Therefore, our work represents an important contribution to the development of TiO2 anatase nanoparticle coatings that provide a high photocatalytic effect and can thus be used for numerous applications.

  4. A comparative physico-chemical study of chlorapatite and hydroxyapatite: from powders to plasma sprayed thin coatings

    OpenAIRE

    Demati, Imane; Grossin, David; Combes, Christèle; Parco, Maria; Braceras, Inigo; Rey, Christian

    2012-01-01

    International audience Due to their bioactivity and osteoconductivity, hydroxyapatite (HA) plasma sprayed coatings have been widely developed for orthopedic uses. However, the thermodynamic instability of HA leads frequently to a mixture of phases which limit the functional durability of the coating. This study investigates the plasma spraying of chlorapatite (ClA) powder, known to melt without decomposition, onto pure titanium substrates using a low energy plasma spray system (LEPS). Pure...

  5. Fiber Bragg distributed chemical sensor

    NARCIS (Netherlands)

    Boersma, A.; Cheng, L.K.; Jansen, T.H.

    2010-01-01

    A distributed chemical sensor is developed by coating multiple Bragg gratings in a fibre with chemical selective responsive coatings. The optical response of the coated grating is optimised and the recoat process is very reproducible.

  6. Progress towards all-chemical superconducting YBa{sub 2}Cu{sub 3}O{sub 7}-coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Obradors, X [Institut de Ciencia de Materials de Barcelona, CSIC Campus de la UAB, 08193 Bellaterra (Spain); Puig, T [Institut de Ciencia de Materials de Barcelona, CSIC Campus de la UAB, 08193 Bellaterra (Spain); Pomar, A [Institut de Ciencia de Materials de Barcelona, CSIC Campus de la UAB, 08193 Bellaterra (Spain)] (and others)

    2006-03-15

    Chemical solution deposition (CSD) has recently emerged as a very competitive technique for obtaining epitaxial films of high quality with controlled nanostructure. In particular, the all-CSD approach is considered to be one of the most promising approaches for cost-effective production of second-generation superconducting wires. The trifluoroacetate (TFA) route is a very versatile route for achieving epitaxial YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) layers with high critical currents. In this work, recent advances towards improvement of the performance of several conductor architectures based on the YBCO TFA process will be presented. We show that new improved anhydrous TFA precursors allow a significant shortening of the pyrolysis time ({approx}1.5 h), and we have increased the total film thickness in a single deposition using polymeric additives. On the other hand, further understanding of the YBCO nucleation and growth process has allowed us to obtain a controlled microstructure and high critical currents (J{sub c}{approx}4-5 MA cm{sup -2} and I{sub c}{approx}300 A cm{sup -1} width at 77 K). The growth conditions (CSD) and post-processing conditions (sputtering and CSD) for the underlying oxide cap and buffer layers (CeO{sub 2}, BaZrO{sub 3}, SrTiO{sub 3}, La{sub 2}Zr{sub 2}O{sub 7} (La,Sr)MnO{sub 3}) and of self-organized nanostructures (CeO{sub 2}, BaZrO{sub 3}) deposited by CSD have been investigated to obtain high-quality interfaces in multilayered systems. Different single-crystal or metallic substrates (YSZ-IBAD (yttrium stabilized zirconia-ion beam assisted deposition) and Ni-RABiT (rolling assisted biaxial texturing)) have been investigated and long ({approx}10 m) CSD biaxially textured buffers (CeO{sub 2}, La{sub 2}Zr{sub 2}O{sub 7}) have been grown on Ni-RABiT substrates using a reel-to-reel system. High-performance TFA-YBCO-coated conductors have been obtained on vacuum-based buffer layers (I{sub c}{approx}140 A cm{sup -1} width) and on CSD buffer layers

  7. Microstructure, physical and chemical properties of nanostructured (Ti–Hf–Zr–V–Nb)N coatings under different deposition conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pogrebnjak, A.D.; Yakushchenko, I.V. [Sumy State University, 2, Rymsky Korsakov Str., 40007 Sumy (Ukraine); Bagdasaryan, A.A., E-mail: artemsumdu@ukr.net [Sumy State University, 2, Rymsky Korsakov Str., 40007 Sumy (Ukraine); Bondar, O.V. [Sumy State University, 2, Rymsky Korsakov Str., 40007 Sumy (Ukraine); Krause-Rehberg, R. [Martin-Luther-University Halle-Wittenberg, Halle (Germany); Abadias, G.; Chartier, P. [Institut P' , University of Poitiers, Chasseneuil-Futuroscope (France); Oyoshi, K.; Takeda, Y. [National Institute for Material Science, Tsukuba (Japan); Beresnev, V.M. [Kharkiv National University, 21, Svobody Sq., 4, 61022 Kharkiv (Ukraine); Sobol, O.V. [National Technical University, Kharkiv Polytechnic Institute, Kharkiv (Ukraine)

    2014-10-15

    High-entropy alloy and nitride coatings (TiHfZrVNb)N were prepared by the cathodic-arc-vapor-deposition method under various deposition conditions. The composition, crystal structure, strain-stress state, profiles of defects and atoms in-depth and at surfaces of the (TiHfZrVNb)N coatings were characterized by EDS and SEM analysis, X-ray diffraction with “α-sin{sup 2}ψ” method of measurements and slow positron beam. The oxidation behavior of nitride films after annealing at 600 °C temperature was studied. The results indicate that nitride coatings show the face-centered cubic crystal structure. The redistributions of elements and defects, their arrangement (segregation) due to the thermally stimulated diffusion and termination of the spinodal segregation near the interfaces, around the grains and subgrains were found. The peak hardness and modulus of the nitride films were 44.3 and 384 GPa, respectively. The tribological properties of the (TiHfZrVNb)N coatings against AISI 1045 were evaluated by a ball-on-disc tribometer with a 3.0 N applied load. - Highlights: • (Ti–Hf–Zr–V–Nb)N coatings produced by CAVD exhibit enhanced strength. • The influence of deposition parameters on the defect structure in the coating was discussed. • Partial relaxation of compressive stress is observed after thermal annealing at 600 °C. • Coatings deposited on the steel substrate improve its tribological performance.

  8. Growth of ZnS-coated ZnO nanorod arrays on (1 0 0) silicon substrate by two-step chemical synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Kumarakuru, Haridas, E-mail: haridas.kumarakuru@nmmu.ac.za [Centre for High Resolution Transmission Electron Microscopy (CHRTEM), Department of Physics, P.O.Box 77000, Nelson Mandela Metropolitan University (NMMU), Port Elizabeth 6031 (South Africa); Urgessa, Zelalem N. [Department of Physics, Nelson Mandela Metropolitan University (NMMU), P.O. Box 77000, Port Elizabeth 6031 (South Africa); Olivier, Ezra J. [Centre for High Resolution Transmission Electron Microscopy (CHRTEM), Department of Physics, P.O.Box 77000, Nelson Mandela Metropolitan University (NMMU), Port Elizabeth 6031 (South Africa); Botha, Johannes R.; Venter, Andre [Department of Physics, Nelson Mandela Metropolitan University (NMMU), P.O. Box 77000, Port Elizabeth 6031 (South Africa); Neethling, Johannes H. [Centre for High Resolution Transmission Electron Microscopy (CHRTEM), Department of Physics, P.O.Box 77000, Nelson Mandela Metropolitan University (NMMU), Port Elizabeth 6031 (South Africa); Department of Physics, Nelson Mandela Metropolitan University (NMMU), P.O. Box 77000, Port Elizabeth 6031 (South Africa)

    2014-11-05

    Highlights: • ZnS coated ZnO nanorods were synthesized using a simple two-step chemical method. • The uniform ZnS coating exhibits a polycrystalline face centered cubic structure. • Initial ZnS deposit exhibits a partial epitaxial relationship with ZnO. • An ion-exchange reaction was deduced for this sulphidation process. • Detailed microscopy results are complemented by room temperature photoluminescence. - Abstract: In this study, ZnS coated ZnO nanorods were synthesized using a simple, cost effective two-step chemical method. A continuous coating of ZnS on a ZnO nanorod, having a uniform thickness, is demonstrated using high resolution transmission electron microscopy, electron energy loss spectroscopy and selected area diffraction (SAD). These core–shell structures can be produced at relatively low temperatures (75 °C) and within relatively short times (3 h). The ZnS coating exhibits a polycrystalline structure with a lattice parameter of 5.35 Å, which is 1.1% smaller than the unstrained cubic zinc-blende structure. The SAD pattern taken at the ZnO–ZnS interface exhibits a partial epitaxial relationship, where (1 0 –1 0) ZnO//(1 1 1) ZnS. Our detailed analysis shows that the ZnS shell comprises two different regions: a ZnS rich inner shell region is produced via the first sulphidation process, followed by a mixture of ZnO and ZnS in the outer shell region during the second treatment. From the detailed microscopy results a growth mechanism is proposed for each step of the sulphidation process. The results are complemented by room temperature photoluminescence spectroscopy. Strong emission from free excitons in ZnO is observed at 3.27 eV before ZnS coating, while a composite band peaking at 2.9 eV is measured after sulphidation. The origin of the latter will be discussed.

  9. Growth of ZnS-coated ZnO nanorod arrays on (1 0 0) silicon substrate by two-step chemical synthesis

    International Nuclear Information System (INIS)

    Highlights: • ZnS coated ZnO nanorods were synthesized using a simple two-step chemical method. • The uniform ZnS coating exhibits a polycrystalline face centered cubic structure. • Initial ZnS deposit exhibits a partial epitaxial relationship with ZnO. • An ion-exchange reaction was deduced for this sulphidation process. • Detailed microscopy results are complemented by room temperature photoluminescence. - Abstract: In this study, ZnS coated ZnO nanorods were synthesized using a simple, cost effective two-step chemical method. A continuous coating of ZnS on a ZnO nanorod, having a uniform thickness, is demonstrated using high resolution transmission electron microscopy, electron energy loss spectroscopy and selected area diffraction (SAD). These core–shell structures can be produced at relatively low temperatures (75 °C) and within relatively short times (3 h). The ZnS coating exhibits a polycrystalline structure with a lattice parameter of 5.35 Å, which is 1.1% smaller than the unstrained cubic zinc-blende structure. The SAD pattern taken at the ZnO–ZnS interface exhibits a partial epitaxial relationship, where (1 0 –1 0) ZnO//(1 1 1) ZnS. Our detailed analysis shows that the ZnS shell comprises two different regions: a ZnS rich inner shell region is produced via the first sulphidation process, followed by a mixture of ZnO and ZnS in the outer shell region during the second treatment. From the detailed microscopy results a growth mechanism is proposed for each step of the sulphidation process. The results are complemented by room temperature photoluminescence spectroscopy. Strong emission from free excitons in ZnO is observed at 3.27 eV before ZnS coating, while a composite band peaking at 2.9 eV is measured after sulphidation. The origin of the latter will be discussed

  10. Gas barrier properties of hydrogenated amorphous carbon films coated on polymers by surface-wave plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Gas barrier characteristics of hydrogenated amorphous carbon (a-C:H) thin films coated on polymer sheets using the large-area surface-wave plasma (SWP) were studied. With SWP in He and CH4 gas mixture, a-C:H films were deposited over about 100 mm in diameter on high density polyethylene or polyethylene terephthalate (PET) sheets at temperature less than 70 deg. C. Experimental results show that gas permeation in the case of a-C:H film coating on PET sheet was reduced by a factor of more than 150 (0.27 cm3/m2 day atm), compared with that before coating. Plasma characteristics of SWP, such as electron density and electron energy distribution functions, and other film characteristics measured with Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy and atomic force microscope are presented and discussed

  11. Chemical studies on the preparation of magnetic nanoparticles coated with glycine and its application for removal of heavy metals

    Directory of Open Access Journals (Sweden)

    Jawaher Alzaidi

    2016-06-01

    Full Text Available The aim of this study is the preparation of magnetic nanoparticles and coating with glycine to remove heavy metals such as Cu+2. The magnetic nanoparticles were prepared by co-precipitation method using using ferrous sulphate and potassium nitrate in presence of potassium hydroxide. Different instrumental analysis such as XRD, TEM, SEM and EDAX were used to study the magnetic nanoparticles which produced and comparing it after coated with glycine. The optimum conditions which reflect the high efficiency of removal are pH 10, concentration of the heavy metal 200 ppm, dosage 0.05 g and for 24 h duration time. Therefore we recommend using magnetic nanoparticles coated with glycine for removal of heavy metals.

  12. Superhydrophobic powder additives to enhance chemical agent resistant coating systems for military equipment for the U.S. Marine Corps (USMC) Corrosion Prevention and Control (CPAC) Program

    Energy Technology Data Exchange (ETDEWEB)

    Pawel, Steven J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Armstrong, Beth L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Haynes, James A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-07-01

    The primary goal of the CPAC program at ORNL was to explore the feasibility of introducing various silica-based superhydrophobic (SH) powder additives as a way to improve the corrosion resistance of US Department of Defense (DOD) military-grade chemical agent resistant coating (CARC) systems. ORNL had previously developed and patented several SH technologies of interest to the USMC, and one of the objectives of this program was to identify methods to incorporate these technologies into the USMC’s corrosion-resistance strategy. This report discusses findings of the CPAC and their application.

  13. Chemical approach to the deposition of textured CeO2 buffer layers based on sol gel dip coating

    International Nuclear Information System (INIS)

    The widespread use of vacuum techniques for the development of coated conductors, in which buffer and superconducting (REBa2Cu3O7-δ) layers are deposited epitaxially on a substrate, is well established in the research environment. However, obtaining uninterrupted deposition at high speed, increasing flexibility in composition and in film thickness and attaining independence of geometric constraints are areas in which many vacuum techniques will need sustained development in order to answer industrial demands. This work describes the deposition of textured CeO2 buffer layers based on sol gel dip coating under atmospheric environment and from aqueous precursor materials. Research has been performed towards the deposition of CeO2-buffer layers using the amorphous citrate method on sapphire substrates and Ni-W foils. Coating is performed using the dip-coating technique, which allows extension to a continuous system. The withdrawal speed and the thermal treatment have been optimised in order to obtain highly oriented (001) layers exhibiting a smooth and crack-free morphology both on ceramic and metallic substrates. From the results it was concluded that sintering atmosphere and sintering temperature play a crucial role in the growth mechanism. This study describes the structural and morphological analysis of the thin layer with special attention to the difference between ceramic and metallic substrates. (orig.)

  14. Synthesis of BaTiO3 nanoparticles from TiO2-coated BaCO3 particles derived using a wet-chemical method

    Directory of Open Access Journals (Sweden)

    Yuuki Mochizuki

    2014-03-01

    Full Text Available BaCO3 particles coated with amorphous TiO2 precursor are prepared by a wet chemical method to produce BaTiO3 nanoparticles at low temperatures. Subsequently, we investigate the formation behavior of BaTiO3 particles and the particle growth behavior when the precursor is subjected to heat treatment. The state of the amorphous TiO2 coating on the surface of BaCO3 particles depends on the concentration of NH4HCO3, and the optimum concentration is found to be in the range 0.5–1.0 M. Thermogravimetric curves of the BaCO3 particles coated with the TiO2 precursor, prepared from BaCO3 particles of various sizes, show BaTiO3 formation occurring mainly at 550–650 °C in the case of fine BaCO3 particles. However, as evidenced from the curves, the temperature of formation of BaTiO3 shifts to higher values with an increase in the size of the BaCO3 particles. The average particle size of single phase BaTiO3 at heat-treatment temperature of 650–900 °C is observed to be in the range 60–250 nm.

  15. Advanced zirconia-coated carbonyl-iron particles for acidic magnetorheological finishing of chemical-vapor-deposited ZnS and other IR materials

    Science.gov (United States)

    Salzman, S.; Giannechini, L. J.; Romanofsky, H. J.; Golini, N.; Taylor, B.; Jacobs, S. D.; Lambropoulos, J. C.

    2015-10-01

    We present a modified version of zirconia-coated carbonyl-iron (CI) particles that were invented at the University of Rochester in 2008. The amount of zirconia on the coating is increased to further protect the iron particles from corrosion when introduced to an acidic environment. Five low-pH, magnetorheological (MR) fluids were made with five acids: acetic, hydrochloric, nitric, phosphoric, and hydrofluoric. All fluids were based on the modified zirconia-coated CI particles. Off-line viscosity and pH stability were measured for all acidic MR fluids to determine the ideal fluid composition for acidic MR finishing of chemical-vapor-deposited (CVD) zinc sulfide (ZnS) and other infrared (IR) optical materials, such as hot-isostatic-pressed (HIP) ZnS, CVD zinc selenide (ZnSe), and magnesium fluoride (MgF2). Results show significant reduction in surface artifacts (millimeter-size, pebble-like structures on the finished surface) for several standard-grade CVD ZnS substrates and good surface roughness for the non-CVD MgF2 substrate when MR finished with our advanced acidic MR fluid.

  16. Metallic coating of microspheres

    International Nuclear Information System (INIS)

    Extremely smooth, uniform metal coatings of micrometer thicknesses on microscopic glass spheres (microspheres) are often needed as targets for inertial confinement fusion (ICF) experiments. The first part of this paper reviews those methods used successfully to provide metal coated microspheres for ICF targets, including magnetron sputtering, electro- and electroless plating, and chemical vapor pyrolysis. The second part of this paper discusses some of the critical aspects of magnetron sputter coating of microspheres, including substrate requirements, the sticking of microspheres during coating (preventing a uniform coating), and the difficulties in growing the desired dense, smooth, uniform microstructure on continuously moving spherical substrates

  17. 水基化铣可剥涂料碱化铣应用工艺研究%Application Process of Alkaline Milling of Water -based Chemical Milling Peelable Coating

    Institute of Scientific and Technical Information of China (English)

    王帅; 杨魁; 于钦泰; 胡友雄

    2016-01-01

    The milling peelable coating chemical milling processing of coated film,coating film cu-ring,carved and alkali corrosion processing and application technology by using water as dispersing medium are studied.Application process path,technological parameters and chemical milling solution ratio which are suitable for water -based milling peelable coating were determined.%对以水为分散介质的化铣可剥涂料在化学铣切加工中的涂覆成膜、涂膜硫化、刻型及碱腐蚀加工应用工艺进行了研究,实验确定了适于水基化铣可剥涂料的应用工艺路径、工艺参数及化铣液配比。

  18. Photocatalytic TiO2 and Doped TiO2 Coatings to Improve the Hygiene of Surfaces Used in Food and Beverage Processing—A Study of the Physical and Chemical Resistance of the Coatings

    Directory of Open Access Journals (Sweden)

    Parnia Navabpour

    2014-07-01

    Full Text Available TiO2 coatings deposited using reactive magnetron sputtering and spray coating methods, as well as Ag- and Mo-doped TiO2 coatings were investigated as self-cleaning surfaces for beverage processing. The mechanical resistance and retention of the photocatalytic properties of the coatings were investigated over a three-month period in three separate breweries. TiO2 coatings deposited using reactive magnetron sputtering showed better mechanical durability than the spray coated surfaces, whilst the spray-deposited coating showed enhanced retention of photocatalytic properties. The presence of Ag and Mo dopants improved the photocatalytic properties of TiO2 as well as the retention of these properties. The spray-coated TiO2 was the only coating which showed light-induced hydrophilicity, which was retained in the coatings surviving the process conditions.

  19. Chemical treatment and biomimetic coating evaluating in zirconia-alumina ceramics; Avaliacao de tratamentos quimicos e recobrimento biomimetico em ceramicas de alumina-zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Amanda Abati

    2007-07-01

    Ceramic materials, as alumina and zirconia have been explored along the years as biomaterials application. The bio inert nature has been stimulating the development of new alternatives, as chemical treatments to improve the biological application of these ceramics. The biomimetic process of bio inert ceramics for coating apatite is based on soaking the implant in a simulated body fluid, SBF, with ion concentrations nearly equal to those of human blood plasma. The bioactivity of the material is related with the formation of a layer constituted of hydroxyapatite low crystalline, similar to the biological apatite. The biocompatibility associated to the structural properties of the alumina and zirconia has been stimulating the clinical use of these materials, mainly in areas of larger mechanical requests, places not recommended for bioactive hydroxyapatite, for instance. In this work samples of alumina, zirconia doped with Yttria (3% mol) and composites of alumina and zirconia doped with Yttria (3% mol) were prepared by co-precipitation method, calcinate, sintered, chemically treated with solutions of acid phosphoric and sodium hydroxide and them immersed in 1.0 M and 1.5 M SBF. The calcinate powders were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), gas adsorption (BET) and laser diffraction. The XRD results indicate that the samples are low crystalline. It was observed for BET that the samples present high specific surface area. The results of laser diffraction and SEM showed that the powders are agglomerates. The sintered samples were analyzed by XRD, SEM and X-ray fluorescence (XRF). The phases quantified by Rietveld method were: cubic, tetragonal and monoclinic of the zirconia, besides the phase alpha of the alumina. The chemical treatment with phosphoric acid didn't present a tendency of larger apatite formation in relation to the samples no chemically treated. The treatment with sodium hydroxide provoked accentuated transformation

  20. Coated particle waste form development

    International Nuclear Information System (INIS)

    Coated particle waste forms have been developed as part of the multibarrier concept at Pacific Northwest Laboratory under the Alternative Waste Forms Program for the Department of Energy. Primary efforts were to coat simulated nuclear waste glass marbles and ceramic pellets with low-temperature pyrolytic carbon (LT-PyC) coatings via the process of chemical vapor deposition (CVD). Fluidized bed (FB) coaters, screw agitated coaters (SAC), and rotating tube coaters were used. Coating temperatures were reduced by using catalysts and plasma activation. In general, the LT-PyC coatings did not provide the expected high leach resistance as previously measured for carbon alone. The coatings were friable and often spalled off the substrate. A totally different concept, thermal spray coating, was investigated at PNL as an alternative to CVD coating. Flame spray, wire gun, and plasma gun systems were evaluated using glass, ceramic, and metallic coating materials. Metal plasma spray coatings (Al, Sn, Zn, Pb) provided a two to three orders-of-magnitude increase in chemical durability. Because the aluminum coatings were porous, the superior leach resistance must be due to either a chemical interaction or to a pH buffer effect. Because they are complex, coated waste form processes rank low in process feasibility. Of all the possible coated particle processes, plasma sprayed marbles have the best rating. Carbon coating of pellets by CVD ranked ninth when compared with ten other processes. The plasma-spray-coated marble process ranked sixth out of eleven processes

  1. Fiscal 1997 report on the results on the international standardization R and D. Development of chemical methods to analyze/evaluate metallic coatings of surface treated steel coating sheets; 1997 nendo seika hokokusho kokusai hyojun soseigata kenkyu kaihatsu. Hyomen shori koban mekkiso no kagaku bunseki hyoka hoho no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The paper studied the international standardization of the chemical analysis method and glow discharge optical emission spectrometry. Chemical composition and coating thickness (g/m{sup 2}) of 14 kinds of specimens including alloy coatings and organic coating with zinc and aluminum as base were analyzed by the above-mentioned methods to examine the relation between the both. As the chemical analysis method, used was inductively coupled plasma atomic emission spectrometry. To study the relation between the methods, it was found to be necessary to recognize morphology at the boundary between the coating and base steel using, for example, scanning electron microscope (SEM) and electro-probe micro-analysis (EPMA). To measure traceability of the analysis method, with the chemical analysis method as a judgement method, it is necessary to make reference materials by coating materials, to use the calibration graph confirmed by the materials and to adopt the glow discharge optical emission spectrometry. On the basis of such way of thinking, drafts were worked out for the international standardization of the chemical analysis method and glow discharge optical emission spectrometry. 7 refs., 117 figs., 33 tabs.

  2. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  3. Electrochemical Properties of Chemically Processed SiOx as Coating Material in Lithium-Ion Batteries with Si Anode

    Directory of Open Access Journals (Sweden)

    Hee-June Jeong

    2014-01-01

    Full Text Available A SiOx coating material for Si anode in lithium-ion battery was processed by using SiCl4 and ethylene glycol. The produced SiOx particles after heat treatment at 725°C for 1 h were porous and irregularly shaped with amorphous structure. Pitch carbon added to SiOx was found to strongly affect solid electrolyte interphase stabilization and cyclic stability. When mixed with an optimal amount of 30 wt% pitch carbon, the SiOx showed a high charge/discharge cyclic stability of about 97% for the 2nd to the 50th cycle. The initial specific capacity of the SiOx was measured to be 1401 mAh/g. On the basis of the evaluation of the SiOx coating material, the process utilized in this study is considered an efficient method to produce SiOx with high performance in an economical way.

  4. Physical and chemical characterization of Ag-doped Ti coatings produced by magnetron sputtering of modular targets

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, Tobias [Department for Functional Materials in Medicine and Dentistry, School of Dentistry, University of Würzburg, Pleicherwall 2, 97070 Würzburg (Germany); Institute of Tissue Engineering and Regenerative Medicine, University Hospital of the Julius-Maximilians University, Röntgenring 11, 97070 Würzburg (Germany); Warmuth, Franziska [Department for Functional Materials in Medicine and Dentistry, School of Dentistry, University of Würzburg, Pleicherwall 2, 97070 Würzburg (Germany); Werner, Ewald; Hertl, Cornelia [Institute of Materials Science and Mechanics of Materials, Technical University of Munich, Boltzmannstrasse 15, 85748 Garching (Germany); Groll, Jürgen; Gbureck, Uwe [Department for Functional Materials in Medicine and Dentistry, School of Dentistry, University of Würzburg, Pleicherwall 2, 97070 Würzburg (Germany); Moseke, Claus, E-mail: claus.moseke@fmz.uni-wuerzburg.de [Department for Functional Materials in Medicine and Dentistry, School of Dentistry, University of Würzburg, Pleicherwall 2, 97070 Würzburg (Germany)

    2014-11-01

    Silver-doped Ti films were produced using a single magnetron sputtering source equipped with a titanium target containing implemented silver modules under variation of bias voltage and substrate temperature. The Ti(Ag) films were characterized regarding their morphology, contact angle, phase composition, silver content and distribution as well as the elution of Ag{sup +} ions into cell media. SEM and AFM pictures showed that substrate heating during film deposition supported the formation of even and dense surface layers with small roughness values, an effect that could even be enforced, when a substrate bias voltage was applied instead. The deposition of both Ti and Ag was confirmed by X-ray diffraction. ICP-MS and EDX showed a clear correlation between the applied sputtering parameters and the silver content of the coatings. Surface-sensitive XPS measurements revealed that higher substrate temperatures led to an accumulation of Ag in the near-surface region, while the application of a bias voltage had the opposite effect. Additional elution measurements using ICP-MS showed that the release kinetics depended on the amount of silver located at the film surface and hence could be tailored by variation of the sputter parameters. - Highlights: • Modular targets were used to deposit Ti(Ag) films. • Ag-content is adjustable by bias voltage, sputtering power and substrate temperature. • Coating parameters significantly change film morphology and roughness. • A critical parameter for Ag release is the fraction of silver on the film surface.

  5. Physical and chemical characterization of Ag-doped Ti coatings produced by magnetron sputtering of modular targets

    International Nuclear Information System (INIS)

    Silver-doped Ti films were produced using a single magnetron sputtering source equipped with a titanium target containing implemented silver modules under variation of bias voltage and substrate temperature. The Ti(Ag) films were characterized regarding their morphology, contact angle, phase composition, silver content and distribution as well as the elution of Ag+ ions into cell media. SEM and AFM pictures showed that substrate heating during film deposition supported the formation of even and dense surface layers with small roughness values, an effect that could even be enforced, when a substrate bias voltage was applied instead. The deposition of both Ti and Ag was confirmed by X-ray diffraction. ICP-MS and EDX showed a clear correlation between the applied sputtering parameters and the silver content of the coatings. Surface-sensitive XPS measurements revealed that higher substrate temperatures led to an accumulation of Ag in the near-surface region, while the application of a bias voltage had the opposite effect. Additional elution measurements using ICP-MS showed that the release kinetics depended on the amount of silver located at the film surface and hence could be tailored by variation of the sputter parameters. - Highlights: • Modular targets were used to deposit Ti(Ag) films. • Ag-content is adjustable by bias voltage, sputtering power and substrate temperature. • Coating parameters significantly change film morphology and roughness. • A critical parameter for Ag release is the fraction of silver on the film surface

  6. TABLET COATING TECHNIQUES: CONCEPTS AND RECENT TRENDS

    Directory of Open Access Journals (Sweden)

    Gupta Ankit

    2012-09-01

    Full Text Available Tablet coating is a common pharmaceutical technique of applying a thin polymer-based film to a tablet or a granule containing active pharmaceutical ingredients (APIs. Solid dosage forms are coated for a number of reasons, the most important of which is controlling the release profiles. The amount of coating on the surface of a tablet is critical to the effectiveness of the oral dosage form. Tablets are usually coated in horizontal rotating pans with the coating solution sprayed onto the free surface of the tablet bed. The advantages of tablet coating are taste masking, odour masking, physical and chemical protection, protects the drug from the gastric environment etc. There are various techniques for tablet coating such as sugar coating, film coating, and enteric coating. Recent trends in pharmaceutical technologies are the development of coating methods which overcomes the various disadvantages associated with solvent based coatings. In these latest technologies coating materials are directly coated onto the surface of solid dosage forms without using any solvent. Various solventless coatings are available such as electrostatic dry coating, magnetically assisted impaction coating, compression coating, hot melt coating, powder coating, and supercritical fluid coating. Supercell Coating Technology is a revolutionary tablet coating that accurately deposits controlled amounts of coating materials on tablets even if they are extremely hygroscopic or friable. Magnetically assisted impaction coating, electrostatic dry coating in solventless coatings, aqueous film coating and Supercell coating technology are also available recent technique of coating. An ideal tablet should be free from any visual defect or functional defect. The advancements and innovations in tablet manufacture have not decreased the problems, often encountered in the production, instead have increased the problems, mainly because of the complexities of tablet presses; and/or the

  7. Plasma assisted metal-organic chemical vapor deposition of hard chromium nitride thin film coatings using chromium(III) acetylacetonate as the precursor

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, Arup; Kuppusami, P.; Lawrence, Falix; Raghunathan, V.S.; Antony Premkumar, P.; Nagaraja, K.S

    2004-06-15

    A new technique has been developed for depositing hard nanocrystalline chromium nitride (CrN) thin films on metallic and ceramic substrates using plasma assisted metal-organic chemical vapor deposition (PAMOCVD) technique. In this low temperature and environment-friendly process, a volatile mixture of chromium(III) acetylacetonate and either ammonium iodide or ammonium bifluoride were used as precursors. Nitrogen and hydrogen have been used as the gas precursors. By optimizing the processing conditions, a maximum deposition rate of {approx}0.9 {mu}m/h was obtained. A comprehensive characterization of the CrN films was carried out using X-ray diffraction (XRD), microhardness, and microscopy. The microstructure of the CrN films deposited on well-polished stainless steel (SS) showed globular particles, while a relatively smooth surface morphology was observed for coatings deposited on polished yittria-stabilized zirconia (YSZ)

  8. SEMICONDUCTOR DEVICES Density-controllable nonvolatile memory devices having metal nanocrystals through chemical synthesis and assembled by spin-coating technique

    Science.gov (United States)

    Guangli, Wang; Yubin, Chen; Yi, Shi; Lin, Pu; Lijia, Pan; Rong, Zhang; Youdou, Zheng

    2010-12-01

    A novel two-step method is employed, for the first time, to fabricate nonvolatile memory devices that have metal nanocrystals. First, size-averaged Au nanocrystals are synthesized chemically; second, they are assembled into memory devices by a spin-coating technique at room temperature. This attractive approach makes it possible to tailor the diameter and control the density of nanocrystals individually. In addition, processes at room temperature prevent Au diffusion, which is a main concern for the application of metal nanocrystal-based memory. The experimental results, both the morphology characterization and the electrical measurements, reveal that there is an optimum density of nanocrystal monolayer to balance between long data retention and a large hysteresis memory window. At the same time, density-controllable devices could also feed the preferential emphasis on either memory window or retention time. All these facts confirm the advantages and novelty of our two-step method.

  9. The physics of plasma-enhanced chemical vapour deposition for large-area coating: industrial application to flat panel displays and solar cells

    International Nuclear Information System (INIS)

    Designing plasma-enhanced chemical vapour deposition (PECVD) reactors to coat large-area glass plates (∼1 m2) for flat panel display or solar cell manufacturing raises challenging issues in physics and chemistry as well as mechanical, thermal, and electrical engineering, and material science. In such reactive glow discharge plasma slabs, excited at RF frequency (from 13.56 MHz up to ∼100 MHz), the thin-film deposition uniformity is determined by the gas flow distribution, as well as the RF voltage distribution along the electrodes, and by local plasma perturbations at the reactor boundaries. All these aspects can be approached by analytical and numerical modelling. Moreover, the film properties are largely determined by the plasma chemistry involving the neutral radicals contributing to film growth, the effect of ion bombardment, and the formation and trapping of dust triggered by homogeneous nucleation. This paper will review progress in this field, with particular emphasis on modelling developments. (author)

  10. 马蔺子种皮乙醚提取物化学成分分析%Chemical Constituents of Ethyl Ether Spirit of Seed Coat of Iris

    Institute of Scientific and Technical Information of China (English)

    李明; 魏宁漪; 牛剑钊

    2011-01-01

    目的:研究马蔺种子皮乙醚提取物的化学成分.方法:采用GC-MS法分析与鉴定化学成分.结果:经气质联用色谱分离、质谱NIST标准图库检索,并参照有关文献,确认了25个化合物,含量较高的物质有马蔺子甲素、马蔺子甲素反式异构体和马蔺子乙素等.化合物的类型主要为饱和脂肪酸、不饱和脂肪酸、芳香醋等.结论:利用GC-MS分析鉴定马蔺子种皮脂溶性成分,具有快速、稳定、重现性好的特点,可用于马蔺药材成分的分析鉴定.%Objective: To investigate the chemical constituents of ethyl ether spirit of seed coat of Iris.Method:To analyze and identify the chemical constituents by GC-MS. Result:We separated the extraction by GC-MS method, and affirmed 26 peaks by NIST workstation and reference documentation. The contents of irisquinone,(E) irisquinone isomer and pallasone B were high and main types of the constituents were saturated fatty acid ester,unsaturated fatty acid ester, fragrance ester, organic acid, and alkaloid etc. Conclusion: Analyzing and identify composition by GC-MS is fast, stable, and has fine reproduction, it can be used for composition analysis of seed coat of iris.

  11. Physico-chemical, respiratory and fungicide residue changes in wax coated mandarin fruit stored at chilling temperature with intermittent warming.

    Science.gov (United States)

    Ladaniya, Milind Shivratan

    2011-04-01

    Influence of chilling temperature, intermittent warming (IW) and fungicidal wax coating was evaluated during storage of 'Nagpur' mandarins (Citrus reticulata Blanco). Fruits were light green coloured with slight colour-break at the start of storage. Waxed and non-waxed fruits were stored at 3.5 °C (constant), 2 weeks at 3.5 °C followed by IW for 1 week at 19.5 °C (cycle) and at 6.5 °C (constant), and were evaluated immediately after 30, 45, 60, 75 days and also after 1 week holding at ambient condition (24 ± 2 °C, 60-70% RH). There was no chilling injury to fruit under IW treatment irrespective of coating. At 3.5 °C (constant) chilling injury appeared after 45 days during 1 week holding and thereafter increased at each storage interval. Wax coated fruit had lower chilling injury. Fruit under IW treatment and at 6.5 °C (constant) developed yellow-orange colour while at 3.5 °C (constant) fruit remained green during storage. Juice content, titratable acidity and ascorbic acid contents were not affected by temperature regimes and waxing while total soluble solids content was higher with IW treatment. Reducing and total sugars were higher in fruits stored at IW treatment and at 6.5 °C (constant) than at 3.5 °C (constant). Total peel phenols content were not significantly affected by waxing and temperature regimes. However, loss of phenols content was higher at 3.5 °C (constant). Phenol content decreased during storage. At 3.5 °C (constant), chlorophyll ('a', 'b' and total) content in peel was maximum while total carotenoids were minimum with little colour development. Rapid colour development was recorded under IW and also at 1 week holding. Wax coating delayed colour development at 3.5 °C (constant). Initially carbendazim residues were higher in peel (4.0 ppm) and pulp (3.2 ppm) of waxed fruit than in non-waxed (3.2 ppm in peel and 3.1 ppm in pulp) fruit. Overall drop in residues till storage up to 75 days+ 1 week over the

  12. Corrosion resistant coatings (Al2O3) produced by metal organic chemical vapour deposition using aluminium-tri-sec-butoxide

    NARCIS (Netherlands)

    Haanappel, V.A.C.; Corbach, van H.D.; Fransen, T.; Gellings, P.J.

    1993-01-01

    The metal organic chemical vapour deposition (MOCVD) of amorphous alumina films on steel was performed in nitrogen at atmospheric pressure. This MOCVD process is based on the thermal decomposition of aluminium-tri-sec-butoxide (ATSB). The effect of the deposition temperature (within the range 290–42

  13. Growth of carbon nanofiber coatings on nickel thin films on fused silica by catalytic thermal chemical vapor deposition: On the use of titanium, titanium–tungsten and tantalum as adhesion layers

    NARCIS (Netherlands)

    Thakur, D.B.; Tiggelaar, R.M.; Gardeniers, J.G.E.; Lefferts, L.; Seshan, K.

    2009-01-01

    Coatings of carbon nanofiber (CNF) layers were synthesized on fused silica substrates using a catalytic thermal chemical vapor deposition process (C-TCVD). The effects of various adhesion layers–titanium, titanium–tungsten and tantalum–under the nickel thin film on the attachment of carbon nanofiber

  14. Final Technical Report: A Paradigm Shift in Chemical Processing: New Sustainable Chemistries for Low-VOC Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Kenneth F.

    2006-07-26

    The project employed new processes to make emulsion polymers from reduced levels of petroleum-derived chemical feedstocks. Most waterborne paints contain spherical, emulsion polymer particles that serve as the film-forming binder phase. Our goal was to make emulsion polymer particles containing 30 percent feedstock that would function as effectively as commercial emulsions made from higher level feedstock. The processes developed yielded particles maintained their film formation capability and binding capacity while preserving the structural integrity of the particles after film formation. Rohm and Haas Company (ROH) and Archer Daniels Midland Company (ADM) worked together to employ novel polymer binders (ROH) and new, non-volatile, biomass-derived coalescing agents (ADM). The University of Minnesota Department of Chemical Engineering and Material Science utilized its unique microscopy capabilities to characterize films made from the New Emulsion Polymers (NEP).

  15. Effect of silica coating on bond strength between a gold alloy and metal bracket bonded with chemically cured resin

    OpenAIRE

    Ryu, Min-Ju; Gang, Sung-Nam; Lim, Sung-Hoon

    2014-01-01

    Objective The purpose of this study was to evaluate the effects of three different surface conditioning methods on the shear bond strength (SBS) of metal brackets bonded directly to gold alloy with chemically cured resin. Methods Two hundred ten type III gold alloy specimens were randomly divided into six groups according to the combination of three different surface conditioning methods (aluminum oxide sandblasting only, application of a metal primer after aluminum oxide sandblasting, silica...

  16. INTERACTION-MEDIATED GROWTH OF CARBON NANOTUBES ON ACICULAR SILICA-COATED α-Fe CATALYST BY CHEMICAL VAPOR DEPOSITION

    Institute of Scientific and Technical Information of China (English)

    Qixiang Wang; Guoqing Ning; Fei Wei; Guohua Luo

    2003-01-01

    Multi-walled carbon nanotubes (MWNTs) with 20 nm outer diameter were prepared by chemical vapor deposition of ethylene using ultrafine surface-modified acicular α-Fe catalyst particles. The growth mechanism of MWNTs on the larger catalyst particles are attributed to the interaction between the Fe nanoparticles with the surface-modified silica layer. This interaction-mediated growth mechanism is illustrated by studying the electronic, atomic and crystal properties of surface-modified catalysts and MWNTs products by characterization with X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), thermal gravimetric analysis (TGA) and Raman spectra.

  17. Effect of Chemical Vapor Deposition Temperature on Properties of Tantalum Coatings%CVD温度对钽沉积层性能的影响

    Institute of Scientific and Technical Information of China (English)

    蔡宏中; 魏巧灵; 魏燕; 陈力; 郑旭; 胡昌义

    2012-01-01

    介绍了化学气相沉积(CVD)制备难熔金属钽涂层的原理及方法.采用冷壁式化学气相沉积法,在钼基体上沉积出难熔金属钽层.分析研究了CVD温度对沉积层的沉积速率、组织、结构和硬度等的影响.结果表明:在1000~1200℃温度范围,沉积速率随温度升高而增大 ;当温度超过1200℃时,沉积速率随温度的升高反而略有减小 ;沉积层组织呈柱状晶并随温度的升高逐渐增大 ;沉积层的硬度及密度随温度的升高而逐渐降低.化学气相沉积钽的最佳温度在1100℃左右.%The principle and method of chemical vapor deposition tantalum were proposed. Through the cold wall deposition, tantalum coatings were deposited on molybdenum substrates. The effect of CVD temperature on deposition rate, microstructure and hardness of Ta coatings was investigated. The results show that with the increasing of the deposition temperature, the deposition rate increases in the range of 1000-1200 ℃; above 1200 ℃, the deposition rate decreases; the microstructure of the deposition layer is of columnar grain and the grain size increases with the increasing of the deposition temperature. Meanwhile the hardness and density of the deposition layer decreases. The optimal deposition temperature of CVD tantalum layer is about 1100 ℃.

  18. Photocatalytic Functional Coating of TiO2 Thin Film Deposited by Cyclic Plasma Chemical Vapor Deposition at Atmospheric Pressure

    Science.gov (United States)

    Kwon, Jung-Dae; Rha, Jong-Joo; Nam, Kee-Seok; Park, Jin-Seong

    2011-08-01

    Photocatalytic TiO2 thin films were prepared with titanium tetraisopropoxide (TTIP) using cyclic plasma chemical vapor deposition (CPCVD) at atmospheric pressure. The CPCVD TiO2 films contain carbon-free impurities up to 100 °C and polycrystalline anatase phases up to 200 °C, due to the radicals and ion-bombardments. The CPCVD TiO2 films have high transparency in the visible wavelength region and absorb wavelengths below 400 nm (>3.2 eV). The photocatalytic effects of the CPCVD TiO2 and commercial sprayed TiO2 films were measured by decomposing methylene blue (MB) solution under UV irradiation. The smooth CPCVD TiO2 films showed a relatively lower photocatalytic efficiency, but superior catalyst-recycling efficiency, due to their high adhesion strength on the substrates. This CPCVD technique may provide the means to produce photocatalytic thin films with low cost and high efficiency, which would be a reasonable candidate for practical photocatalytic applications, because of the reliability and stability of their photocatalytic efficiency in a practical environment.

  19. Modified DLC coatings prepared in a large-scale reactor by dual microwave/pulsed-DC plasma-activated chemical vapour deposition

    International Nuclear Information System (INIS)

    Diamond-Like Carbon (DLC) films find abundant applications as hard and protective coatings due to their excellent mechanical and tribological performances. The addition of new elements to the amorphous DLC matrix tunes the properties of this material, leading to an extension of its scope of applications. In order to scale up their production to a large plasma reactor, DLC films modified by silicon and oxygen additions have been grown in an industrial plant of 1m3 by means of pulsed-DC plasma-activated chemical vapour deposition (PACVD). The use of an additional microwave (MW) source has intensified the glow discharge, partly by electron cyclotron resonance (ECR), accelerating therefore the deposition process. Hence, acetylene, tetramethylsilane (TMS) and hexamethyldisiloxane (HMDSO) constituted the respective gas precursors for the deposition of a-C:H (DLC), a-C:H:Si and a-C:H:Si:O films by dual MW/pulsed-DC PACVD. This work presents systematic studies of the deposition rate, hardness, adhesion, abrasive wear and water contact angle aimed to optimize the technological parameters of deposition: gas pressure, relative gas flow of the monomers and input power. This study has been completed with measures of the atomic composition of the samples. Deposition rates around 1 μm/h, typical for standard processes held in the large reactor, were increased about by a factor 10 when the ionization source has been operated in ECR mode

  20. Growth of thick La2Zr2O7 buffer layers for coated conductors by polymer-assisted chemical solution deposition

    International Nuclear Information System (INIS)

    Highlights: • We develops a low-cost and high-efficient technology of fabricating LZO buffer layers. • Sufficient thickness LZO buffer layers have been obtained on NiW (2 0 0) alloy substrate. • Highly biaxially textured YBCO thin film has been deposited on LZO/NiW. - Abstract: La2Zr2O7 (LZO) epitaxial films have been deposited on LaAlO3 (LAO) (1 0 0) single-crystal surface and bi-axially textured NiW (2 0 0) alloy substrate by polymer-assisted chemical solution deposition, and afterwards studied with XRD, SEM and AFM approaches. Highly in-plane and out-of-plane oriented, dense, smooth, crack free and with a sufficient thickness (>240 nm) LZO buffer layers have been obtained on LAO (1 0 0) single-crystal surface; The films deposited on NiW (2 0 0) alloy substrate are also found with high degree in-plane and out-of-plane texturing, good density with pin-hole-free, micro-crack-free nature and a thickness of 300 nm. Highly epitaxial 500 nm thick YBa2Cu3O7−x (YBCO) thin film exhibits the self-field critical current density (Jc) reached 1.3 MA/cm2 at 77 K .These results demonstrate the LZO epi-films obtained with current techniques have potential to be a buffer layer for REBCO coated conductors

  1. Growth of thick La2Zr2O7 buffer layers for coated conductors by polymer-assisted chemical solution deposition

    Science.gov (United States)

    Zhang, Xin; Zhao, Yong; Xia, Yudong; Guo, Chunsheng; Cheng, C. H.; Zhang, Yong; Zhang, Han

    2015-06-01

    La2Zr2O7 (LZO) epitaxial films have been deposited on LaAlO3 (LAO) (1 0 0) single-crystal surface and bi-axially textured NiW (2 0 0) alloy substrate by polymer-assisted chemical solution deposition, and afterwards studied with XRD, SEM and AFM approaches. Highly in-plane and out-of-plane oriented, dense, smooth, crack free and with a sufficient thickness (>240 nm) LZO buffer layers have been obtained on LAO (1 0 0) single-crystal surface; The films deposited on NiW (2 0 0) alloy substrate are also found with high degree in-plane and out-of-plane texturing, good density with pin-hole-free, micro-crack-free nature and a thickness of 300 nm. Highly epitaxial 500 nm thick YBa2Cu3O7-x (YBCO) thin film exhibits the self-field critical current density (Jc) reached 1.3 MA/cm2 at 77 K .These results demonstrate the LZO epi-films obtained with current techniques have potential to be a buffer layer for REBCO coated conductors.

  2. Phase Evolution of YBa2Cu3O7-x films by all-chemical solution deposition route for coated conductors

    DEFF Research Database (Denmark)

    Yue, Zhao; Tang, Xiao; Wu, Wei;

    2014-01-01

    In order to understand the all-chemical-solution-deposition (CSD) processes for manufacturing coated conductors, we investigated the phase evolution of YBa2Cu3O7 (YBCO) films deposited by a low-fluorine metal-organic solution deposition (LF-MOD) method on CSD derived Ce0.9La0.1O2/Gd2Zr2O7/Ni......W. It is shown that the phase transition from the pyrolyzed film to fully converted YBCO film in the LF-MOD process is similar to that in typical trifluoroacetates-metal organic deposition (TFA-MOD) processes even though the amount of TFA in the solution is reduced by almost one half compared with typical TFA...... deposited at high sintering temperatures. Based on these results, the optimized growth conditions of YBCO films were established, and a high critical current density (Jc) of about 2 MA/cm2 (77 K, self field) is achieved in a 200 nm thick YBCO film in the architecture made by our all CSD route....

  3. Sm-doped CeO{sub 2} single buffer layer for YBCO coated conductors by polymer assisted chemical solution deposition (PACSD) method

    Energy Technology Data Exchange (ETDEWEB)

    Li, G.; Pu, M.H.; Sun, R.P.; Wang, W.T.; Wu, W.; Zhang, X.; Yang, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); Cheng, C.H. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Zhao, Y. [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia)], E-mail: yzhao@home.swjtu.edu.cn

    2008-10-20

    An over 150 nm thick Sm{sub 0.2}Ce{sub 0.8}O{sub 1.9-x} (SCO) single buffer layer has been deposited on bi-axially textured NiW (2 0 0) alloy substrate. Highly in-plane and out-of-plane oriented, dense, smooth and crack free SCO single layer has been obtained via a polymer-assisted chemical solution deposition (PACSD) approach. YBCO thin film has been deposited equally via a PACSD route on the SCO-buffered NiW, the as grown YBCO yielding a sharp transition at T{sub c0} = 87 K as well as J{sub c}(0 T, 77 K) {approx} 1 MA/cm{sup 2}. These results indicates that RE (lanthanides other than Ce) doping may be an effective approach to improve the critical thickness of solution derived CeO{sub 2} film, which renders it a promising candidate as single buffer layer for YBCO coated conductors.

  4. Effect of carboxymethyl cellulose edible coating containing Zataria multiflora essential oil and grape seed extract on chemical attributes of rainbow trout meat

    Directory of Open Access Journals (Sweden)

    Mojtaba Raeisi

    2014-06-01

    Full Text Available Meat products, especially fish meat, are very susceptible to lipid oxidation and microbial spoilage. In this study, first, gas chromatography mass spectrometry (GC-MS analysis of Zataria multiflora essential oil (ZEO components was done and then two concentrations of ZEO, (1% and 2% and two concentrations of grape seed extract (GSE, (0.5% and 1% were used in carboxymethyl cellulose coating alone and in combination, and their antioxidant effects on rainbow trout meat were evaluated in a 20-day period using thiobarbituric acid reactive substances (TBARS test. Their effects on total volatile basic nitrogen (TVBN and pH were evaluated as well. The main components of ZEO are thymol and carvacrol. These components significantly decreased production of thio-barbituric acid (TBA, TVBN and pH level of fish meat. The initial pH, TVBN and TBA content was 6.62, 12.67 mg N per 100 g and 0.19 mg kg-1, respectively. In most treatments significant (p < 0.05 effects on aforementioned factors was seen during storage at 4 ˚C. The results indicated that use of ZEO and GSE as a natural antioxidant agents was effective in reducing undesirable chemical reactions in storage of fish meat.

  5. Graphene Coatings

    DEFF Research Database (Denmark)

    Stoot, Adam Carsten; Camilli, Luca; Bøggild, Peter

    2014-01-01

    Owing to its remarkable electrical and mechanical properties, graphene has been attracting tremendous interest in materials science. In particular, its chemical stability and impermeability make it a promising protective membrane. However, recent investigations reveal that single layer graphene...... cannot be used as a barrier in the long run, due to galvanic corrosion phenomena arising when oxygen or water penetrate through graphene cracks or domain boundaries. Here, we overcome this issue by using a multilayered (ML) graphene coating. Our lab- as well as industrial-scale tests demonstrate that ML...... graphene can effectively protect Ni in harsh environments, even after long term exposure. This is made possible by the presence of a high number of graphene layers, which can efficiently mask the cracks and domain boundaries defects found in individual layers of graphene. Our findings thus show...

  6. Growth of thick La{sub 2}Zr{sub 2}O{sub 7} buffer layers for coated conductors by polymer-assisted chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xin, E-mail: xzhang@my.swjtu.edu.cn [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity and New Energy Center (SNEC), Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Electrical Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhao, Yong, E-mail: yzhao@swjtu.edu.cn [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity and New Energy Center (SNEC), Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Xia, Yudong [State Key Lab of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Guo, Chunsheng [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity and New Energy Center (SNEC), Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C.H. [School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Zhang, Yong [Key Laboratory of Magnetic Levitation Technologies and Maglev Trains, Ministry of Education of China, Superconductivity and New Energy Center (SNEC), Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhang, Han [Department of Physics, Peking University, Beijing 100871 (China)

    2015-06-15

    Highlights: • We develops a low-cost and high-efficient technology of fabricating LZO buffer layers. • Sufficient thickness LZO buffer layers have been obtained on NiW (2 0 0) alloy substrate. • Highly biaxially textured YBCO thin film has been deposited on LZO/NiW. - Abstract: La{sub 2}Zr{sub 2}O{sub 7} (LZO) epitaxial films have been deposited on LaAlO{sub 3} (LAO) (1 0 0) single-crystal surface and bi-axially textured NiW (2 0 0) alloy substrate by polymer-assisted chemical solution deposition, and afterwards studied with XRD, SEM and AFM approaches. Highly in-plane and out-of-plane oriented, dense, smooth, crack free and with a sufficient thickness (>240 nm) LZO buffer layers have been obtained on LAO (1 0 0) single-crystal surface; The films deposited on NiW (2 0 0) alloy substrate are also found with high degree in-plane and out-of-plane texturing, good density with pin-hole-free, micro-crack-free nature and a thickness of 300 nm. Highly epitaxial 500 nm thick YBa{sub 2}Cu{sub 3}O{sub 7−x} (YBCO) thin film exhibits the self-field critical current density (Jc) reached 1.3 MA/cm{sup 2} at 77 K .These results demonstrate the LZO epi-films obtained with current techniques have potential to be a buffer layer for REBCO coated conductors.

  7. BIODEGRADABLE COATING FROM AGATHIS ALBA

    Directory of Open Access Journals (Sweden)

    NORYAWATI MULYONO

    2012-11-01

    Full Text Available The adhesive property of copal makes it as a potential coating onto aluminum foil to replace polyethylene. This research aimed to develop copal-based coating. The coating was prepared by extracting the copal in ethyl acetate and dipping the aluminium foil in ethyl acetate soluble extract of copal. The characterization of coating included its thickness, weight, thermal and chemical resistance, and biodegradation. The results showed that the coating thickness and weight increased as the copal concentration and dipping frequency increased. Thermal resistance test showed that the coating melted after being heated at 110°C for 30 min. Copal-based coating wasresistant to acidic solution (pH 4.0, water, and coconut oil, but was deteriorated in detergent 1% (w/v and basic solution (pH 10.0. Biodegradability test using Pseudomonas aeruginosa showed weight reduction of 76.82% in 30 days.

  8. A novel corrosion and abrasion resistant internal coating method with improved adhesion using hollow cathode PECVD (Plasma Enhanced Chemical Vapor Deposition) technology

    Energy Technology Data Exchange (ETDEWEB)

    Boardman, B.; Boinapally, K.; Casserly, T.; Upadhyaya, D.; Gupta, M.; Dornfest, C. [SubOne Technology, Pleasanton, CA (United States)

    2008-07-01

    A new enabling technology for coating the internal surfaces of pipes with a hard, corrosion, wear resistant diamond-like-carbon (DLC) coating is described. The importance of proper surface preparation and optimized interface and adhesion layer is shown. Corrosion resistance is measured based on exposure to HCl, NaCl environments and autoclave with H{sub 2}S. Mechanical properties include high hardness, high adhesion, and excellent wear resistance including sand abrasion resistance. The coating is optimized for high hardness and deposition rate based on selection on the proper hydrocarbon precursor. This new technology enables wide spread use of DLC based coating to increase component life in applications where internal surface of pipes are exposed to corrosive and abrasive environment especially in the oil and gas industry. (author)

  9. Mixed zirconia calcium phosphate coatings for dental implants: Tailoring coating stability and bioactivity potential

    Energy Technology Data Exchange (ETDEWEB)

    Pardun, Karoline [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Treccani, Laura, E-mail: treccani@uni-bremen.de [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Volkmann, Eike [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany); Streckbein, Philipp [University Hospital, Justus-Liebig-University Giessen, Department of Cranio-Maxillo-Facial Surgery, Klinikstrasse 33, 35385 Giessen (Germany); Heiss, Christian [University Hospital of Giessen-Marburg, Department of Trauma Surgery, Rudolf-Buchheim-Strasse 7, 35385 Giessen, Germany, (Germany); Laboratory of Experimental Surgery, Kerkraderstrasse 9, 35392 Giessen (Germany); Destri, Giovanni Li; Marletta, Giovanni [Laboratory for Molecular Surfaces and Nanotechnology (LAMSUN), Department of Chemistry, University of Catania and CSGI, Viale A. Doria 6, 95125 Catania (Italy); Rezwan, Kurosch [University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen (Germany)

    2015-03-01

    Enhanced coating stability and adhesion are essential for long-term success of orthopedic and dental implants. In this study, the effect of coating composition on mechanical, physico-chemical and biological properties of coated zirconia specimens is investigated. Zirconia discs and dental screw implants are coated using the wet powder spraying (WPS) technique. The coatings are obtained by mixing yttria-stabilized zirconia (TZ) and hydroxyapatite (HA) in various ratios while a pure HA coating served as reference material. Scanning electron microscopy (SEM) and optical profilometer analysis confirm a similar coating morphology and roughness for all studied coatings, whereas the coating stability can be tailored with composition and is probed by insertion and dissections experiments in bovine bone with coated zirconia screw implants. An increasing content of calcium phosphate (CP) resulted in a decrease of mechanical and chemical stability, while the bioactivity increased in simulated body fluid (SBF). In vitro experiments with human osteoblast cells (HOB) revealed that the cells grew well on all samples but are affected by dissolution behavior of the studied coatings. This work demonstrates the overall good mechanical strength, the excellent interfacial bonding and the bioactivity potential of coatings with higher TZ contents, which provide a highly interesting coating for dental implants. - Highlights: • Different ratios of zirconia (TZ) and calcium phosphate (CP) were deposited on zirconia substrates. • Enhancement of TZ content in mixed coatings increased coating stability. • Enhancement of CP content in mixed coatings increased bioactivity. • All tested coating compositions were non-toxic.

  10. Mixed zirconia calcium phosphate coatings for dental implants: Tailoring coating stability and bioactivity potential

    International Nuclear Information System (INIS)

    Enhanced coating stability and adhesion are essential for long-term success of orthopedic and dental implants. In this study, the effect of coating composition on mechanical, physico-chemical and biological properties of coated zirconia specimens is investigated. Zirconia discs and dental screw implants are coated using the wet powder spraying (WPS) technique. The coatings are obtained by mixing yttria-stabilized zirconia (TZ) and hydroxyapatite (HA) in various ratios while a pure HA coating served as reference material. Scanning electron microscopy (SEM) and optical profilometer analysis confirm a similar coating morphology and roughness for all studied coatings, whereas the coating stability can be tailored with composition and is probed by insertion and dissections experiments in bovine bone with coated zirconia screw implants. An increasing content of calcium phosphate (CP) resulted in a decrease of mechanical and chemical stability, while the bioactivity increased in simulated body fluid (SBF). In vitro experiments with human osteoblast cells (HOB) revealed that the cells grew well on all samples but are affected by dissolution behavior of the studied coatings. This work demonstrates the overall good mechanical strength, the excellent interfacial bonding and the bioactivity potential of coatings with higher TZ contents, which provide a highly interesting coating for dental implants. - Highlights: • Different ratios of zirconia (TZ) and calcium phosphate (CP) were deposited on zirconia substrates. • Enhancement of TZ content in mixed coatings increased coating stability. • Enhancement of CP content in mixed coatings increased bioactivity. • All tested coating compositions were non-toxic

  11. Synthesis and Consolidation of Nano-Sized Cu Coated SiC Powders by a Chemical Method and Spark Plasma Sintering.

    Science.gov (United States)

    Jeong, Young-Keun; Bang, Su-Ryong; Oh, Sung-Tag

    2016-02-01

    Cu-70 vol% SIC composites with dense microstructure and sound interface between Cu and SIC grains were fabricated by solution chemistry route and spark plasma sintering. Two methods for developing powder mixtures of Cu and uncoated or pre-coated SIC were compared on the basis of the resulting microstructures. The pre-coating of Si(Al)OC onto SiC powders was prepared by curing and pyrolysis of Al-modified polycarbosilane. SiC/Cu composites were obtained by hydrogen reduction and densified using spark plasma sintering of pre-coated SIC and Cu-nitrate powder mixtures. The powder mixture showed a homogenous dispersion of nano-sized Cu particles on the surface of SIC powers. Microstructural observation revealed that the sintered composite using powder mixture with pre-coating of Al-PCS onto SiC powders showed dense microstructure and good contact between Cu and SIC grains due to the improved wettability by barrier coating. The results suggested that the SiC/Cu composite with required microstructural characteristics can be fabricated by using Al-PCS coated SIC powder mixture, more effectively. PMID:27433715

  12. Drastically Enhanced High-Rate Performance of Carbon-Coated LiFePO4 Nanorods Using a Green Chemical Vapor Deposition (CVD) Method for Lithium Ion Battery: A Selective Carbon Coating Process.

    Science.gov (United States)

    Tian, Ruiyuan; Liu, Haiqiang; Jiang, Yi; Chen, Jiankun; Tan, Xinghua; Liu, Guangyao; Zhang, Lina; Gu, Xiaohua; Guo, Yanjun; Wang, Hanfu; Sun, Lianfeng; Chu, Weiguo

    2015-06-01

    Application of LiFePO4 (LFP) to large current power supplies is greatly hindered by its poor electrical conductivity (10(-9) S cm(-1)) and sluggish Li+ transport. Carbon coating is considered to be necessary for improving its interparticle electronic conductivity and thus electrochemical performance. Here, we proposed a novel, green, low cost and controllable CVD approach using solid glucose as carbon source which can be extended to most cathode and anode materials in need of carbon coating. Hydrothermally synthesized LFP nanorods with optimized thickness of carbon coated by this recipe are shown to have superb high-rate performance, high energy, and power densities, as well as long high-rate cycle lifetime. For 200 C (18s) charge and discharge, the discharge capacity and voltage are 89.69 mAh g(-1) and 3.030 V, respectively, and the energy and power densities are 271.80 Wh kg(-1) and 54.36 kW kg(-1), respectively. The capacity retention of 93.0%, and the energy and power density retention of 93.6% after 500 cycles at 100 C were achieved. Compared to the conventional carbon coating through direct mixing with glucose (or other organic substances) followed by annealing (DMGA), the carbon phase coated using this CVD recipe is of higher quality and better uniformity. Undoubtedly, this approach enhances significantly the electrochemical performance of high power LFP and thus broadens greatly the prospect of its applications to large current power supplies such as electric and hybrid electric vehicles. PMID:25970716

  13. Facile, soot free approach toward synthesis of carbon nanoropes via chemical vapor deposition of acetylene in the presence of MnFe2O4 coated on stainless steel

    Science.gov (United States)

    Dhand, Vivek; Bharadwaj, S.; Amareshwari, K.; Himabindu, V.; Rhee, Kyong Yop; Park, Soo-Jin; Hui, David

    2015-12-01

    High density, soot free, novel and a facile approach toward synthesis of carbon nanoropes (CNRs) were successfully carried out in a chemical vapor deposition (CVD) process. Manganese ferrite (MnFe2O4) coated on stainless steel foil (SS 316 grade) was used as a catalyst to initiate the growth of CNR. The coated catalyst was introduced into the CVD and the chamber temperature was set at 700 °C later followed with the release of acetylene (50 sccm) and nitrogen (500 sccm) gas, respectively. Total reaction continued until 30 min. No purification or oxidation process of the soot was involved. Analysis reveals the presence of intermingled CNRs with semi crystalline nature of the sample. The elemental analysis confirms the presence of manganese and iron whereas Raman spectrum shows the characteristic narrow G and D bands. The sample displays a super-paramagnetic behavior and is thermally stable up to 500-550 °C presenting a strong exothermic reaction.

  14. Studies on Preparation and Physico-chemical Properties of Coating-agent for Controlled Release Fertilizer%控释肥包衣剂的制备及理化性质研究

    Institute of Scientific and Technical Information of China (English)

    刘英; 熊海蓉; 祝友; 熊远福; 李霞; 刘俊

    2013-01-01

      为了获得控释肥包衣剂的制备条件、探明其理化性质,以2种树脂为成膜材料,探讨了成膜材料复合比、成膜材料用量、增塑剂用量、乳化剂用量等单因素对控释肥包衣剂制备效果的影响,运用正交试验L9(34)确定了控释肥包衣剂制备的最佳条件;并对其pH、粘度、成膜时间、成膜性、衣膜水溶性、包衣均匀度、包衣脱落率等理化性质进行了测定。结果表明,控释肥包衣剂的最佳制备条件:树脂JZ与BZ复合比1:1.5,成膜材料用量12%,增塑剂用量0.8%,乳化剂用量1.0%,色素用量0.08%,乙酸乙酯用量86.12%。理化性质测定结果显示:pH 5.21,粘度为21.1 MPa/s,成膜性良好,衣膜不溶于水,成膜时间为6 min,包衣均匀度95%,包衣脱落率<8%,表明所制备的控释肥包衣剂理化性质良好。%To obtain the preparation conditions and explore the physico-chemical properties of coating-agent for controlled release fertilizer, the single factor tests of the composite ratio of film-forming materials, the amount of film-forming materials, plasticizer, emulsifier and pigment were made with two resins as the film-forming materials, and the optimal preparation conditions of coating-agent for controlled-fertilizer were determined by orthogonal test L9(34). The physico-chemical properties of the pH, viscosity, film-forming time, film-forming properties, water solubility of coated film, coating uniformity, coating-off rate were measured. The results showed that, the optimal preparation conditions were as follows:the composite ratio (JZ:BZ) was 1:1.5, amount of film-forming materials was 12%, plasticizer was 0.8%, emulsifier was 1.0%, pigment was 0.08% and solvent was 86.12%. Test results of physico-chemical properties showed that, the pH was 5.21, viscosity was 21.1 MPa/s, the film was good and indissolvable in water, the film-forming time was 6 min, coating uniformity was 95%, coating

  15. 控释肥包衣剂的制备及理化性质研究%Studies on Preparation and Physico-chemical Properties of Coating-agent for Controlled Release Fertilizer

    Institute of Scientific and Technical Information of China (English)

    刘英; 熊海蓉; 祝友; 熊远福; 李霞; 刘俊

    2013-01-01

      为了获得控释肥包衣剂的制备条件、探明其理化性质,以2种树脂为成膜材料,探讨了成膜材料复合比、成膜材料用量、增塑剂用量、乳化剂用量等单因素对控释肥包衣剂制备效果的影响,运用正交试验L9(34)确定了控释肥包衣剂制备的最佳条件;并对其pH、粘度、成膜时间、成膜性、衣膜水溶性、包衣均匀度、包衣脱落率等理化性质进行了测定。结果表明,控释肥包衣剂的最佳制备条件:树脂JZ与BZ复合比1:1.5,成膜材料用量12%,增塑剂用量0.8%,乳化剂用量1.0%,色素用量0.08%,乙酸乙酯用量86.12%。理化性质测定结果显示:pH 5.21,粘度为21.1 MPa/s,成膜性良好,衣膜不溶于水,成膜时间为6 min,包衣均匀度95%,包衣脱落率<8%,表明所制备的控释肥包衣剂理化性质良好。%To obtain the preparation conditions and explore the physico-chemical properties of coating-agent for controlled release fertilizer, the single factor tests of the composite ratio of film-forming materials, the amount of film-forming materials, plasticizer, emulsifier and pigment were made with two resins as the film-forming materials, and the optimal preparation conditions of coating-agent for controlled-fertilizer were determined by orthogonal test L9(34). The physico-chemical properties of the pH, viscosity, film-forming time, film-forming properties, water solubility of coated film, coating uniformity, coating-off rate were measured. The results showed that, the optimal preparation conditions were as follows:the composite ratio (JZ:BZ) was 1:1.5, amount of film-forming materials was 12%, plasticizer was 0.8%, emulsifier was 1.0%, pigment was 0.08% and solvent was 86.12%. Test results of physico-chemical properties showed that, the pH was 5.21, viscosity was 21.1 MPa/s, the film was good and indissolvable in water, the film-forming time was 6 min, coating uniformity was 95%, coating

  16. Characterization and corrosion behavior of phytic acid coatings, obtained by chemical conversion on magnesium substrates in physiological solution; Caracterizacion y comportamiento frente a la corrosion de recubrimientos de acido fitico, obtenidos por conversion quimica, sobre substratos de magnesio en solucion fisiologica

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Alvarado, L. A.; Lomeli, M. A.; Hernandez, L. S.; Miranda, J. M.; Narvaez, L.; Diaz, I.; Garcia-Alonso, M. C.; Escudero, M. L.

    2014-10-01

    In order to improve the corrosion resistance of biodegradable magnesium and AZ31 magnesium alloy implants, a phytic acid coating has been applied on both substrates and their protective effect against corrosion has been assessed. The morphology and the chemical nature of the conversion coating were analyzed by SEM/EDX, XRD and FTIR. The spectra showed that the conversion coating was amorphous, and it was composed of Mg, O, and P on magnesium surface, along with Al, Zn and C on AZ31 alloy. The main coating components were chelate compounds formed by phytic acid and metallic ions. The corrosion resistance of bare and coated samples was evaluated by potentiodynamic polarization technique in Hank's solution at 37 degree centigrade. The results indicate that phytic acid conversion coatings provided a very effective protection to the magnesium substrates studied. (Author)

  17. Obtention, characterization and in vitro evaluation of polycaprolactone-chitosan coatings growth on chemically treated Ti6Al4V alloy; Obtencion, caracterizacion y evaluacion in vitro de recubrimientos de policaprolactona-quitosano sobre la aleacion Ti6Al4V tratada quimicamente

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Rodriguez, L. S.; Quintero Jaime, A. F.; Pena Ballesteros, D. Y.; Estupinan Duran, H. A.

    2014-07-01

    Polymeric coatings were obtained polycaprolactone-chitosan. The coatings were applied by dip-coating technique, on Ti6Al4V substrates chemically treated with NaOH solution. Based on SEM morphological analysis and infrared spectra, it was observed that the amount of polycaprolactone in the coating obtained had an effect in retaining the chitosan on the surface, associated with the emission of R-OH bond and the morphological characteristics. Impedance spectra performed on the polymeric films showed phenomena related processes adsorption of ionic species to monolayer formation on the surface. These spectra showed equally charge transfer phenomena generated by the morphological characteristics of the coatings, such as its porosity, density and homogeneity. The coated substrate was immersing in SBF solution for 8 days, allowed to observe its adsorption capacity of calcium through nucleation and precipitation of calcium phosphates, bioactive character displaying a front medium. (Author)

  18. Nanoparticle/Polymer Nanocomposite Bond Coat or Coating

    Science.gov (United States)

    Miller, Sandi G.

    2011-01-01

    This innovation addresses the problem of coatings (meant to reduce gas permeation) applied to polymer matrix composites spalling off in service due to incompatibility with the polymer matrix. A bond coat/coating has been created that uses chemically functionalized nanoparticles (either clay or graphene) to create a barrier film that bonds well to the matrix resin, and provides an outstanding barrier to gas permeation. There is interest in applying clay nanoparticles as a coating/bond coat to a polymer matrix composite. Often, nanoclays are chemically functionalized with an organic compound intended to facilitate dispersion of the clay in a matrix. That organic modifier generally degrades at the processing temperature of many high-temperature polymers, rendering the clay useless as a nano-additive to high-temperature polymers. However, this innovation includes the use of organic compounds compatible with hightemperature polymer matrix, and is suitable for nanoclay functionalization, the preparation of that clay into a coating/bondcoat for high-temperature polymers, the use of the clay as a coating for composites that do not have a hightemperature requirement, and a comparable approach to the preparation of graphene coatings/bond coats for polymer matrix composites.

  19. Oral coatings: a study on the formation, clearance and perception

    OpenAIRE

    Camacho, S

    2015-01-01

    Oral coatings are residues of food and beverages that coat the oral mucosa after consumption. Several studies have reported on the lubrication properties in mouth, and the after-feel and after-taste impact of oral coatings. Further, oral coatings have been suggested to influence subsequent taste perception. Although it is well known that oral coatings can influence sensory perception, there was little information available on the chemical composition and physical properties of oral coatings. ...

  20. Corrosion behavior of duplex coatings

    Directory of Open Access Journals (Sweden)

    K. Raghu Ram Mohan Reddy

    2016-07-01

    Full Text Available The titanium alloys are used in defense, aerospace, automobile, chemical plants and biomedical applications due to their very high strength and lightweight properties. However, corrosion is a life-limiting factor when Ti alloys are exposed to different chemical environments at high temperatures. In the present paper, duplex NiCrAlY/WC–Co coating is coated onto Ti6Al4V substrate to investigate the corrosion behavior of both coated samples and the substrate. The duplex coating was performed with NiCrAlY as the intermediate coat of 200 μm thickness deposited by HVOF process and WC–Co ceramic top coat with varying thicknesses of 250 μm, 350 μm and 450 μm deposited by DS process. Potentiodynamic polarization tests were employed to investigate the corrosion performance of duplex coated samples and substrate in Ringer’s solution at 37 °C and pH value was set to 5.7. Finally the results reveal that 350 μm thick coated samples showed highest corrosion resistance compared to 250 μm thick samples as well as bare substrate. However, the 450 μm thick coated sample showed poor corrosion resistance compared to the substrate. The scale formed on the samples upon corrosion was characterized by using SEM analysis to understand the degree of corrosion behavior.

  1. Investigation of passive and active silica-tin oxide nanostructured optical fibers fabricated by " inverse dip-coating " and " powder in tube " method based on the chemical sol-gel process and laser emission

    OpenAIRE

    Granger, Geoffroy; Restoin, Christine; Roy, Philippe; Jamier, Raphaël; Rougier, Sébastien; Duclere, J.-R; Lecomte, A; Dauliat, Romain; Blondy, Jean-Marc

    2015-01-01

    International audience This paper presents a study of original nanostructured optical fibers based on the SiO 2-SnO 2-(Yb 3+) system. Two different processes have been developed and compared: the sol-gel chemical method associated to the " inverse dip-coating " (IDC) and the " powder in tube " (PIT) process. The microstructural and optical properties of the fibers are studied according to the concentration of SnO 2. X-Ray Diffraction as well as Transmission Electron Microscopy studies show...

  2. Deposition and Coating Properties on CVD Tungsten

    Institute of Scientific and Technical Information of China (English)

    DU Ji-hong; LI Zheng-xiang; LIU Gao-jian; ZHOU Hui-Huang; CHUN liang

    2004-01-01

    Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.

  3. Are PEI-coated SWCNTs conjugated with hepatitis A virus? A chemical study with SEM, Z-potential, EDXD and RT-PCR

    Energy Technology Data Exchange (ETDEWEB)

    Carbone, M; Valentini, F; Palleschi, G [Dip. Scienze e Tecnologie Chimiche, Universita Tor Vergata, via della Ricerca Scientifica 1, 00133 Roma (Italy); Caminiti, R [Department of Chemistry, University of ' La Sapienza' , P.le A. Moro 5, 00185, Roma (Italy); Petrinca, A R; Donia, D; Divizia, M, E-mail: marilena.carbone@roma2.infn.i, E-mail: federica.valentini@uniroma2.i [Department of Public Health, Hygiene chair, University of Tor Vergata, Via Montpellier, n. 1, 00133 Roma (Italy)

    2010-06-01

    The conjugation between nanotubes, coated with different doses of polyethylene imine (PEI) and hepatitis A virus (HAV) was investigated by scanning electron microscopy, Z-potential, thermogravimetric and differential thermal analysis, transmission electron microscopy, energy dispersive x-ray diffraction (EDXD) and reverse transcript polymerase chain reaction (RT-PCR). For the first time, to our knowledge, evidence is obtained that conjugation between the nanotubes and the HAV occurs and that it has an (at least a partial) electrostatic character. Since all components of the conjugated systems, nanotubes, coating material and virus are characterized by different peak shapes in the selected q range, it was possible to infer that conjugation occurred. RT-PCR measurements confirmed that the conjugation of the coated nanotubes and HAV occurred and the result was stable. This opens up the prospect of probing the coated nanotubes as intra-cellular carriers in transfection processes of the virus. Further biological applications will concern a possible vaccine especially for non-replicative viruses.

  4. Co3O4 protective coatings prepared by Pulsed Injection Metal Organic Chemical Vapour Deposition

    DEFF Research Database (Denmark)

    Burriel, M.; Garcia, G.; Santiso, J.;

    2005-01-01

    deposition temperature. Pure Co3O4 spinel structure was found for deposition temperatures ranging from 360 to 540 degreesC. The optimum experimental parameters to prepare dense layers with a high growth rate were determined and used to prepare corrosion protective coatings for Fe-22Cr metallic interconnects...

  5. Morbus Coats

    Science.gov (United States)

    Förl, B.; Schmack, I.; Grossniklaus, H.E.; Rohrschneider, K.

    2010-01-01

    Der fortgeschrittene Morbus Coats stellt im Kleinkindalter eine der schwierigsten Differenzialdiagnosen zum Retinoblastom dar. Wir beschreiben die klinischen und histologischen Befunde zweier Jungen im Alter von 9 und 21 Monaten mit einseitiger Leukokorie. Trotz umfassender Diagnostik mittels Narkoseuntersuchung, MRT und Ultraschall konnte ein Retinoblastom nicht sicher ausgeschlossen werden, und es erfolgte eine Enukleation. Histologisch wurde die Diagnose eines Morbus Coats gesichert. Da eine differenzialdiagnostische Abgrenzung zwischen Morbus Coats und Retinoblastom schwierig sein kann, halten wir in zweifelhaften Fällen auch angesichts der eingeschränkten Visusprognose und potenzieller Sekundärkomplikationen beim fortgeschrittenen Morbus Coats eine Enukleation für indiziert. PMID:18299842

  6. 复合型缓释肥包衣剂理化性质及缓释特性研究%Studies on Physical and Chemical Properties and Slow- Release Properties of Compound Coating Agent for Slow-Release Fertilizer

    Institute of Scientific and Technical Information of China (English)

    熊海蓉; 钟总; 官春云; 蒋利华; 邹应斌; 熊远福

    2011-01-01

    为了探明复合型缓释肥包表剂的理化性质及其缓释特性,对复合型缓释肥包衣剂的粘度、成膜性、成膜时间、膜韧性、包衣脱落率、包衣肥的养分初期溶出率、养分微分溶出率、养分累积释放曲线等进行了测定.理化性质测试结果显示:缓释肥包衣剂的粘度为44.5 MPa/s、成膜性良好、成膜时间7min、包衣膜拉长倍数达2.8倍,包衣脱落率<5%.缓释特性测试结果显示:包衣肥养分N、P、K初期溶解率<15%、微分溶解率<2%,符合中国缓释肥料标准GB/T23348-2009.其中P的初期溶解率小于N、K的初期溶解率,而N、P、K微分溶解率相差不大.养分累积释放曲线大致呈“S”型,与作物生长需肥规律一致.表明复合型缓释肥包衣剂的理化性质良好,能有效控制普通复合肥养分的缓释.%To explore the physical and chemical properties and slow-release properties of compound coating-agent for slow-release fertilizer (KSFF-2), the viscosity, forming film property, forming film time, film tenacity, coating off rates of coating agent, and the nutrient initial-release ratios, nutrient micro-release ratios and nutrient accumulation-release curves of coating slow-release fertilizer were determined. Results showed that the viscosity of the compound coating-agent was 44.5 Mpa/s, forming film property was better, forming film time was 7 min, film stretch ratio was 2.8 times, coating off rates was less than 5%. The initial release ratio of N, P, K in the coated fertilizer was less than 15%, the micro release ratio was less than 2%, which was consistent with the slow-release fertilizer standard GB/T 23348-2009 constituted by China. The initial dissolution rate of P was less than those of N and K, and the micro release ratio of N, P, K was almost the same. The nutrient accumulation-release curves were S-shape, which was consistent with the nutrient demand of crops. These results indicated the physical and chemical

  7. Coating based Fiber Bragg Grating humidity sensor array

    NARCIS (Netherlands)

    Cheng, L.K.; Boersma, A.; Jansen, T.H.

    2012-01-01

    A coating based FBG humidity sensor is developed for distributed humidity sensing. The sensitivity of the coated FBG is optimized by varying the chemical composition and the thickness of the coating. A sensitivity of ~2 pm/%RH and a rapid response are demonstrated. The composition of the coating can

  8. Deposition and mechanical properties of Ti-Si-N coated layer on WC-Co by RF inductively coupled plasma-enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eung-Ahn; Kim, Kwang Ho

    2002-12-02

    Coatings of Ti-Si-N on WC-Co substrates were deposited by an r.f. inductively coupled (RFI) PECVD technique. Ti-Si-N coating layers were grown with fairly high deposition rates, and had a maximum hardness value of 38-40 GPa when deposited at 500-600 deg. C with a Si content of approximately 10 at.%. The film microstructure of maximum hardness was revealed to be a nanocomposite of nano-sized TiN crystallites embedded in amorphous silicon nitride phase by high resolution transmission electron microscopy (HRTEM). The increase of Si content above 10 at.% caused thickening of amorphous silicon nitride phase and an appearance of free Si, although increasing Si also induced finer and more isotropic TiN crystallites with full percolation by amorphous phase. The deposition behaviors of Ti-Si-N, their microstructures, and mechanical property by an RFI-PECVD method were systematically investigated in this work.

  9. Deposition and mechanical properties of Ti-Si-N coated layer on WC-Co by RF inductively coupled plasma-enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    Coatings of Ti-Si-N on WC-Co substrates were deposited by an r.f. inductively coupled (RFI) PECVD technique. Ti-Si-N coating layers were grown with fairly high deposition rates, and had a maximum hardness value of 38-40 GPa when deposited at 500-600 deg. C with a Si content of approximately 10 at.%. The film microstructure of maximum hardness was revealed to be a nanocomposite of nano-sized TiN crystallites embedded in amorphous silicon nitride phase by high resolution transmission electron microscopy (HRTEM). The increase of Si content above 10 at.% caused thickening of amorphous silicon nitride phase and an appearance of free Si, although increasing Si also induced finer and more isotropic TiN crystallites with full percolation by amorphous phase. The deposition behaviors of Ti-Si-N, their microstructures, and mechanical property by an RFI-PECVD method were systematically investigated in this work

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

    Science.gov (United States)

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

    2003-05-01

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

  11. Effects of post-deposition annealing on the mechanical and chemical properties of the Si3N4/NbN multilayer coatings

    International Nuclear Information System (INIS)

    Multilayered thin films consisting of alternate layers of silicon nitride (Si3N4) and niobium nitride (NbN) have been prepared by a dc reactive sputtering technique in nitrogen and argon atmosphere using high purity Nb and Si targets for various flow ratios of N2/Ar. It has been found that the hardness of the multilayered system is higher than that of the constituent individual layers of equal thickness. Although a single layer of amorphous Si3N4 has higher hardness compared with a single layer of nanocrystalline NbN at all the deposition conditions used in this experiment, the hardness of the multilayer coatings consisting of consecutive Si3N4/NbN layers strongly follows the hardness variation of the polycrystalline NbN. When the multilayer coatings are subjected to post-deposition annealing at high temperatures, it has been found that both the hardness and the adhesion strength of the coating decrease with increasing annealing temperature. X-ray photoelectron spectroscopy (XPS) results reveal that oxidation of the coatings during annealing plays a crucial role behind such deterioration in mechanical properties. Further, it has been noted that NbN is a more oxidation resistant material than Si3N4. Therefore, it has been proposed that during preparation of multilayers with consecutive thin layers of NbN and Si3N4, the topmost layer should be made of NbN, instead of Si3N4, to prevent the oxygen diffusion from the top surface layer to the next layer underneath

  12. In Vitro Corrosion and Cytocompatibility of ZK60 Magnesium Alloy Coated with Hydroxyapatite by a Simple Chemical Conversion Process for Orthopedic Applications

    OpenAIRE

    Bing Wang; Ping Huang; Caiwen Ou; Kaikai Li; Biao Yan; Wei Lu

    2013-01-01

    Magnesium and its alloys—a new class of degradable metallic biomaterials—are being increasingly investigated as a promising alternative for medical implant and device applications due to their advantageous mechanical and biological properties. However, the high corrosion rate in physiological environments prevents the clinical application of Mg-based materials. Therefore, the objective of this study was to develop a hydroxyapatite (HA) coating on ZK60 magnesium alloy substrates to mediate th...

  13. Investigation of mechanically hard, chemically inert antireflection coatings for photovoltaic solar modules. Final technical report, April 1, 1980-March 31, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Moravec, T.J.

    1981-03-31

    The overall objective of this program is to determine the optical properties of i-Carbon (diamond-like) films and determine if these films can be developed into antireflecting (AR) coatings for silicon solar cells. The i-C films have been produced on glass, silicon, and KCl by radio frequency (RF) plasma decomposition of the alkane gases. Films were also produced on silicon solar cells by low-energy ion beam techniques. These coatings did not perform as well as those made from hydrocarbon gases. Significant progress has been made in understanding the deposition parameters that affect the optical properties of the films. The optical constants n and k have been determined over a large range of process parameters and source gas. The degree of hydrogen incorporation in these films has been studied by SIMS analysis. It was found that the lower optically absorbing films contain more hydrogen. This hydrogen does not, however, manifest itself in fundamental C-H absorption bands in the infrared. Very efficient single-layer quarter-wave i-C AR coatings have been produced on single-crystal and SOC Si solar cells. An increase in cell efficiency of 40% over uncoated cells has been achieved.

  14. A high-sensitivity chemical sensor based on titania coated optical-fiber long period grating for ammonia sensing in water

    Science.gov (United States)

    Tiwari, D.; James, S. W.; Tatam, R. P.; Korposh, S.; Lee, S. W.

    2015-07-01

    Two highly sensitive ammonia sensors, formed by depositing coatings composed of titanium dioxide (TiO2) onto the cladding of an optical fibre sensing platform, are evaluated. A long period grating (LPG) of period 111 μm was fabricated in the core of an optical fibre so that the LPG operates at or near the phase matching turning point (PMTP). The first coating that was investigated was composed of TiO2 nanoparticles deposited by liquid phase deposition. The sensor showed high sensitivity and allowed low concentrations of ammonia in water (0.01 ppm) to be detected with a response time of less than 60 sec. The second coating was composed of TiO2 with subsequent layers of poly (allyamine hydrochloride) (PAH), and SiO2 nanospheres infused with a sensitive element composed of porphine. The ammonia adsorption to the porphine compound led to the changes in the LPG's transmission spectrum and allowed 0.1 ppm of ammonia in water to be detected with a response time of less than 60 sec.

  15. Physical and Chemical Properties and Safety Study of Six Corn Seed-coatings to Maize%6种玉米种衣剂的理化性质测定及其安全性研究

    Institute of Scientific and Technical Information of China (English)

    王斌; 张婧赢; 王岩; 郑逢云; 刘三明

    2011-01-01

    To better understand the quality of corn seed-coatings, physical and chemical properties and safety of six corn seed-coatings were tested.Film-forming, Coating homogeneity and suspension rate of all coatings met the national standards.Viscosity values of 15.5% Thiram · Carbofuran and 8.1% Carbofuran ·Tebuconazole· Triadimenfon reached the national standards.pH ranges of all seed coatings occurred between 6.38 and 7.55, and 25% Carbofuran· Thiram· Carboxin, 15% Thiram· Carbofuran· Tebuconazole and 20% Thiram· Carbofuran · Triadimenal came up to the National Standards.Pull-out rate of seed coatings met the national standards excerpt 25% Carbofuran· Thiram· Carboxin.Germination potential, germination rate,germination index, date of seedling vigor index, seedling length and fresh weight of seeds treated with seed coating were lower than the control in Laboratory.Seedling emergency rates of all treatments in field trail were improved comparing with the control, but seedling quality had no significant increase.The results showed that 15.5% Thiram· Carbofuran is the best choice among the six corn seed-coatings.%为了解市场上玉米种衣剂的质量,对6种市售玉米种衣剂的理化性质和安全性进行了测定.理化性质表明:6种种衣剂的成膜时间、包衣均匀度和悬浮率都符合国家标准;不同种衣剂粘度值差异显著,只有福·克和克·戊·三唑酮符合国家标准;pH都在6.83~7.55之间,其中克·福·萎、福·克·唑醇和克·醇·福美双符合国家标准;包衣脱落率只有克·福·萎大于10%,其它药剂均达到国家标准.室内发芽实验表明:经玉米种衣剂处理后,玉米种子活力等各项指标均低于对照;而田间实验表明:种衣剂处理后,玉米出苗率、幼苗素质与对照相比都有所提高,其中福·克效果最为显著.从室内、田间的实验结果分析,福·克是6种玉米种衣剂中的最佳选择.

  16. Sprayed coatings

    Science.gov (United States)

    Steffens, H. D.

    1980-03-01

    Thermal spraying is shown to be an efficient means for the protection of surface areas against elevated temperature, wear, corrosion, hot gas corrosion, and erosion in structural aircraft components. Particularly in jet engines, numerous parts are coated by flame, detonation, or plasma spraying techniques. The applied methods of flame, detonation, and plasma spraying are explained, as well as electric arc spraying. Possibilities for spray coatings which meet aircraft service requirements are discussed, as well as methods for quality control, especially nondestructive test methods. In particular, coating characteristics and properties obtained by different spray methods are described, and special attention is paid to low pressure plasma spraying.

  17. Nanocrystalline Ni-W coatings on copper

    Energy Technology Data Exchange (ETDEWEB)

    Panagopoulos, C.N., E-mail: chpanag@metal.ntua.gr [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780, Athens (Greece); Plainakis, G.D.; Lagaris, D.A. [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780, Athens (Greece)

    2011-04-15

    Nanocrystalline Ni-W coatings were produced on copper substrates with the aid of electrodeposition technique. The morphology, chemical composition and structure of the produced coatings were examined with the aid of scanning electron microscopy (SEM), electron dispersive spectroscopy (EDS) and X-ray diffraction (XRD) techniques. The microhardness of alloy Ni-W coatings on copper substrate was also studied. The adhesion between the Ni-W coating, having W content 50 wt%, and the copper substrate, was also studied with a scratch testing apparatus. The scratch tests resulted in the coatings suffering an intensive brittle fracture and minor delamination.

  18. Spectroscopic and ultrastructural analysis of fluorhydroxyapatite-coated titanium plates

    Energy Technology Data Exchange (ETDEWEB)

    Martini, D.; Ottani, V.; Ruggeri, A. [Bologna Univ. (Italy). Dipt. di Scienze Anatomiche e Fisiopatologia dell' Apparato Locomotore; Raspanti, M. [Insubria Univ. (Italy). Dipt. di Scienze Cliniche e Biologiche; Monti, P.; Taddei, P.; Tinti, A.; Fragnano, C. [Bologna Univ. (Italy). Dipt. di Biochimica ' G. Moruzzi'

    2001-07-01

    This study aimed to describe the chemical, physical and morphological features of the surface of titanium plates coated with porous titanium and fluorhydroxyapatite for surgical implantation. Although the plasma flame spray coating process partially altered the original chemical and physical characteristics of the coatings, the surface morphology of the coated plates seems very favourable for bone integration of the implant. Immersion in simulated body fluid for ten weeks failed to disclose signs of implant dissolution or impaired surface composition. (orig.)

  19. Use of polyurea from urea for coating of urea granules

    OpenAIRE

    Lu, Panfang; Zhang, Yanfei; Jia, Cong; Li, Yufeng; Mao, Zhiquan

    2016-01-01

    A new type of controlled release fertilizers coated with polyurea was prepared. The granulated urea was firstly changed into a liquid urea by heating as the coating liquid. By spraying uniformly the urea was coated with the polyurea synthesized by the reaction of isocyanates with a liquid urea. The effects of different modifiers on N release characteristics of polyurea-coated urea (PCU) were studied. The morphology and chemical structure of PCU coating materials was investigated by SEM and FT...

  20. Hard coatings

    OpenAIRE

    Dan, J.; Boving, H.; Hintermann, H.

    1993-01-01

    Hard, wear resistant and low friction coatings are presently produced on a world-wide basis, by different processes such as electrochemical or electroless methods, spray technologies, thermochemical, CVD and PVD. Some of the most advanced processes, especially those dedicated to thin film depositions, basically belong to CVD or PVD technologies, and will be looked at in more detail. The hard coatings mainly consist of oxides, nitrides, carbides, borides or carbon. Over the years, many process...

  1. Mixed zirconia calcium phosphate coatings for dental implants: tailoring coating stability and bioactivity potential.

    Science.gov (United States)

    Pardun, Karoline; Treccani, Laura; Volkmann, Eike; Streckbein, Philipp; Heiss, Christian; Li Destri, Giovanni; Marletta, Giovanni; Rezwan, Kurosch

    2015-03-01

    Enhanced coating stability and adhesion are essential for long-term success of orthopedic and dental implants. In this study, the effect of coating composition on mechanical, physico-chemical and biological properties of coated zirconia specimens is investigated. Zirconia discs and dental screw implants are coated using the wet powder spraying (WPS) technique. The coatings are obtained by mixing yttria-stabilized zirconia (TZ) and hydroxyapatite (HA) in various ratios while a pure HA coating served as reference material. Scanning electron microscopy (SEM) and optical profilometer analysis confirm a similar coating morphology and roughness for all studied coatings, whereas the coating stability can be tailored with composition and is probed by insertion and dissections experiments in bovine bone with coated zirconia screw implants. An increasing content of calcium phosphate (CP) resulted in a decrease of mechanical and chemical stability, while the bioactivity increased in simulated body fluid (SBF). In vitro experiments with human osteoblast cells (HOB) revealed that the cells grew well on all samples but are affected by dissolution behavior of the studied coatings. This work demonstrates the overall good mechanical strength, the excellent interfacial bonding and the bioactivity potential of coatings with higher TZ contents, which provide a highly interesting coating for dental implants. PMID:25579931

  2. Ruthenium recovery from acetic acid industrial effluent using chemically stable and high-performance polyethylenimine-coated polysulfone-Escherichia coli biomass composite fibers.

    Science.gov (United States)

    Kim, Sok; Choi, Yoon-E; Yun, Yeoung-Sang

    2016-08-01

    Recovery of precious metal ions from waste effluents is of high concern. In general, ruthenium (Ru) is used in the Cativa process as promoter for carbonylation catalyst and discharged into acetic acid effluent. In the present work, we have designed and developed polyethylenimine-coated polysulfone-bacterial biomass composite fiber (PEI-PSBF) to recover Ru from industrial effluent. The sorbent was manufactured by electrostatic attachment of polyethylenimine (PEI) to the surface of polysulfone-biomass composite fiber (PSBF), which was prepared through spinning of the mixture of polysulfone and Escherichia coli biomass in N,N-dimethylformamide (DMF) into water. Developed PEI-PSBF was highly stable in the acetic acid effluent. The maximum sorption capacity of the developed sorbent PEI-PSBF, coated with PEI (with M.W. of 75,000), was 121.28±13.15mg/g, which was much higher than those of ion exchange resins, TP214, Amberjet 4200, and M500. The PEI-PSBF could be successfully applied in the flow-through column system, showing 120 beds of breakthrough volume. PMID:27045623

  3. An all chemical solution deposition approach for the growth of highly textured CeO2 cap layers on La2Zr2O7-buffered long lengths of biaxially textured Ni-W substrates for YBCO-coated conductors

    International Nuclear Information System (INIS)

    A reel-to-reel, dip coating process has been developed to continuously deposit epitaxial La2Zr2O7 (LZO) and CeO2 on 5 m long cube-textured {100} (001)Ni tapes. Recent results for La2Zr2O7 and CeO2 buffer layers deposited on long lengths of Ni substrate for the realization of YBa2Cu3O7-x (YBCO)-coated conductors are presented. The major achievement is the development of a new all chemical solution deposition (CSD) process leading to the formation of highly textured buffer layers at moderate annealing temperatures. Reproducible highly textured, dense and crack-free LZO buffer layers and CeO2 cap layers were obtained for annealing temperatures as low as 900 deg. C in a reducing atmosphere (Ar-5 at.%-H2). The thickness of the LZO buffer layers was determined to be (200 ± 10) nm per single coating; prepared cerium oxide layers showed a thickness of 60 nm ± 10 nm. Pulsed laser deposition (PLD) was used to grow YBCO films on these substrates. A Tc0 of T = 90.5 K and ΔTc = 1.4 K was obtained on PLD-YBCO/CSD-CeO2 /CSD-LZO/Ni-5 at.% W, which shows the outstanding features of this new buffer layer architecture processed by CSD. The large layer thickness combined with low annealing temperatures is the main advantage of this new process for low-cost buffer layer deposition on Ni-RABiTS (rolling-assisted biaxially textured substrates)

  4. Ion-stimulated Gas Desorption Yields of Electropolished, Chemically Etched, and Coated (Au, Ag, Pd, TiZrV) Stainless Steel Vacuum Chambers and St707 Getter Strips Irradiated with 4.2 MeV/u lead ions

    CERN Document Server

    Mahner, E; Küchler, D; Malabaila, M; Taborelli, M

    2005-01-01

    The ion-induced desorption experiment, installed in the CERN Heavy Ion Accelerator LINAC 3, has been used to measure molecular desorption yields for 4.2 MeV/u lead ions impacting under grazing incidence on different accelerator-type vacuum chambers. Desorption yields for H2, CH4, CO, and CO2, which are of fundamental interest for future accelerator applications, are reported for different stainless steel surface treatments. In order to study the effect of the surface oxide layer on the gas desorption, gold-, silver-, palladium-, and getter-coated 316 LN stainless steel chambers and similarly prepared samples were tested for desorption at LINAC 3 and analysed for chemical composition by X-ray Photoemission Spectroscopy (XPS). The large effective desorption yield of 2 x 104 molecules/Pb53+ ion, previously measured for uncoated, vacuum fired stainless steel, was reduced after noble-metal coating by up to 2 orders of magnitude. In addition, pressure rise measurements, the effectiveness of beam scrubbing with le...

  5. Structure and corrosion properties of PVD Cr-N coatings

    CERN Document Server

    Liu, C; Ziegele, H; Leyland, A; Matthews, A

    2002-01-01

    PVD Cr-N coatings produced by physical vapor deposition (PVD) are increasingly used for mechanical and tribological applications in various industrial sectors. These coatings are particularly attractive for their excellent corrosion resistance, which further enhances the lifetime and service quality of coated components. PVD Cr-N coated steels in an aqueous solution are usually corroded by galvanic attack via through-coating 'permeable' defects (e.g., pores). Therefore, the corrosion performance of Cr-N coated steel is determined by a number of variables of the coating properties and corrosive environment. These variables include: (i) surface continuity and uniformity; (ii) through-coating porosity; (iii) film density and chemical stability; (iv) growth stresses; (v) interfacial and intermediate layers; (vi) coating thickness; (vii) coating composition; and (viii) substrate properties. In this article, PVD Cr-N coatings were prepared, by electron-beam PVD and sputter deposition, with different compositions, t...

  6. Hard coatings

    International Nuclear Information System (INIS)

    Hard, wear resistant and low friction coatings are presently produced on a world-wide basis, by different processes such as electrochemical or electroless methods, spray technologies, thermochemical, CVD and PVD. Some of the most advanced processes, especially those dedicated to thin film depositions, basically belong to CVD or PVD technologies, and will be looked at in more detail. The hard coatings mainly consist of oxides, nitrides, carbides, borides or carbon. Over the years, many processes have been developed which are variations and/or combinations of the basic CVD and PVD methods. The main difference between these two families of deposition techniques is that the CVD is an elevated temperature process (≥ 700 C), while the PVD on the contrary, is rather a low temperature process (≤ 500 C); this of course influences the choice of substrates and properties of the coating/substrate systems. Fundamental aspects of the vapor phase deposition techniques and some of their influences on coating properties will be discussed, as well as the very important interactions between deposit and substrate: diffusions, internal stress, etc. Advantages and limitations of CVD and PVD respectively will briefly be reviewed and examples of applications of the layers will be given. Parallel to the development and permanent updating of surface modification technologies, an effort was made to create novel characterisation methods. A close look will be given to the coating adherence control by means of the scratch test, at the coating hardness measurement by means of nanoindentation, at the coating wear resistance by means of a pin-on-disc tribometer, and at the surface quality evaluation by Atomic Force Microscopy (AFM). Finally, main important trends will be highlighted. (orig.)

  7. Thermal barrier coatings: Coating methods, performance, and heat engine applications. (Latest citations from the EI Compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    The bibliography contains citations concerning conference proceedings on coating methods, performance evaluations, and applications of thermal barrier coatings as protective coatings for heat engine components against high temperature corrosions and chemical erosions. The developments of thermal barrier coating techniques for high performance and reliable gas turbines, diesel engines, jet engines, and internal combustion engines are presented. Topics include plasma sprayed coating methods, yttria stabilized zirconia coatings, coating life models, coating failure and durability, thermal shock and cycling, and acoustic emission analysis of coatings. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  8. Nanostructured Coatings

    Science.gov (United States)

    Rivière, J.-P.

    In many branches of technology where surfaces are playing a growing role, the use of coatings is often the only way to provide surfaces with specific functional properties. For example, the austenitic stainless steels or titanium alloys exhibit poor resistance to wear and low hardness values, which limits the field of applications. The idea then is to develop new solutions which would improve the mechanical performance and durability of objects used in contact and subjected to mechanical forces in hostile gaseous or liquid environments. Hard coatings are generally much sought after to enhance the resistance to wear and corrosion. They are of particular importance because they constitute a class of protective coatings which is already widely used on an industrial scale to improve the hardness and lifetime of cutting tools.

  9. 模拟危化液体储罐复合热控涂层的开发与应用%Development and application of thermal control coatings for simulated hazardous chemical liquid storage tank

    Institute of Scientific and Technical Information of China (English)

    李少香; 尹燕福; 慕常强; 李新华; 范伟建; 翟士刚

    2014-01-01

    A thermal control coating system was designed for liquid storage tank as epoxy micaceous iron oxide primer (50-60 μm) + rigid polyurethane foam thermal insulation coating+grid enforcement layer+transition layer (0.5 cm)+heat reflective topcoat (50-60 μm). The effect of the thickness of heat insulation polyurethane coating on the thermal insulation of a 20 L coated barrel was studied. The suitable thickness was determined as 5 cm, achieving the integration of corrosion protection, thermal barrier, and heat reflection. The adhesion of adjacent layers, compressive strength, high and low temperature alternating resistance,and salt spray corrosion resistance of the composite coating were tested. The thermal control performance of the simulated 13 m3 and 40 m3 chemical liquid storage tanks coated with the composite coating was examined, as compared with the fire equipment shed near the storage tanks. The results showed that the adhesions strength of the steel sheet to primer and the transition layer to the heat reflective layer are grade one, and those of the primer to the thermal insulation layer and the thermal insulation layer to the transition layer are 6.3 MPa and 5.2 MPa, respectively. The surface of the composite coating showed no bubbling and peeling in salt water resistance test and salt spray test. The composite has a compressive strength about 0.35 N/mm2, and is smooth, leveled, and crack-free after high and low temperature alternating for 10 cycles. The performance of the composite coating meets the working environment requirement of storage tanks. In thermal control property test, the temperature change of water in 13 m3 and 40 m3 storage tanks was within 4 °C when the temperature inside the fire equipment shed varied between 20 °C to 42 °C. The composite coating structure shows good thermal insulation effect.%设计了液体储罐用热控涂层结构:环氧云铁底涂(50~60μm)+聚氨酯硬泡隔热层+网格加强层+过渡层(0.5 cm

  10. Edison's vacuum coating patents

    International Nuclear Information System (INIS)

    Among the over one thousand patents bearing Thomas A. Edison's name are several for vacuum coating processes including chemical vapor deposition, evaporation, and sputter deposition. Beginning in 1880 Edison applied for patents that described carbon deposition processes that would now be called pyrolytic chemical vapor deposition. In 1884 Edison applied for a patent (granted in 1894) that described coating by evaporation in a vacuum by direct resistance heating or arc heating using a continuous current. Edison called the process 'electro vacuous deposition'. He prophetically wrote, 'the uses of the invention are almost infinite'. Edison also employed sputter deposition and in 1900 applied for a patent on a 'Process of Coating Phonograph Records'. Issued in 1902, the patent describes using a 'silent or brush electrical discharge' produced by an induction coil. The National Phonograph Company, one of Edison's many enterprises, used the sputtering process to deposit a thin layer of gold on wax phonograph cylinder masters that could then be electroplated to form molds to mass produce celluloid duplicates. The method was used for 20 years, from 1901 to 1921. It enabled the reproduction of cylinder grooves less than 0.001 in. deep at a density of 200 grooves per in. From 1913 to 1921, 10-in.-diameter Edison Diamond Disc phonograph records were made using the same method. Sputtering was abandoned in 1927, as it could not be scaled up to produce the 12 in. disks that were then introduced

  11. Study on advanced Ce0.9La0.1O2/Gd2Zr2O7 buffer layers architecture towards all chemical solution processed coated conductors

    DEFF Research Database (Denmark)

    Yue, Zhao; Ma, L.; Wu, W.;

    2015-01-01

    Chemical solution deposition is a versatile technique to deposit functional oxide films with low cost. In this study, this approach was employed to grow multi-layered, second-generation, high-temperature superconductors ("coated conductors") with high superconducting properties. The Ce0.9La0.1O2/...

  12. Selective optical coatings for solar collectors

    Science.gov (United States)

    Lowery, J. R.

    1980-01-01

    For best performance, energy-absorbing surface of solar collector should be characterized by high ratio of solar absorptance to thermal emitance. Report on optical characteristics of several chemical treatments and electrodeposited coatings for metal solar-absorbing surfaces should interest designers and users of solar-energy systems. Moisture resistance of some coatings is also reported.

  13. New chemically reworkable epoxy coatings obtained by the addition of polyesters with star topologies to diglycidyl ether of bisphenol A resins

    OpenAIRE

    Tomuta, Adrian Marius; Ramis Juan, Xavier; Fernández Francos, Xavier; Ferrando Piera, Francesc; Serra Albet, Àngels

    2013-01-01

    A new multiarm star with hyperbranched aromatic–aliphatic polyester core and poly(ɛ-caprolactone) arms (HBPCL) was synthesized and characterized. Mixtures of diglycidyl ether of bisphenol A (DGEBA) resin and different proportions of this star type modifier were cured using a thermal cationic curing agent, Yb(OTf)3. The HBPCL prepared has hydroxyl groups as chain ends, which are capable of chemically incorporating to the epoxy matrix by means of the monomer activated mechanism. This, together ...

  14. Molecularly imprinted layer-coated silica nanoparticles for selective solid-phase extraction of bisphenol A from chemical cleansing and cosmetics samples

    International Nuclear Information System (INIS)

    Highly selective molecularly imprinted layer-coated silica nanoparticles for bisphenol A (BPA) were synthesized by molecular imprinting technique with a sol-gel process on the supporter of silica nanoparticles. The BPA-imprinted silica nanoparticles were characterized by fourier transform infrared spectrometer, transmission electron microscope, dynamic adsorption and static adsorption tests. The equilibrium association constant, Ka, and the apparent maximum number of binding sites, Qmax, were estimated to be 1.25 x 105 mL μmol-1 and 16.4 μmol g-1, respectively. The BPA-imprinted silica nanoparticles solid-phase extraction (SPE) column had higher selectivity for BPA than the commercial C18-SPE column. The results of the study indicated that the prepared BPA-imprinted silica nanoparticles exhibited high adsorption capacity and selectivity, and offered a fast kinetics for the rebinding of BPA. The BPA-imprinted silica nanoparticles were successfully used in SPE to selectively enrich and determine BPA from shampoo, bath lotion and cosmetic cream samples.

  15. Molecularly imprinted layer-coated silica nanoparticles for selective solid-phase extraction of bisphenol A from chemical cleansing and cosmetics samples

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Rong; Zhao Wenhui; Zhai Meijuan; Wei Fangdi; Cai Zheng; Sheng Na [School of Pharmacy, Nanjing Medical University, Hanzhong Road 140, Nanjing, Jiangsu 210029 (China); Hu Qin, E-mail: huqin@njmu.edu.cn [School of Pharmacy, Nanjing Medical University, Hanzhong Road 140, Nanjing, Jiangsu 210029 (China)

    2010-01-25

    Highly selective molecularly imprinted layer-coated silica nanoparticles for bisphenol A (BPA) were synthesized by molecular imprinting technique with a sol-gel process on the supporter of silica nanoparticles. The BPA-imprinted silica nanoparticles were characterized by fourier transform infrared spectrometer, transmission electron microscope, dynamic adsorption and static adsorption tests. The equilibrium association constant, K{sub a}, and the apparent maximum number of binding sites, Q{sub max}, were estimated to be 1.25 x 10{sup 5} mL {mu}mol{sup -1} and 16.4 {mu}mol g{sup -1}, respectively. The BPA-imprinted silica nanoparticles solid-phase extraction (SPE) column had higher selectivity for BPA than the commercial C18-SPE column. The results of the study indicated that the prepared BPA-imprinted silica nanoparticles exhibited high adsorption capacity and selectivity, and offered a fast kinetics for the rebinding of BPA. The BPA-imprinted silica nanoparticles were successfully used in SPE to selectively enrich and determine BPA from shampoo, bath lotion and cosmetic cream samples.

  16. Antithrombogenic Polymer Coating.

    Science.gov (United States)

    Huang, Zhi Heng; McDonald, William F.; Wright, Stacy C.; Taylor, Andrew C.

    2003-01-21

    An article having a non-thrombogenic surface and a process for making the article are disclosed. The article is formed by (i) coating a polymeric substrate with a crosslinked chemical combination of a polymer having at least two amino substituted side chains, a crosslinking agent containing at least two crosslinking functional groups which react with amino groups on the polymer, and a linking agent containing a first functional group which reacts with a third functional group of the crosslinking agent, and (ii) contacting the coating on the substrate with an antithrombogenic agent which covalently bonds to a second functional group of the linking agent. In one example embodiment, the polymer is a polyamide having amino substituted alkyl chains on one side of the polyamide backbone, the crosslinking agent is a phosphine having the general formula (A).sub.3 P wherein A is hydroxyalkyl, the linking agent is a polyhydrazide and the antithrombogenic agent is heparin.

  17. Qualification of anticorrosive coatings in nuclear vessels

    International Nuclear Information System (INIS)

    Test qualifications of the behavior of anticorrosive coating systems used in nuclear vessels in service and under the accident conditions of radiation decontamination, steam chemical resistance, thermal conductivity, weathering accelerated aging are presented and discussed. (author)

  18. Coating Carbon Fibers With Platinum

    Science.gov (United States)

    Effinger, Michael R.; Duncan, Peter; Coupland, Duncan; Rigali, Mark J.

    2007-01-01

    A process for coating carbon fibers with platinum has been developed. The process may also be adaptable to coating carbon fibers with other noble and refractory metals, including rhenium and iridium. The coated carbon fibers would be used as ingredients of matrix/fiber composite materials that would resist oxidation at high temperatures. The metal coats would contribute to oxidation resistance by keeping atmospheric oxygen away from fibers when cracks form in the matrices. Other processes that have been used to coat carbon fibers with metals have significant disadvantages: Metal-vapor deposition processes yield coats that are nonuniform along both the lengths and the circumferences of the fibers. The electrical resistivities of carbon fibers are too high to be compatible with electrolytic processes. Metal/organic vapor deposition entails the use of expensive starting materials, it may be necessary to use a furnace, and the starting materials and/or materials generated in the process may be hazardous. The present process does not have these disadvantages. It yields uniform, nonporous coats and is relatively inexpensive. The process can be summarized as one of pretreatment followed by electroless deposition. The process consists of the following steps: The surfaces of the fiber are activated by deposition of palladium crystallites from a solution. The surface-activated fibers are immersed in a solution that contains platinum. A reducing agent is used to supply electrons to effect a chemical reduction in situ. The chemical reduction displaces the platinum from the solution. The displaced platinum becomes deposited on the fibers. Each platinum atom that has been deposited acts as a catalytic site for the deposition of another platinum atom. Hence, the deposition process can also be characterized as autocatalytic. The thickness of the deposited metal can be tailored via the duration of immersion and the chemical activity of the solution.

  19. Dry Sintered Metal Coating of Halloysite Nanotubes

    Directory of Open Access Journals (Sweden)

    James C. Nicholson

    2016-09-01

    Full Text Available Halloysite nanotubes (HNTs are a naturally-occurring aluminosilicate whose dimensions measure microns in length and tens of nanometers in diameter. Bonding defects between the alumina and silica lead to net negative and positive charges on the exterior and interior lumen, respectively. HNTs have been shown to enhance the material properties of polymer matrices and enable the sustained release of loaded chemicals, drugs, and growth factors. Due to the net charges, these nanotubes can also be readily coated in layered-depositions using the HNT exterior lumen’s net negative charge as the basis for assembly. These coatings are primarily done through wet chemical processes, the majority of which are limited in their use of desired chemicals, due to the polarity of the halloysite. Furthermore, this restriction in the type of chemicals used often requires the use of more toxic chemicals in place of greener options, and typically necessitates the use of a significantly longer chemical process to achieve the desired coating. In this study, we show that HNTs can be coated with metal acetylacetonates—compounds primarily employed in the synthesis of nanoparticles, as metal catalysts, and as NMR shift reagents—through a dry sintering process. This method was capable of thermally decaying the metal acetylacetonate, resulting in a free positively-charged metal ion that readily bonded to the negatively-charged HNT exterior, resulting in metallic coatings forming on the HNT surface. Our coating method may enable greater deposition of coated material onto these nanotubes as required for a desired application. Furthermore, the use of chemical processes using toxic chemicals is not required, thus eliminating exposure to toxic chemicals and costs associated with the disposal of the resultant chemical waste.

  20. A Multifunctional Coating for Autonomous Corrosion Control

    Science.gov (United States)

    Calle, Luz M.; Li, Wenyan; Buhrow, Jerry W.; Jolley, Scott t.

    2011-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it. The multi-functionality of the coating is based on microencapsulation technology specifically designed for corrosion control applications. This design has, in addition to all the advantages of existing microcapsulation designs, the corrosion controlled release function that triggers the delivery of corrosion indicators and inhibitors on demand, only when and where needed. Microencapsulation of self-healing agents for autonomous repair of mechanical damage to the coating is also being pursued. Corrosion indicators, corrosion inhibitors, as well as self-healing agents, have been encapsulated and dispersed into several paint systems to test the corrosion detection, inhibition, and self-healing properties of the coating. Key words: Corrosion, coating, autonomous corrosion control, corrosion indication, corrosion inhibition, self-healing coating, smart coating, multifunctional coating, microencapsulation.

  1. Coatings on Atacama Desert Basalt: A Possible Analog for Coatings on Gusev Plains Basalt

    Science.gov (United States)

    Sutter, B.; Golden, D. C.; Amundson, R.; Chong-Diaz, G.; Ming, D. W.

    2007-01-01

    Surface coatings on Gusev Plains basalt have been observed and may contain hematite and nanophase Fe-oxides along with enrichments in P, S, Cl, and K relative to the underlying rock. The Gusev coatings may be derived from the dissolution of adhering soil and/or parent rock along with the addition of S and Cl from outside sources. Transient water for dissolution could be sourced from melting snow during periods of high obliquity, acid fog, and/or ground water (Haskin et al., 2005). Coatings on basalt in the hyper-arid (less than 2mm y(sup -1)) Atacama Desert may assist in understanding the chemistry, mineralogy and formation mechanisms of the Gusev basalt coatings. The Atacama Desert climate is proposed to be analogous to a paleo-Mars climate that was characterized by limited aqueous activity when the Gusev coatings could have formed. The objectives of this work are to (i) determine the chemical nature and extent of surface coatings on Atacama Desert basalt, and (ii) assess coating formation mechanisms in the Atacama Desert. Preliminary backscattered electron imaging of Atacama basalt thin-sections indicated that the coatings are as thick as 20 m. The boundary between the coating and the basalt labradorite, ilmenite, and augite grains was abrupt indicating that the basalt minerals underwent no chemical dissolution. The Atacama coatings have been added to the basalt instead of being derived from basalt chemical weathering. Semi-quantitative energy dispersive spectroscopy shows the coatings to be chemically homogeneous. The coating is depleted in Ca (0.9 wt% CaO) and enriched in K (1.3 wt.% K2O) and Si (69.1 wt.% SiO2) relative to the augite and labradorite grains. A dust source enriched in Si (e.g., poorly crystalline silica) and K and depleted in Ca appears to have been added to the basalt surface. Unlike the Gusev coatings, no P, S, and Cl enrichment was observed. However, Fe (3.2 wt.% FeO) was present in the Atacama coatings suggesting the present of Fe

  2. 煤化工用调节阀耐磨涂层工艺技术研究%Technology research on wear-resistant coating of control valve in coal-chemical industry

    Institute of Scientific and Technical Information of China (English)

    刘海波; 吴巧梅; 傅卫平; 马玉山; 高强

    2012-01-01

    针对煤化工用调节阀的特殊工况,为了提高阀内件表面的耐磨性,采用超音速火焰喷涂(high velocity oxy-fuel,HVOF)、等离子喷涂(atmospheric plasma spray,APS)及熔敷、等离子堆焊(plasma transferred arc,PTA)3种典型的处理工艺,并结合上述工艺选取与之相匹配典型的喷涂材料.通过磨损试验、硬度测试和显微组织结构的研究发现:APS喷涂的温度较高,引起碳化物分解并溶解于基体内,经过熔敷,涂层韧性增加,磨损表面不易产生裂纹和剥落;HVOF喷涂过程中,粒子的撞击速度高,不会产生过热现象,涂层受压应力、密度高,耐磨性好;PTA堆焊的涂层和基体的结合力较强,硬度高,涂层厚度大,耐磨性介于APS和HVOF之间.%Aiming at the special conditions of the valves used in coal chemical industry, in order to improve the wear resistance of the valve trim, three typical processing technologies are adopted, which are high velocity oxy-fuel (HVOF) ,atmospheric plasma spray (APS) and plasma transferred arc(PTA) ; and the typical materials that match the above processing technologies are selected to spray the sample. Abrasion test, hardness test and micro-structure analysis reveal that APS uses much higher spraying temperature than HVOF,which could contribute to the carbide oxidation and dissolution in the matrix,after deposition the coating flexibility increases and the worn surface is difficult to be cracked down and peeled off. In HVOF spraying process, the particles have high impact speed and overheating does not happen; and the coatings are under compressive stress, have high density and good wear resistance characteristic. The coating of PTA hardfacing has strong binding force with the base material,high hardness and good thickness, its wear resistance characteristic is between those of APS and HVOF.

  3. Peliculização e tratamento químico de sementes de algodoeiro (Gossypium hirsutum L. Film-coating and chemical treatment of cotton seeds (Gossypium hirsutum L.

    Directory of Open Access Journals (Sweden)

    Liana Baptista de Lima

    2006-12-01

    Full Text Available O estabelecimento ideal de plantas no campo é determinado, dentre outros fatores, pela qualidade fisiológica e sanitária das sementes utilizadas. Neste sentido, o tratamento químico de sementes torna-se essencial, pois proporciona melhor desempenho das mesmas no campo. Atualmente, em associação com o tratamento químico, a fim de aumentar a aderência dos produtos químicos nas sementes, dentre outros objetivos, tem sido estudada a utilização de películas de revestimento. Com este trabalho, objetivou-se avaliar a qualidade fisiológica e sanitária de sementes de algodoeiro de quatro lotes, tratadas quimicamente e peliculizadas com 2 tipos de películas comerciais. Utilizou-se dois lotes da cultivar Delta Opal, dois da cultivar Sure Grow, e dois tipos de películas, denominadas AG201 e TGBP1080. As sementes foram submetidas ao tratamento com a mistura dos fungicidas carboxin+thiram com o inseticida imidacloprid, na dosagem 5 mL/Kg + 5 mL/Kg de sementes e na dosagem 2,5 mL/Kg + 2,5 mL/Kg de sementes. Os tratamentos foram avaliados por teste de germinação, teste de emergência de plântulas, índice de velocidade de emergência, teste de frio e de sanidade. O tratamento químico com a mistura de carboxin+thiram com imidacloprid, na dosagem 5 mL/Kg + 5 mL/Kg de sementes promove melhor desempenho das sementes, sendo eficaz no controle de fungos. O uso da peliculização não possibilita redução da dosagem do tratamento químico. A peliculização não afeta a germinação, emergência e índice de velocidade de emergência de lotes de alta qualidade.Physiological and healthy quality of cotton seeds (Gossypium hirsutum L. are decisive factor to establish an ideal stand in the field. The chemical seed treatment is necessary to preserve the healthy quality and to obtain a better development performance of the seeds in the field. Actually, researches on chemical treatment are liberally conducted, which film-coating technique has been used

  4. Evaluation of hot corrosion behavior of thermal barrier coatings

    Science.gov (United States)

    Hodge, P. E.; Miller, R. A.; Gedwill, M. A.

    1980-01-01

    Calcium silicate and yttria stabilized zirconia/MCrAlY thermal barrier coating systems on air-cooled specimens were exposed to sodium plus vanadium doped Mach 0.3 combustion gases. Thermal barrier coating endurance was determined to be a strong inverse function of ceramic coating thickness. Coating system durability was increased through the use of higher Cr + Al NiCrAl and CoCrAlY bond coatings. Chemical and electron microprobe analyses supported the predictions of condensate compositions and the determination of their roles in causing spalling of the ceramic coatings.

  5. Mineralogical, Chemical, and Isotopic Characterization of Fracture-Coating Minerals in Borehole Samples from Western Pahute Mesa and Oasis Valley, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Benedict, F C; Rose, T P; Zhou, X

    2000-09-01

    This report summarizes the results of a mineralogical and geochemical investigation of fracture-coating phases obtained from archived borehole core and cuttings samples from the western Pahute Mesa-Oasis Valley region. The objective is to provide data needed to validate UGTA flow and transport models for this region. Fracture-lining minerals were characterized using micrographic techniques (SEM-EDS), and selected calcite samples were analyzed for their stable isotope ({sup 13}C/{sup 12}C and {sup 18}O/{sup 16}O) and rare earth element (REE) abundances. The main conclusions are as follows: (1) The distribution of fracture-lining mineral phases is a function of primary rock type, the style and degree of syn-depositional alteration, effects of post-depositional hydrothermal alteration, and fracture location relative to recharge waters (in the unsaturated zone) or through going groundwater (in the saturated zone). (2) Fracture-lining minerals within the welded tuff aquifers (principally the Timber Mountain and Paintbrush Tuffs) are characterized by the assemblage calcite + chalcedony + Fe- and Mn-oxyhydroxides + mixed illite/smectite (in approximate decreasing order of abundance). The predominant mode of host rock alteration is quartzofeldspathic. (3) Interbedded rhyolitic lava flow aquifers are characterized by the fracture-lining assemblage chalcedony + mixed illite/smectite + Fe- and Mn-oxyhydroxides {+-} calcite {+-} quartz {+-} K-feldspar (in approximate decreasing order of abundance). These include lava flow aquifers from the Thirsty Canyon, Beatty Wash, Paintbrush, and Quartz Mountain groups. The predominant mode of host rock alteration is quartzofeldspathic. (4) Fracture-lining zeolite minerals are abundant only within one of the basaltic lava flow aquifers (Trachyte of Ribbon Cliff) where they occur with chalcedony + calcite + clay minerals. (5) Stable isotope analyses ({sup 13}C/{sup 12}C and {sup 18}O/{sup 16}O) of secondary calcite samples were used to

  6. The Different Sensitive Behaviors of a Hydrogen-Bond Acidic Polymer-Coated SAW Sensor for Chemical Warfare Agents and Their Simulants

    Directory of Open Access Journals (Sweden)

    Yin Long

    2015-07-01

    Full Text Available A linear hydrogen-bond acidic (HBA linear functionalized polymer (PLF, was deposited onto a bare surface acoustic wave (SAW device to fabricate a chemical sensor. Real-time responses of the sensor to a series of compounds including sarin (GB, dimethyl methylphosphonate (DMMP, mustard gas (HD, chloroethyl ethyl sulphide (2-CEES, 1,5-dichloropentane (DCP and some organic solvents were studied. The results show that the sensor is highly sensitive to GB and DMMP, and has low sensitivity to HD and DCP, as expected. However, the sensor possesses an unexpected high sensitivity toward 2-CEES. This good sensing performance can’t be solely or mainly attributed to the dipole-dipole interaction since the sensor is not sensitive to some high polarity solvents. We believe the lone pair electrons around the sulphur atom of 2-CEES provide an electron-rich site, which facilitates the formation of hydrogen bonding between PLF and 2-CEES. On the contrary, the electron cloud on the sulphur atom of the HD molecule is offset or depleted by its two neighbouring strong electron-withdrawing groups, hence, hydrogen bonding can hardly be formed.

  7. Environmentally regulated aerospace coatings

    Science.gov (United States)

    Morris, Virginia L.

    1995-01-01

    Aerospace coatings represent a complex technology which must meet stringent performance requirements in the protection of aerospace vehicles. Topcoats and primers are used, primarily, to protect the structural elements of the air vehicle from exposure to and subsequent degradation by environmental elements. There are also many coatings which perform special functions, i.e., chafing resistance, rain erosion resistance, radiation and electric effects, fuel tank coatings, maskants, wire and fastener coatings. The scheduled promulgation of federal environmental regulations for aerospace manufacture and rework materials and processes will regulate the emissions of photochemically reactive precursors to smog and air toxics. Aerospace organizations will be required to identify, qualify and implement less polluting materials. The elimination of ozone depleting chemicals (ODC's) and implementation of pollution prevention requirements are added constraints which must be addressed concurrently. The broad categories of operations affected are the manufacture, operation, maintenance, and repair of military, commercial, general aviation, and space vehicles. The federal aerospace regulations were developed around the precept that technology had to be available to support the reduction of organic and air toxic emissions, i.e., the regulations cannot be technology forcing. In many cases, the regulations which are currently in effect in the South Coast Air Quality Management District (SCAQMD), located in Southern California, were used as the baseline for the federal regulations. This paper addresses strategies used by Southern California aerospace organizations to cope with these regulatory impacts on aerospace productions programs. All of these regulatory changes are scheduled for implementation in 1993 and 1994, with varying compliance dates established.

  8. Nanocarbon-Coated Porous Anodic Alumina for Bionic Devices

    OpenAIRE

    Morteza Aramesh; Wei Tong; Kate Fox; Ann Turnley; Dong Han Seo; Steven Prawer; Kostya (Ken) Ostrikov

    2015-01-01

    A highly-stable and biocompatible nanoporous electrode is demonstrated herein. The electrode is based on a porous anodic alumina which is conformally coated with an ultra-thin layer of diamond-like carbon. The nanocarbon coating plays an essential role for the chemical stability and biocompatibility of the electrodes; thus, the coated electrodes are ideally suited for biomedical applications. The corrosion resistance of the proposed electrodes was tested under extreme chemical conditions, su...

  9. Tribological properties of CrNx coatings

    Directory of Open Access Journals (Sweden)

    B. Warcholinski

    2009-12-01

    Full Text Available Purpose: The purpose of this work is the characterization of the tribological properties thin Cr-N coatings, both monolayer Cr2N, CrN coatings and multilayer Cr/CrN, Cr2N/CrN coatings, deposited by cathodic arc physical vapour deposition (CAPVD.Design/methodology/approach: The deposition parameters of Cr2N and CrN were determined. Structure of the coatings were investigated using the scanning electron microscopy (SEM. The XRD examination was carried out to specify the phase structure, EDS to define the chemical composition of the coatings. The investigation includes also microhardness, roughness tests, adhesion, friction coefficient and wear rate.Findings: Basing on the scratch test it was shown that the influence of the architecture on the coating’ adhesion is dominant. It was found that the all tested coatings show high critical load Lc2 >70 N. The multilayer coatings show higher critical load when compared to monolayer coatings.Research limitations/implications: The main limitation of this work is linked to the deposition technique itself.It is difficult to avoid surface defects and pinholes that strongly influence the tribological results.Practical implications: Chromium based coatings present good mechanical properties which allow them to be used in several applications; from decorative to protective coatings.Originality/value: The comparison of adhesion and wear resistance of mono- and multilayer coatings based on chromium. The deposition technology enable to obtain the coatings with high adhesion to the substrate. This may be important to advanced coatings industry.

  10. Corrosion resistant coating

    Science.gov (United States)

    Wrobleski, Debra A.; Benicewicz, Brian C.; Thompson, Karen G.; Bryan, Coleman J.

    1997-01-01

    A method of protecting a metal substrate from corrosion including coating a metal substrate of, e.g., steel, iron or aluminum, with a conductive polymer layer of, e.g., polyaniline, coating upon said metal substrate, and coating the conductive polymer-coated metal substrate with a layer of a topcoat upon the conductive polymer coating layer, is provided, together with the resultant coated article from said method.

  11. Purely inorganic coatings based on nanoparticles for magnesium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Feil, Florian [DECHEMA e.V., Karl-Winnacker-Institut, Frankfurt am Main (Germany)], E-mail: feil@dechema.de; Fuerbeth, Wolfram; Schuetze, Michael [DECHEMA e.V., Karl-Winnacker-Institut, Frankfurt am Main (Germany)

    2009-03-30

    The chemical nanotechnology is offering a chance to apply stable inorganic coatings onto magnesium alloys. The cast alloy AZ91 as well as the wrought alloy AZ31 could be dip-coated with aqueous dispersions based on commercially available silica particles and various additives. The high surface activity of the nanoparticles and appropriate additives, e.g. boron, aluminium or alkali salts, help to densify these coatings under moderate conditions even suitable for those thermally precarious magnesium alloys. Another coating technique is based on the electrophoretic deposition of nanoparticles already containing all sintering aids. These particles could be synthesised by a base-catalysed sol-gel process. Polydiethoxysiloxane can act as an adhesion promoter for these coatings. Additionally concentration gradients of different oxides within these particles can adjust the coating properties, too. Usually single coatings are very thin (200-500 nm). However, multiple coating applications as well as a process involving special particle mixtures lead to coatings with a thickness of up to several micrometers. Even after thermal treatment at 200 or 400 deg. C these coatings stay crack-free. The composition and texture of these coatings were studied using IR, atomic force microscopy (AFM), scanning electron microscopy (SEM) and other techniques. Electrochemical impedance measurements show an improvement of the corrosion performance by these coatings. The coating resistance is improving with the coating thickness.

  12. HIGH TEMPERATURE OXIDATION PERFORMANCE OF ALUMINIDE COATINGS

    Energy Technology Data Exchange (ETDEWEB)

    Pint, B.A.; Zhang, Y.; Haynes, J.A.; Wright, I.G.

    2003-04-22

    In order to determine the potential benefits and limitations of aluminide coatings, coatings made by chemical vapor deposition (CVD) on Fe- and Ni-base alloy substrates are being evaluated in various high-temperature environments. Testing of coatings on representative ferritic (Fe-9Cr-1Mo) and austenitic (type 304L stainless steel) alloys has found that high frequency thermal cycling (1h cycle time) can significantly degrade the coating. Based on comparison with similar specimens with no thermal cycling or a longer cycle time (100h), this degradation was not due to Al loss from the coating but most likely because of the thermal expansion mismatch between the coating and the substrate. Several coated Ni-base alloys were tested in a high pressure (20atm) steam-CO2 environment for the ZEST (zero-emission steam turbine) program. Coated specimens showed less mass loss than the uncoated specimens after 1000h at 900 C and preliminary characterization examined the post-test coating structure and extent of attack.

  13. Scalable graphene coatings for enhanced condensation heat transfer.

    Science.gov (United States)

    Preston, Daniel J; Mafra, Daniela L; Miljkovic, Nenad; Kong, Jing; Wang, Evelyn N

    2015-05-13

    Water vapor condensation is commonly observed in nature and routinely used as an effective means of transferring heat with dropwise condensation on nonwetting surfaces exhibiting heat transfer improvement compared to filmwise condensation on wetting surfaces. However, state-of-the-art techniques to promote dropwise condensation rely on functional hydrophobic coatings that either have challenges with chemical stability or are so thick that any potential heat transfer improvement is negated due to the added thermal resistance of the coating. In this work, we show the effectiveness of ultrathin scalable chemical vapor deposited (CVD) graphene coatings to promote dropwise condensation while offering robust chemical stability and maintaining low thermal resistance. Heat transfer enhancements of 4× were demonstrated compared to filmwise condensation, and the robustness of these CVD coatings was superior to typical hydrophobic monolayer coatings. Our results indicate that graphene is a promising surface coating to promote dropwise condensation of water in industrial conditions with the potential for scalable application via CVD.

  14. Oxidation resistance and mechanical properties of HfC nanowire-toughened ultra-high temperature ceramic coating for SiC-coated C/C composites

    Science.gov (United States)

    Ren, Jincui; Zhang, Yulei; Hu, Heng; Fei, Tian; Li, Hejun

    2016-01-01

    To improve the oxidation resistance of carbon/carbon (C/C) composites, a dense HfC nanowire-toughened ultra-high temperature ceramic multiphase coating was prepared on SiC-coated C/C composites by chemical vapor deposition (CVD) and pack cementation. The microstructure, mechanical and oxidation resistance properties of the coating were investigated. The results show that the HfC nanowires in the coating could suppress the cracking of the coating and then improve the toughness of the coating. The flexural property, thermal shock and isothermal oxidation resistance of the coating were all improved due to the incorporation of HfC nanowires.

  15. The implementation and application of chemical cleaning and anti-corrosive coating of the condenser%凝汽器化学清洗及防腐镀膜的实施及应用

    Institute of Scientific and Technical Information of China (English)

    田红艳

    2011-01-01

    影响发电机组安全运行的因素有很多,凝汽器铜管的腐蚀就是其中之一。凝汽器铜管一旦发生腐蚀泄漏,冷却水便会漏入凝结水中,从而导致锅炉、汽轮机等设备的腐蚀与结垢。对凝汽器铜管进行化学清洗及防腐镀膜,可以有效阻止或缓解各类腐蚀,延长凝汽器使用寿命,减少因铜管泄漏造成的紧急停机、凝结水浪费、锅炉结垢,避免设备提前更换、甚至安全事故等风险。大大延长铜管的使用寿命,有利于凝汽器安全经济运行。%There are many factors in influencing the safe operation of the generator, and corrosion of the condenser copper pipe is one of them. Once the corrosion and leakage of the condenser copper pipe happened, it will lead to cooling water leak into the condensed water, and the corrosion and fouling of boiler and turbine was thereby produced. If the condenser copper pipe were dealt with the chemical cleaning and anti-corrosive coating, some risks will be reduced. Then kinds of corrosion can be effectively prevented or alleviated, service life of the condenser can be prolonged, emergency stop, condensed water waste and boiler scale caused by copper tube leakage will be reduced, replacement of the equipments in early, even accidents will avoid. Greatly extend the service life of the copper pipe will benefit to the safe and economical operation of the condenser.

  16. Engineered CVD Diamond Coatings for Machining and Tribological Applications

    Science.gov (United States)

    Dumpala, Ravikumar; Chandran, Maneesh; Ramachandra Rao, M. S.

    2015-07-01

    Diamond is an allotropes of carbon and is unique because of its extreme hardness (~100 GPa), low friction coefficient (Diamond is being synthesized artificially in bulk form as well as in the form of surface coatings for various engineering applications. The mechanical characteristics of chemical vapor deposited (CVD) diamond coatings such as hardness, adhesion, friction coefficient, and fracture toughness can be tuned by controlling the grain size of the coatings from a few microns to a few nanometers. In this review, characteristics and performance of the CVD diamond coatings deposited on cemented tungsten carbide (WC-Co) substrates were discussed with an emphasis on WC-Co grade selection, substrate pretreatment, nanocrystallinity and microcrystallinity of the coating, mechanical and tribological characteristics, coating architecture, and interfacial adhesion integrity. Engineered coating substrate architecture is essential for CVD diamond coatings to perform well under harsh and highly abrasive machining and tribological conditions.

  17. Electrocurtain coating process for coating solar mirrors

    Science.gov (United States)

    Kabagambe, Benjamin; Boyd, Donald W.; Buchanan, Michael J.; Kelly, Patrick; Kutilek, Luke A.; McCamy, James W.; McPheron, Douglas A.; Orosz, Gary R.; Limbacher, Raymond D.

    2013-10-15

    An electrically conductive protective coating or film is provided over the surface of a reflective coating of a solar mirror by flowing or directing a cation containing liquid and an anion containing liquid onto the conductive surface. The cation and the anion containing liquids are spaced from, and preferably out of contact with one another on the surface of the reflective coating as an electric current is moved through the anion containing liquid, the conductive surface between the liquids and the cation containing liquid to coat the conductive surface with the electrically conductive coating.

  18. CRADLE-TO-GRAVE ENVIRONMENTALLY COMPLIANT, NO-VOC FURNITURE COATING - PHASE I

    Science.gov (United States)

    The cost to worker safety, the environment and industry of applying millions of gallons of solvent-based furniture coatings per year is staggering and potentially irreversible. Removal of furniture coatings via chemical stripping also introduces toxic, volatile organic compounds ...

  19. Superhydrophobic Ceramic Coatings by Solution Precursor Plasma Spray

    Science.gov (United States)

    Cai, Yuxuan; Coyle, Thomas W.; Azimi, Gisele; Mostaghimi, Javad

    2016-04-01

    This work presents a novel coating technique to manufacture ceramic superhydrophobic coatings rapidly and economically. A rare earth oxide (REO) was selected as the coating material due to its hydrophobic nature, chemical inertness, high temperature stability, and good mechanical properties, and deposited on stainless steel substrates by solution precursor plasma spray (SPPS). The effects of various spraying conditions including standoff distance, torch power, number of torch passes, types of solvent and plasma velocity were investigated. The as-sprayed coating demonstrated a hierarchically structured surface topography, which closely resembles superhydrophobic surfaces found in nature. The water contact angle on the SPPS superhydrophobic coating was up to 65% higher than on smooth REO surfaces.

  20. Waterborne UV coating for industrial applications

    International Nuclear Information System (INIS)

    (Full Text): Solvent borne industrial coatings are being replaced by environment friendly coatings like Ultra Violet (UV) or Electron Beam (Eb) cured coatings, Powder coatings and Waterborne coatings. Waterborne systems enjoy the biggest share from this shift. UV and EB coatings provide the advantages of instant cure at room temperature, high scratch and abrasion resistance combined with excellent chemical resistance. Polyurethane (PU) chemistry is the dominant chemistry in Industrial coatings as they provide a very high level of performance. Most PU coatings are solvent based 2-component systems comprising of a resin and a cross linker. Polyurethane dispersions (PUD) in water in single pack are available but mainly addresses the Do It Yourself (DIY) market because of their slow drying speeds. Performance of PUD in most cases is inferior to solvent borne 2-component PU systems.Therefore the combination of PU dispersion and UV/EB curable technology has led to new innovative waterborne polymers called UV curable polyurethane dispersions (UVPUD). UVPUD are zero VOC systems as they are coalescent free. They are higher in molecular weight than standard UV curable products resulting in lower shrinkage coatings and provide good adhesion to substrates. Their low-viscosity makes them suitable for application by spray, curtain coater and even roller coater, without having to use monomers. UVPUD display superior chemical and mechanical properties necessary to protect high quality surface from the challenging usage conditions. UVPUD resins are therefore tailor-made to address performance needs like excellence in outdoor durability, scratch resistance, stain resistance, adhesion etc. UVPUD technology is now growing rapidly in industrial coatings for applications such as resilient flooring, wooden parquet flooring, automotive interior plastics, mobile phones etc. (Author)

  1. High vacuum tribology of polycrystalline diamond coatings

    Indian Academy of Sciences (India)

    Awadesh K Mallik; S A Shivashankar; S K Biswas

    2009-10-01

    Polycrystalline diamond coatings have been grown on unpolished side of Si(100) wafers by hot filament chemical vapour deposition process. The morphology of the grown coatings has been varied from cauliflower morphology to faceted morphology by manipulation of the growth temperature from 700°C to 900°C and methane gas concentration from 3% to 1·5%. It is found that the coefficient of friction of the coatings under high vacuum of 133·32 × 10-7 Pa (10-7 torr) with nanocrystalline grains can be manipulated to 0·35 to enhance tribological behaviour of bare Si substrates.

  2. The Durability of Epoxy Resin Coating

    Institute of Scientific and Technical Information of China (English)

    ZHAO Fujun; BA Hengjing; GAO Xiaojian

    2008-01-01

    The durability of epoxy resin coating was studied under environments with relative humidity(RH) of 98%-100%, at 55 ℃ for 900 h, at 65℃ for 700 h and at 75 ℃ for 400 h, respectively. Peel strength test, dynamical mechanical thermal analysis (DMTA), infrared spectroscopy (IR) and energy dispersive X-ray spectroscopy (EDX) were employed for measurements. Peel strength indicated the development of adhesive property of the coating, DMTA indicated the development of physical property, IR revealed the development of chemical structure, and EDX showed surface element change of the coating. All these results show a good time-temperature equivalence characteristic between humidity aging time and temperature.

  3. Applications of sol gel ceramic coatings

    International Nuclear Information System (INIS)

    The sol gel method is a chemical technique in which polycrystalline ceramic films are fabricated from a solution of organometallic precursors. The technique is attractive for many industrial applications because it is a simple (films are processed in air), flexible (can be used to coat complex geometries) and cost effective (does not require expensive equipment) process. In addition, dense, high quality coatings can be achieved at much lower temperatures than is generally required for sintering bulk ceramics. In this paper the conventional sol gel method and the new datec process are reviewed and potential applications of sol gel coatings in automotive, aerospace, petrochemical, nuclear and electronic industries are discussed. (orig.)

  4. Tribological performance of DLC coatings on UHMWPE

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Nogues, V; Medel, F J; Mariscal, M D; Endrino, J L; Krzanowski, J; Yubero, F; Puertolas, J A, E-mail: enav@unizar.es

    2010-11-01

    Diamond like carbon (DLC) coatings were deposited by several methods (ion beam assisted evaporation, magnetron sputtering, filter cathodic arc, and plasma enhanced chemical vapor deposition) onto medical grade ultra-high-molecular weight polyethylene (UHMWPE) discs. The chemical characteristics and mechanical properties of the deposited DLC coatings were studied by Raman spectroscopy and nanoindentation, respectively. In addition, a set of tribological tests was conducted at human body temperature and under bovine serum lubrication against alumina balls. After testing, wear tracks were both visually inspected and documented using confocal microscopy. Visual inspection of the wear tracks confirmed that the DLC coatings were completely removed in all cases, the only exception being the DLC coating prepared by magnetron sputtering with thickness about 0.5 microns. Although this type of DLC coating exhibited the highest friction coefficient, and therefore it suggested a somewhat lower resistance to abrasive/adhesive wear conditions, no evidence of cracking or delamination was observed after the high contact pressure wear testing. This fact points out a good substrate-coating adhesion, and confirms magnetron sputtered DLC as a potential coating for orthopaedic applications.

  5. Tribological performance of DLC coatings on UHMWPE

    International Nuclear Information System (INIS)

    Diamond like carbon (DLC) coatings were deposited by several methods (ion beam assisted evaporation, magnetron sputtering, filter cathodic arc, and plasma enhanced chemical vapor deposition) onto medical grade ultra-high-molecular weight polyethylene (UHMWPE) discs. The chemical characteristics and mechanical properties of the deposited DLC coatings were studied by Raman spectroscopy and nanoindentation, respectively. In addition, a set of tribological tests was conducted at human body temperature and under bovine serum lubrication against alumina balls. After testing, wear tracks were both visually inspected and documented using confocal microscopy. Visual inspection of the wear tracks confirmed that the DLC coatings were completely removed in all cases, the only exception being the DLC coating prepared by magnetron sputtering with thickness about 0.5 microns. Although this type of DLC coating exhibited the highest friction coefficient, and therefore it suggested a somewhat lower resistance to abrasive/adhesive wear conditions, no evidence of cracking or delamination was observed after the high contact pressure wear testing. This fact points out a good substrate-coating adhesion, and confirms magnetron sputtered DLC as a potential coating for orthopaedic applications.

  6. Multi-layer coatings

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-28

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

  7. Platinum and Iridium Coatings Obtained by Double Glow Plasma Technology

    Institute of Scientific and Technical Information of China (English)

    WU Wangping; CHEN Zhaofeng; CHEN Zhou; CONG Xiangna; QIU Jinlian

    2012-01-01

    Pt and Ir coatings were produced by double glow plasma technology on the surface of Ti alloy substrates.The chemical compositions of the coatings were determined by X-ray diffraction and X-ray photoelectron spectroscopy.The microstructure and morphology of the coatings were observed by scanning electron microscopy.The hardness and elastic modulus of the coatings were estimated by nanoindentation.The measurements of adhesive forces of the coatings were performed with scratch tester.The results indicated that the Pt and Ir coatings displayed the preferred (220) orientation due to the initial nuclei with preferred growth on the surface of the substrates.The interface between the Pt coating and substrate exhibited no evidence of delamination.The Ir coating was composed of irregular columnar grains with many nanovoids at the interface between the coating and substrate.The mean values of hardness for Pt and Ir coatings were 0.9 GPa and 9 GPa,respectively.The elastic modulus of Pt and Ir coatings were 178 GPa and 339 GPa,respectively.The adhesive forces of the Pt and Ir coatings were about 66.4 N and 55 N,respectively.The Pt and Ir coatings adhered well to the Ti alloy substrates.

  8. Thermal coatings for titanium-aluminum alloys

    Science.gov (United States)

    Cunnington, George R.; Clark, Ronald K.; Robinson, John C.

    1993-01-01

    Titanium aluminides and titanium alloys are candidate materials for use in hot structure and heat-shield components of hypersonic vehicles because of their good strength-to-weight characteristics at elevated temperature. However, in order to utilize their maximum temperature capability, they must be coated to resist oxidation and to have a high total remittance. Also, surface catalysis for recombination of dissociated species in the aerodynamic boundary layer must be minimized. Very thin chemical vapor deposition (CVD) coatings are attractive candidates for this application because of durability and very light weight. To demonstrate this concept, coatings of boron-silicon and aluminum-boron-silicon compositions were applied to the titanium-aluminides alpha2 (Ti-14Al-21Nb), super-alpha2 (Ti-14Al-23-Nb-2V), and gamma (Ti-33Al-6Nb-1Ta) and to the titanium alloy beta-21S (Ti-15Mo-3Al-3Nb-0.2Si). Coated specimens of each alloy were subjected to a set of simulated hypersonic vehicle environmental tests to determine their properties of oxidation resistance, surface catalysis, radiative emittance, and thermal shock resistance. Surface catalysis results should be viewed as relative performance only of the several coating-alloy combinations tested under the specific environmental conditions of the LaRC Hypersonic Materials Environmental Test System (HYMETS) arc-plasma-heated hypersonic wind tunnel. Tests were also conducted to evaluate the hydrogen transport properties of the coatings and any effects of the coating processing itself on fatigue life of the base alloys. Results are presented for three types of coatings, which are as follows: (1) a single layer boron silicon coating, (2) a single layer aluminum-boron-silicon coating, and (3) a multilayer coating consisting of an aluminum-boron-silicon sublayer with a boron-silicon outer layer.

  9. Investigation of metallurgical coatings for automotive applications

    Science.gov (United States)

    Su, Jun Feng

    Metallurgical coatings have been widely used in the automotive industry from component machining, engine daily running to body decoration due to their high hardness, wear resistance, corrosion resistance and low friction coefficient. With high demands in energy saving, weight reduction and limiting environmental impact, the use of new materials such as light Aluminum/magnesium alloys with high strength-weight ratio for engine block and advanced high-strength steel (AHSS) with better performance in crash energy management for die stamping, are increasing. However, challenges are emerging when these new materials are applied such as the wear of the relative soft light alloys and machining tools for hard AHSS. The protective metallurgical coatings are the best option to profit from these new materials' advantages without altering largely in mass production equipments, machinery, tools and human labor. In this dissertation, a plasma electrolytic oxidation (PEO) coating processing on aluminum alloys was introduced in engine cylinder bores to resist wear and corrosion. The tribological behavior of the PEO coatings under boundary and starve lubrication conditions was studied experimentally and numerically for the first time. Experimental results of the PEO coating demonstrated prominent wear resistance and low friction, taking into account the extreme working conditions. The numerical elastohydrodynamic lubrication (EHL) and asperity contact based tribological study also showed a promising approach on designing low friction and high wear resistant PEO coatings. Other than the fabrication of the new coatings, a novel coating evaluation methodology, namely, inclined impact sliding tester was presented in the second part of this dissertation. This methodology has been developed and applied in testing and analyzing physical vapor deposition (PVD)/ chemical vapor deposition (CVD)/PEO coatings. Failure mechanisms of these common metallurgical hard coatings were systematically

  10. Electrochemical and chemical dissolution behavior of Zn-Fe alloy coatings and its application to the analysis of Zn-Fe alloy layer. Zn-Fe kei mekki so no bunkyokuter dot yokai kyodo to teiryo bunseki eno oyo

    Energy Technology Data Exchange (ETDEWEB)

    Tanimoto, S.; Funahashi, Y.; Matsumura, Y. (Kawasaki Steel Corp., Tokyo (Japan))

    1991-11-01

    As surface treated steel sheets, steel sheets with Zn-Fe coatings as well as double-layer steel sheets with Fe-P alloy coatings on Zn-Fe alloy coatings are often used practically. Two treatment methods, which are used to dissolve only alloy layers without dissolving steel sheets in order to find amount and composition of alloy layersr have already been reported. This report investigates the mechanisms of these methods, particularly the mechanisms to control dissolution of steel sheets. In the alkali-dissolution method, Zn-Fe alloy coatings are dissolved in a strong alkaline solution(NaOH-triethanolamine (TEA)-H{sub 2}O{sub 2}). In this case, steel sheets are insoluble because passive films are formed on the surface. In the cathodic polarization electrolysis method, alloy layers are electrolyzed({minus}l.2V) and dissolved in an ammonium nitrate-0-phen electrolyte. At this potential, dissolution of steel sheets can be prevented by the 0-phen films adsorbed on the surface. Consequently, the alkali-dissolution mehtod and the cathodic polarization electrolysis method are applicable to the quantitative analysis of Zn-rich layer (Fe is 40% or less) coatings and that of Fe-rich layer(Fe is 70% or less) coatings, respectively. 18 refs., 8 figs., 7 tabs.

  11. Flow coating apparatus and method of coating

    Science.gov (United States)

    Hanumanthu, Ramasubrahmaniam; Neyman, Patrick; MacDonald, Niles; Brophy, Brenor; Kopczynski, Kevin; Nair, Wood

    2014-03-11

    Disclosed is a flow coating apparatus, comprising a slot that can dispense a coating material in an approximately uniform manner along a distribution blade that increases uniformity by means of surface tension and transfers the uniform flow of coating material onto an inclined substrate such as for example glass, solar panels, windows or part of an electronic display. Also disclosed is a method of flow coating a substrate using the apparatus such that the substrate is positioned correctly relative to the distribution blade, a pre-wetting step is completed where both the blade and substrate are completed wetted with a pre-wet solution prior to dispensing of the coating material onto the distribution blade from the slot and hence onto the substrate. Thereafter the substrate is removed from the distribution blade and allowed to dry, thereby forming a coating.

  12. Process engineering of ceramic composite coatings for fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Li, G.; Kim, H.; Chen, M.; Yang, Q.; Troczynski, T. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Metals and Materials Engineering

    2003-07-01

    Researchers at UBCeram at the Department of Metals and Materials Engineering at the University of British Columbia have developed a technology to chemically bond composite sol-gel (CB-CSG) coating onto metallic surfaces of complex or concave shapes. The process has been optimized for electrically resistive coatings and corrosion-resistant coatings. The CSG is sprayed onto metallic surfaces and is heat-treated at 300 degrees C to partially dehydrate the hydroxides. The CSG film is then chemically bonded through reaction of active alumina with metal phosphates, such as aluminium phosphate. A new chromate-free process is being developed to address the issue of coatings porosity. The electrodeposition technique involves polymer particles mixed with suspended fine alumina particles which are co-deposited by electrophoretic means or by electrocoagulation. The composite e-coatings have excellent mechanical properties and are being considered as a protective coating for various components of fuel cell systems. 9 refs., 7 figs.

  13. Automatic and robust deposition process control to grow hard ncTiC/a-C:H coatings using industrial magnetron sputtering devices and tribological analysis of the titanium-carbon coatings

    NARCIS (Netherlands)

    Žemlička, Radek; Jílek, Mojmír; Vogl, Petr; Pei, Yutao; Souček, Pavel; Buršíková, Vilma; Vašina, Petr

    2015-01-01

    nc-TiC/a-C:H coatings consist of TiC crystallites embedded in an amorphous hydrogenated carbon matrix. Depending mainly on the chemical composition, the properties of these coatings can be tailored from hard coatings, with hardness of greater than 35 GPa to tribological coatings, with coefficients o

  14. Coating of pumps; coating af pumper

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Hans; Moritzen, J.; Thoegersen, Jeanette

    2005-11-15

    Coating of pumps is a quite new activity. For many years pipes and containers have been coated inside in order to avoid corrosion, but the technology has only been used inside pumps for the last ten years. The technology comes from USA and is originally developed in the space technology industry as an exceptionally durable and corrosion constant coating. The project is a further development of results found in a previous R and D project in which measurements were performed before and after coating two different installations. Both installations showed large efficiency improvements. This project supplements the theory behind losses in pumps with measurements on more pumps. (BA)

  15. Mechanically reliable scales and coatings

    Energy Technology Data Exchange (ETDEWEB)

    Tortorelli, P.F.; Alexander, K.B. [Oak Ridge National Lab., TN (United States)

    1995-06-01

    In many high-temperature fossil energy systems, corrosion and deleterious environmental effects arising from reactions with reactive gases and condensible products often compromise materials performance and, as a consequence, degrade operating efficiencies. Protection of materials from such reactions is best afforded by the formation of stable surface oxides (either as deposited coatings or thermally grown scales) that are slowly reacting, continuous, dense, and adherent to the substrate. However, the ability of normally brittle ceramic films and coatings to provide such protection has long been problematical, particularly for applications involving numerous or severe high-temperature thermal cycles or very aggressive (for example, sulfidizing) environments. A satisfactory understanding of how scale and coating integrity and adherence are improved by compositional, microstructural, and processing modifications is lacking. Therefore, to address this issue, the present work is intended to define the relationships between substrate characteristics (composition, microstructure, and mechanical behavior) and the structure and protective properties of deposited oxide coatings and/or thermally grown scales. Such information is crucial to the optimization of the chemical, interfacial, and mechanical properties of the protective oxides on high-temperature materials through control of processing and composition and directly supports the development of corrosion-resistant, high-temperature materials for improved energy and environmental control systems.

  16. Superior Thermal Barrier Coatings Using Solution Precursor Plasma Spray

    Science.gov (United States)

    Jordan, E. H.; Xie, L.; Gell, M.; Padture, N. P.; Cetegen, B.; Ozturk, A.; Ma, X.; Roth, J.; Xiao, T. D.; Bryant, P. E. C.

    2004-03-01

    A novel process, solution precursor plasma spray (SPPS), is presented for depositing thermal barrier coatings (TBCs), in which aqueous chemical precursors are injected into a standard direct current plasma spray system. The resulting coatings microstructure has three unique features: (1) ultra fine splats (1 µm), (2) nanometer and micron-sized interconnected porosity, and (3) closely spaced, through-thickness cracks. Coatings over 3 mm thick can be readily deposited using the SPPS process. Coating durability is excellent, with SPPS coatings showing, in furnace cycling tests, 2.5 times the spallation life of air plasma coatings (APS) and 1.5 times the life of electron beam physical vapor deposited (EB-PVD) coatings. The conductivity of SPPS coatings is lower than EB-PVD coatings and higher than the best APS coatings. Manufacturing cost is expected to be similar to APS coatings and much lower than EB-PVD coatings. The SPPS deposition process includes droplet break-up and material arriving at the deposition surface in various physical states ranging from aqueous solution, gel phase, to fully-molten ceramic. The relation between the arrival state of the material and the microstructure is described.

  17. Microstructure and corrosion resistance of phytic acid conversion coatings for magnesium alloy

    International Nuclear Information System (INIS)

    In this paper, a new innoxious and pollution-free chemical protective coating for magnesium alloys, phytic acid conversion coating, was prepared. The conversion coatings are found to have high cover ratio and no cracks are found by atomic force microscopes (AFM) and scanning electron microscopy (SEM). The main elements of the conversion coatings are Mg, Al, O, P and C by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The chemical state of the elements in the coatings was also investigated by Fourier transform infrared spectroscopy (FTIR). AES depth profile analysis suggests that the thickness of the conversion coating is about 340 nm. The corrosion resistance of the coatings was evaluated by polarization curves. The results indicate that the corrosion resistance for the conversion coated AZ91D magnesium alloys in 3.5% NaCl solution increases markedly. The mechanisms of corrosion resistance and coatings formation are also discussed.

  18. Microstructure and corrosion resistance of phytic acid conversion coatings for magnesium alloy

    Science.gov (United States)

    Cui, Xiufang; Li, Qingfen; Li, Ying; Wang, Fuhui; Jin, Guo; Ding, Minghui

    2008-12-01

    In this paper, a new innoxious and pollution-free chemical protective coating for magnesium alloys, phytic acid conversion coating, was prepared. The conversion coatings are found to have high cover ratio and no cracks are found by atomic force microscopes (AFM) and scanning electron microscopy (SEM). The main elements of the conversion coatings are Mg, Al, O, P and C by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The chemical state of the elements in the coatings was also investigated by Fourier transform infrared spectroscopy (FTIR). AES depth profile analysis suggests that the thickness of the conversion coating is about 340 nm. The corrosion resistance of the coatings was evaluated by polarization curves. The results indicate that the corrosion resistance for the conversion coated AZ91D magnesium alloys in 3.5% NaCl solution increases markedly. The mechanisms of corrosion resistance and coatings formation are also discussed.

  19. Microstructure and corrosion resistance of phytic acid conversion coatings for magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Cui Xiufang [School of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Li Qingfen [School of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Li Ying; Wang Fuhui [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Jin Guo [School of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China)], E-mail: jg97721@yahoo.com.cn; Ding Minghui [School of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China)

    2008-12-30

    In this paper, a new innoxious and pollution-free chemical protective coating for magnesium alloys, phytic acid conversion coating, was prepared. The conversion coatings are found to have high cover ratio and no cracks are found by atomic force microscopes (AFM) and scanning electron microscopy (SEM). The main elements of the conversion coatings are Mg, Al, O, P and C by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The chemical state of the elements in the coatings was also investigated by Fourier transform infrared spectroscopy (FTIR). AES depth profile analysis suggests that the thickness of the conversion coating is about 340 nm. The corrosion resistance of the coatings was evaluated by polarization curves. The results indicate that the corrosion resistance for the conversion coated AZ91D magnesium alloys in 3.5% NaCl solution increases markedly. The mechanisms of corrosion resistance and coatings formation are also discussed.

  20. Use of polyurea from urea for coating of urea granules.

    Science.gov (United States)

    Lu, Panfang; Zhang, Yanfei; Jia, Cong; Li, Yufeng; Mao, Zhiquan

    2016-01-01

    A new type of controlled release fertilizers coated with polyurea was prepared. The granulated urea was firstly changed into a liquid urea by heating as the coating liquid. By spraying uniformly the urea was coated with the polyurea synthesized by the reaction of isocyanates with a liquid urea. The effects of different modifiers on N release characteristics of polyurea-coated urea (PCU) were studied. The morphology and chemical structure of PCU coating materials was investigated by SEM and FTIR. We studied the nitrogen release characteristics of the PCU applied in both water and soil, and the biodegradability of PCU coating after buried in soil. The results showed that PCU reduced nitrogen release rate and exhibited excellent controlled release property. The PCU coating materials could biodegrade in soil. This indicated that the low cost PCU products from urea are expected to use in agricultural and horticultural applications. PMID:27119061

  1. Interactions between the glass fiber coating and oxidized carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Ku-Herrera, J.J., E-mail: jesuskuh@live.com.mx [Centro de Investigación Científica de Yucatán A.C., Unidad de Materiales, Calle 43 No.130, Col. Chuburná de Hidalgo. C.P., 97200 Mérida, Yucatán (Mexico); Avilés, F., E-mail: faviles@cicy.mx [Centro de Investigación Científica de Yucatán A.C., Unidad de Materiales, Calle 43 No.130, Col. Chuburná de Hidalgo. C.P., 97200 Mérida, Yucatán (Mexico); Nistal, A. [Instituto de Cerámica y Vidrio (ICV-CSIC), Kelsen 5, 28049 Madrid (Spain); Cauich-Rodríguez, J.V. [Centro de Investigación Científica de Yucatán A.C., Unidad de Materiales, Calle 43 No.130, Col. Chuburná de Hidalgo. C.P., 97200 Mérida, Yucatán (Mexico); Rubio, F.; Rubio, J. [Instituto de Cerámica y Vidrio (ICV-CSIC), Kelsen 5, 28049 Madrid (Spain); Bartolo-Pérez, P. [Departamento de Física Aplicada, Cinvestav, Unidad Mérida, C.P., 97310 Mérida, Yucatán (Mexico)

    2015-03-01

    Graphical abstract: - Highlights: • Oxidized multiwall carbon nanotubes (MWCNTs) were deposited onto E-glass fibers. • The role of the fiber coating on the deposition of MWCNTs on the fibers is studied. • A rather homogeneous deposition of MWCNTs is achieved if the coating is maintained. • Multiple oxygen-containing groups were found in the analysis of the fiber coating. • Evidence of chemical interaction between MWCNTs and the fiber coating was found. - Abstract: Chemically oxidized multiwall carbon nanotubes (MWCNTs) were deposited onto commercial E-glass fibers using a dipping procedure assisted by ultrasonic dispersion. In order to investigate the role of the fiber coating (known as “sizing”), MWCNTs were deposited on the surface of as-received E-glass fibers preserving the proprietary coating as well as onto glass fibers which had the coating deliberately removed. Scanning electron microscopy and Raman spectroscopy were used to assess the distribution of MWCNTs onto the fibers. A rather homogeneous coverage with high density of MWCNTs onto the glass fibers is achieved when the fiber coating is maintained. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and nuclear magnetic resonance (NMR) analyses of the chemical composition of the glass fiber coating suggest that such coating is a complex mixture with multiple oxygen-containing functional groups such as hydroxyl, carbonyl and epoxy. FTIR and XPS of MWCNTs over the glass fibers and of a mixture of MWCNTs and fiber coating provided evidence that the hydroxyl and carboxyl groups of the oxidized MWCNTs react with the oxygen-containing functional groups of the glass fiber coating, forming hydrogen bonding and through epoxy ring opening. Hydrogen bonding and ester formation between the functional groups of the MWCNTs and the silane contained in the coating are also possible.

  2. Effect of SiO2 Coating Combined with Chemical Treatment by Phosphoric Acid on Oxidation Resistance of Ti-6Al-4V Alloy%磷酸表面处理复合SiO2涂层对Ti-6Al-4V合金抗氧化性能的影响

    Institute of Scientific and Technical Information of China (English)

    任保轶; 刘子孺; 高艳慧; 张学军

    2013-01-01

    The effects of phosphoric acid chemical treatment and composite SiO2 coating on oxidation resistance of Ti-6Al-4V alloy were investigated.Results show that,the average oxidation rate of the Ti-6Al-4V alloy treated by phosphoric acid decreases nearly by 75% in comparison with the blank samples at 600℃ after 24h oxidation in air.The oxidation rate of composite SiO2 coating sample reduces one order of magnitude in comparison with the blank sample oxidation for 100h at the same condition.The composite SiO2 coating has better anti-oxidation ability than phosphoric acid treatment.The compactness of the oxide scale of the composite SiO2 coating and the phosphoric acid treatment samples increases,and a good adhesion with the substrate is shown,the volume fractions of TiO2 in oxidation films reduce both phosphoric acid chemical treatment and composite SiO2 coating samples.The in-diffusion of O and out-diffusion of Ti are restrained because of the formation of TiP2O7 phase and deposit SiO2 coating.%研究磷酸表面处理和复合SiO2涂层对Ti-6Al-4V合金600℃下空气中抗氧化性能的影响.结果表明:600℃氧化24h后,磷酸表面处理使Ti-6Al-4V合金平均氧化速率下降了近75%,复合非晶SiO2涂层样品600℃等温氧化100h后,平均氧化速率比空白样品降低一个数量级,抗氧化性能与单独的磷酸处理比较进一步提高.磷酸表面处理和复合SiO2涂层样品的氧化膜致密性增强且与基体的黏附性良好,二者氧化膜中TiO2的体积分数均低于空白样品.磷酸表面处理形成的TiP2O7层与SiO2涂层共同抑制了O的内扩散和Ti的外扩散.

  3. COMPARISON OF SOL-GEL SILICATE COATINGS ON Ti SUBSTRATE

    Directory of Open Access Journals (Sweden)

    DIANA HORKAVCOVÁ

    2012-12-01

    Full Text Available The objective of the submitted work was to prepare and to characterize two types of silicate coatings prepared by the sol-gel method using the dip-coating technique on a titanium substrate. Efforts have been made to use mechanical properties of bio-inert titanium and bioactive properties of a silicate layer enriched with an admixture of compounds identified below. The first group consisted of silicate coatings containing silver, brushite and monetite. The other group of silicate coatings contained calcium nitrate and triethyl phosphate. Mechanically and chemically treated titanium substrates were dipped into sols and dried and fired. Silicate coatings from the first group were also chemically treated in 10 mol.l-1 solution of sodium hydroxide. All coatings were measured to determine their adhesive and bioactive properties and furthermore the antibacterial properties were tested in the case of first group. Surfaces of the coated substrates were investigated after the firing and after the individual tests with optical and electron microscopy and X-ray microdiffraction. A tape test demonstrated excellent adhesive property of all coatings to the substrate, classified with degree 5. A static in vitro test demonstrated bioactivity of nearly all the coatings. The basic silicate coating from the first group and one type of coating from the second group were identified as inert. Antibacterial properties of silicate coatings containing silver showed to be different when tested against Escherichia coli bacteria. A complete inhibition of the growth of bacteria under our experimental conditions was observed for the coating containing silver and monetite and a partial inhibition of the growth of bacteria for coatings containing silver and silver in combination with brushite.

  4. European coatings conference - Marine coatings. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This volume contains 13 lectures (manuscripts or powerpoint foils) with the following topics: 1. Impact of containerization on polyurethane and polyurea in marine and protective coatings (Malte Homann); 2. The application of combinatorial/high-throughput methods to the development of marine coatings (Bret Chisholm); 3. Progress and perspectives in the AMBIO (advanced nanostructured surfaces for the control of biofouling) Project (James Callow); 4. Release behaviour due to shear and pull-off of silicone coatings with a thickness gradient (James G. Kohl); 5. New liquid rheology additives for high build marine coatings (Andreas Freytag); 6. Effective corrosion protection with polyaniline, polpyrrole and polythiophene as anticorrosice additives for marine paints (Carlos Aleman); 7. Potential applications of sol gel technology for marine applications (Robert Akid); 8: Performance of biocide-free Antifouling Coatings for leisure boats (Bernd Daehne); 9. Novel biocidefree nanostructured antifouling coatings - can nano do the job? (Corne Rentrop); 10. One component high solids, VOC compliant high durability finish technology (Adrian Andrews); 11. High solid coatings - the hybrid solution (Luca Prezzi); 12. Unique organofunctional silicone resins for environmentally friendly high-performance coatings (Dieter Heldmann); 13. Silicone-alkyd paints for marine applications: from battleship-grey to green (Thomas Easton).

  5. Nanoscale Reinforced, Polymer Derived Ceramic Matrix Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Rajendra Bordia

    2009-07-31

    The goal of this project was to explore and develop a novel class of nanoscale reinforced ceramic coatings for high temperature (600-1000 C) corrosion protection of metallic components in a coal-fired environment. It was focused on developing coatings that are easy to process and low cost. The approach was to use high-yield preceramic polymers loaded with nano-size fillers. The complex interplay of the particles in the polymer, their role in controlling shrinkage and phase evolution during thermal treatment, resulting densification and microstructural evolution, mechanical properties and effectiveness as corrosion protection coatings were investigated. Fe-and Ni-based alloys currently used in coal-fired environments do not possess the requisite corrosion and oxidation resistance for next generation of advanced power systems. One example of this is the power plants that use ultra supercritical steam as the working fluid. The increase in thermal efficiency of the plant and decrease in pollutant emissions are only possible by changing the properties of steam from supercritical to ultra supercritical. However, the conditions, 650 C and 34.5 MPa, are too severe and result in higher rate of corrosion due to higher metal temperatures. Coating the metallic components with ceramics that are resistant to corrosion, oxidation and erosion, is an economical and immediate solution to this problem. Good high temperature corrosion protection ceramic coatings for metallic structures must have a set of properties that are difficult to achieve using established processing techniques. The required properties include ease of coating complex shapes, low processing temperatures, thermal expansion match with metallic structures and good mechanical and chemical properties. Nanoscale reinforced composite coatings in which the matrix is derived from preceramic polymers have the potential to meet these requirements. The research was focused on developing suitable material systems and

  6. Variable emittance behavior of smart radiative coating

    Science.gov (United States)

    Guo, Li; Fan, Desong; Li, Qiang

    2016-02-01

    Smart radiative coating on yttria stabilized zirconia (YSZ) substrate was prepared by the sol-gel La{}1-xSr x MnO3 (x = 0.125, 0.175 and 0.2) nanoparticles and the binder composed of terpineol and ethyl cellulose. The crystallized structure, grain size, chemical compositions, magnetization and the surface morphology were characterized. The thermal radiative properties of coating in the infrared range was evaluated from infrared reflectance spectra at various temperatures. A single perovskite structure is detected in sol-gel nanoparticles with size 200 nm. Magnetization measurement reveals that room temperature phase transition samples can be obtained by appropriate Sr substitution. The influence of surface conditions and sintering temperature on the emittance of coating was observed. For rough coatings with root-mean-square roughness 640 nm (x = 0.125) and 800 nm (x = 0.175) , its emittance increment is 0.24 and 0.26 in in the temperature range of 173-373 K. Increasing sintering temperature to 1673 K, coating emittance variation improves to 0.3 and 0.302 respectively. After mechanical polishing treatment, the emittance increment of coatings are enhanced to 0.31 and 0.3, respectively. The results suggested that the emittance variation can be enhanced by reducing surface roughness and increasing sintering temperature of coating.

  7. Removal Of Optical Coatings Without Polishing

    Science.gov (United States)

    Gourley, Helen

    1980-11-01

    A process for removing antireflection, mirror and polarizer coatings has been developed at ILC, based on work begun by LLL (Applied Optics Vol. 17, No. 12, 15 June 1978 - "Notes on Optical Coating Removal", N.J. Brown). Because of the danger (personnel hazard) involved in the hydrofluoric acid process, we employed an ammonium bifluoride solution, combined with various polishing components. The substrates, generally BK7, are fairly soft and also sensitive to chemical action. Therefore we have limited our polishing materials to aluminum oxide powder graded at 0.1 pm or smaller. For some coatings, no polishing material is used, as the ammonium bifluoride solution is adequate to remove the coating. The resulting clean surface is washed and neutralized, and is then ready for recoating.

  8. Induction surface hardening of hard coated steels

    DEFF Research Database (Denmark)

    Pantleon, Karen; Kessler, Olaf; Hoffmann, Franz;

    1999-01-01

    . The effect of induction surface hardening on the properties of the coating-substrate-systems is mainly characterized using investigations of microstructure and chemical composition as well as measurements of hardness and residual stresses in dependence on the distance from the surface. Furthermore......The deposition of hard coatings with CVD-processes is commonly used to improve the wear resistance e.g. of tool steels in forming. The advantages of CVD are undisputed (high deposition rates with simple equipment, excellent coating properties). Nevertheless, the disadvantage of the CVD......-process is the high deposition temperature, consequently the properties of steel substrates are negatively influenced. Therefore, a subsequent heat treatment of the coated steels is necessary to restore the properties of steels ready for operation. Induction surface hardening is used as a method of heat treatment...

  9. Investigation of sol-gel antireflective coatings

    International Nuclear Information System (INIS)

    Very high power laser systems present material design challenges which often approach the inherent optical survival strength of components. Optical coatings in the UV region suffer from anomalously high absorption and scattering in the deposited layers. The losses caused by these effects are often unacceptable or, in the case of absorption, usually fatal to the absorbing coatings. Unfortunately, no metals exist that have high enough reflectivities in the UV to serve as uncoated mirrors as they normally do in the CO2 region of the infrared. Adequate multilayer dielectric coatings are therefore critically important for the development and utilization of UV lasers. The same could be said for relfection suppressing antireflective coatings in that wavelength range. Antireflective properties of gradientindex designs have been rediscovered and their potential for resolving UV laser design difficulties has been vigorously tested. These antireflective properties have been attained on glass or fused silica surfaces by chemical surface treatments

  10. PIT Coating Requirements Analysis

    International Nuclear Information System (INIS)

    This study identifies the applicable requirements for procurement and installation of a coating intended for tank farm valve and pump pit interior surfaces. These requirements are intended to be incorporated into project specification documents and design media. This study also evaluates previously recommended coatings and identifies requirement-compliant coating products

  11. PIT Coating Requirements Analysis

    Energy Technology Data Exchange (ETDEWEB)

    MINTEER, D.J.

    2000-10-20

    This study identifies the applicable requirements for procurement and installation of a coating intended for tank farm valve and pump pit interior surfaces. These requirements are intended to be incorporated into project specification documents and design media. This study also evaluates previously recommended coatings and identifies requirement-compliant coating products.

  12. 放热体系对镁合金反应热喷涂陶瓷涂层耐蚀性能的影响%Influence of exothermic chemical system on corrosion resistance of reaction thermal spraying ceramic coating prepared on magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    董世知; 周鹏; 宋佳; 窦梓航; 于浩

    2012-01-01

    Influence of exothermic chemical system on corrosion resistance of ceramic coatings prepared by reaction thermal-spraying method with the same aggregate and different exothermic chemical system A1/CuO and A1-TiO2-B203 was studied by comparing morphology, XRD, porosity, acid-resistance (5% acetic acid solution), salt-resistance (3.5 % NaC1 solution) respectively. The test results show that compared to matrix AZ31 B, corrosion-resistance of ceramic coating with A1/CuO exothermic chemical system is improved by 23.37 and 16.33 times, whereas A1-TiO2-B203 exothermic chemical system just about 12.91 and 7.46 times. Ceramic coating with A1/CuO exothermic chemical system exhibits better corrosion-resistance than A1-TiO2-B203 exothermic chemical system.%采用相同的陶瓷骨料和热喷涂工艺,放热体系分别为Al/CuO和Al-TiO2-B2O3,制备热喷涂陶瓷涂层,通过对涂层表面形貌观察、物相分析、孔隙率,耐酸性(5%醋酸),耐盐性(3.5%NaCl)测试比较放热体系对陶瓷涂层耐蚀性能影响。结果表明:与基体AZ31B相比,采用Al-CuO为放热体系的陶瓷涂层耐酸性提高23.37倍,耐盐性提高16.33倍,Al-TiO2-B2O3放热体系陶瓷涂层的耐酸性提高12.91倍,耐盐性提高7.46倍,Al-CuO放热体系陶瓷涂层耐蚀性优于Al-TiO2-B2O3放热体系陶瓷涂层。

  13. Optical Properties of Window Coatings

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Window coating used for the building in recent years is described. Important design principles, practical coating materials, and attainable optical properties for research-type coatings are introduced. Discussion is carried out on the spectrally selective coatings, the electrochromic coatings, and the thermochromic coatings.

  14. Microstructural Study of Titanium Carbide Coating on Cemented Carbide

    DEFF Research Database (Denmark)

    Vuorinen, S.; Horsewell, Andy

    1982-01-01

    Titanium carbide coating layers on cemented carbide substrates have been investigated by transmission electron microscopy. Microstructural variations within the typically 5µm thick chemical vapour deposited TiC coatings were found to vary with deposit thickness such that a layer structure could...... be delineated. Close to the interface further microstructural inhomogeneities were obsered, there being a clear dependence of TiC deposition mechanism on the chemical and crystallographic nature of the upper layers of the multiphase substrate....

  15. Corrosion protective coating for metallic materials

    Science.gov (United States)

    Buchheit, Rudolph G.; Martinez, Michael A.

    1998-01-01

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

  16. ATHENA optimized coating design

    DEFF Research Database (Denmark)

    Ferreira, Desiree Della Monica; Christensen, Finn Erland; Jakobsen, Anders Clemen;

    2012-01-01

    The optimization of coating design for the ATHENA mission si described and the possibility of increasing the telescope effective area in the range between 0.1 and 10 keV is investigated. An independent computation of the on-axis effective area based on the mirror design of ATHENA is performed...... in order to review the current coating baseline. The performance of several material combinations, considering a simple bi-layer, simple multilayer and linear graded multilayer coatings are tested and simulation of the mirror performance considering both the optimized coating design and the coating...

  17. Antibacterial polymer coatings.

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Mollye C.; Allen, Ashley N.; Barnhart, Meghan; Tucker, Mark David; Hibbs, Michael R.

    2009-09-01

    A series of poly(sulfone)s with quaternary ammonium groups and another series with aldehyde groups are synthesized and tested for biocidal activity against vegetative bacteria and spores, respectively. The polymers are sprayed onto substrates as coatings which are then exposed to aqueous suspensions of organisms. The coatings are inherently biocidal and do not release any agents into the environment. The coatings adhere well to both glass and CARC-coated coupons and they exhibit significant biotoxicity. The most effective quaternary ammonium polymers kills 99.9% of both gram negative and gram positive bacteria and the best aldehyde coating kills 81% of the spores on its surface.

  18. DEVELOPMENT OF GOLD COATED THREADS AND IMPLEMENTATION INTO A WEARABLE SYSTEM

    OpenAIRE

    Georgios PRINIOTAKIS; TZERACHOGLOU Anastasios; Ioannis CHRONIS; Van Langenhove, Lieva; Westbroek, Philippe; Nyokong, Tebello

    2012-01-01

    The paper presents the coating of commercially available textile threads with metals in order to provide it with electroconductive properties. This can be done in different ways such as metallization, electroless deposition, electrodeposition, chemical coating, carbon and metallic compound inclusion and application of electroconductive composites. However, by using the coating method (through depositing layers), high performance textile threads are made electroconductive without losing their ...

  19. Durable and self-healing superamphiphobic coatings repellent even to hot liquids.

    Science.gov (United States)

    Li, Bucheng; Zhang, Junping

    2016-02-14

    Durable and self-healing superamphiphobic coatings with high repellency to both cool and hot liquids are successfully prepared on various substrates by the combination of rodlike palygorskite and organosilanes via spray-coating. The coatings feature high mechanical, environmental and chemical durability, and are self-healing. PMID:26758697

  20. Interfacial Characterization of Rigid Polymer Coatings

    Science.gov (United States)

    DeNolf, Garret C.

    In order to enhance the performance and durability of today's polymer coatings it is pivotal to be able to characterize their mechanical and chemical properties, with emphasized importance on coating-substrate interfaces which are common points of material failure. The purpose of this thesis was to develop and demonstrate novel characterization methods to measure the interfacial and bulk properties of these polymer films and improve the overall understanding of these materials. The first portion of this thesis explores a new peel test technique to measure the adhesion between substrates and coatings. The employed method examines the effect of processing conditions and substrate treatment on the adhesion of polyurethane coatings. This technique successfully quantifies the adhesion of polyurethane coatings to a variety of treated substrates and at multiple curing temperatures. The second thrust of this thesis involves the utilization of a quartz crystal microbalance instrument to characterize the bulk rheological properties of polymer films and coatings in situ. This novel method enables the examination of the effect of temperature and mixing stoichiometry on the rheological properties of curing polyurethane coatings and polymer films. This analysis is extended to measure the curing and aging of paint systems relevant to the art conservation scientific community. The final portion of this thesis focuses on understanding the effect of pH on the interfacial swelling of polymer films in aqueous environments. The quartz crystal microbalance is used to characterize the swelling of interfacial polymer films as water reaches the interface, and the corresponding permeability and osmotic pressure provides insight into the mechanisms of delamination and adhesive failure of coatings attached to metal surfaces. The novel methods and calculations established in this thesis enable precise measurements of coating interfaces and rheological properties and have considerable potential

  1. Properties of niobium coatings electrodeposited from fluoride melts

    International Nuclear Information System (INIS)

    Certain properties (chemical purity, continuity, surface roughness, ultimate strength, specific electric resistance) of niobium coatings produced by means of (Li-Na-K)Feut - K2NbF7 melt electrolysis, depending on deposition conditions, have been studied. It is shown that the coatings have a high continuity, their thickness being in excess of 5 μm. Interrelation between roughness parameters and conditions of the coating production has been considered. Influence of electrolysis conditions on mechanical and electric properties of the coatings has been ascertained. 23 refs., 7 figs

  2. Coated Aerogel Beads

    Science.gov (United States)

    Littman, Howard (Inventor); Plawsky, Joel L. (Inventor); Paccione, John D. (Inventor)

    2014-01-01

    Methods and apparatus for coating particulate material are provided. The apparatus includes a vessel having a top and a bottom, a vertically extending conduit having an inlet in the vessel and an outlet outside of the vessel, a first fluid inlet in the bottom of the vessel for introducing a transfer fluid, a second fluid inlet in the bottom of the vessel for introducing a coating fluid, and a fluid outlet from the vessel. The method includes steps of agitating a material, contacting the material with a coating material, and drying the coating material to produce a coated material. The invention may be adapted to coat aerogel beads, among other materials. A coated aerogel bead and an aerogel-based insulation material are also disclosed.

  3. Anticorrosive coatings: a review

    DEFF Research Database (Denmark)

    Sørensen, Per Aggerholm; Kiil, Søren; Dam-Johansen, Kim;

    2009-01-01

    of volatile organic compounds (VOCs) have caused significant changes in the anticorrosive coating industry. The requirement for new VOC-compliant coating technologies means that coating manufacturers can no longer rely on the extensive track record of their time-served products to convince consumers......, and inhibitive coatings are outlined. In the past decades, several alternatives to organic solvent-borne coatings have reached the commercial market. This review also presents some of these technologies and discusses some of their advantages and limitations. Finally, some of the mechanisms leading to degradation...... of their suitability for use. An important aspect in the development of new VOC-compliant, high-performance anticorrosive coating systems is a thorough knowledge of the components in anticorrosive coatings, their interactions, their advantages and limitations, as well as a detailed knowledge on the failure modes...

  4. 磁控溅射法制备CrTiAlCN镀层中主要元素的化学态%Chemical states of the main elements in CrTiAlCN coating based on magnetron sputtering plating technique

    Institute of Scientific and Technical Information of China (English)

    胡鹏飞; 蒋百灵; 李洪涛

    2011-01-01

    The CrTiAlCN coating was deposited on single crystal silicon( 111 ) substrate using closed-field unbalanced magnetron sputtering ion plating technique. The phase constitution of the CrTiAlCN coating with different carbon target current and the chemical states of the main elements in the coating were investigated. The analysis of XRD shows that the coating transforms from crystalline state to amorphous state when the carbon target current increases from 0 A to 1.5 A. The analysis of XPS shows that the carbon exists mainly as the forms of C-C, C-Cr and C-Ti bond, the nitrogen element exists mainly as the forms of CrN, Cr2 N and TiN, the chrome element exists mainly as the forms of CrN,Cr2 N and CrCx.%采用闭合场非平衡磁控溅射离子镀技术在单晶硅(111)衬底上沉积了CrTiAlCN镀层,研究了不同C靶电流CrTiAlCN物相组成,并分析了镀层中主要元素的化学态.X射线衍射分析表明,当C靶电流Ic从0增大到2.4 A时,镀层由晶态向非晶态转变;X射线光电子能谱分析表明,碳元素主要以C-C-C-Cr和C-Ti键形式存在;N元素是主要以CrN、Cr2N和TiN的形式存在;Cr元素主要以CrN、Cr2N及CrCx的形式存在.

  5. Facile approach in fabricating superhydrophobic SiO{sub 2}/polymer nanocomposite coating

    Energy Technology Data Exchange (ETDEWEB)

    Chen Hengzhen [Laboratory of Special Functional Materials, Henan University, Kaifeng 475001 (China); Zhang Xia, E-mail: zhangxia0307@yahoo.com.cn [Laboratory of Special Functional Materials, Henan University, Kaifeng 475001 (China); Zhang Pingyu; Zhang Zhijun [Laboratory of Special Functional Materials, Henan University, Kaifeng 475001 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Fluorine-free superhydrophobic SiO{sub 2}/polymer composite coatings are fabricated by a simple spin-coating method without any surface chemical modification. Black-Right-Pointing-Pointer The SiO{sub 2}/polymer coatings show long-term stability in the condition of continuous contact with corrosive water. Black-Right-Pointing-Pointer The coating can be fabricated on various metal substrates to prevent metal from corrosion. - Abstract: We have developed a facile spin-coating method to prepare water-repellent SiO{sub 2}/polymer composite coating without any surface chemical modification. The wettability can be adjusted by controlling the content of SiO{sub 2} nanoparticles. The coating demonstrates sustainable superhydrophobicity in the condition of continuous contact with corrosive liquids. Importantly, the coating can be fabricated on various metal substrates to prevent metal from corrosion.

  6. Molecularly Imprinted Polymer Coated on Stainless Steel Fiber

    Institute of Scientific and Technical Information of China (English)

    Hu XiaoGang; Dai GuiMei; Huang JiaJing

    2009-01-01

    @@ With characteristics of specific selectivity,good chemical stability and easy preparation,molecularly imprinted polymer (MIP) has been used as the recognition materials m various fields ~([1,2]).Recently,the application of MIP in the sample pre-treatment techniques such as SPME was attractive ~([3,4]).For analysis of complicated samples,the interference matrix would be reduced obviously with the MIP-coated SPME fiber~([5-7]).Because MIPs were coated on the surface of silica fiber through chemical bonding,those fibers could be used for over 80 times without obvious losing of surface quality and extraction performance of MIP coatings.

  7. COMPOSITION AND STRUCTURAL STUDIES OF STRONG GLOW DISCHARGE POLYMER COATINGS

    Energy Technology Data Exchange (ETDEWEB)

    CZECHOWICZ, DG; CASTILLO, ER; NIKROO, A

    2002-04-01

    OAK A271 COMPOSITION AND STRUCTURAL STUDIES OF STRONG GLOW DISCHARGE POLYMER COATINGS. An investigation of the chemical composition and structure of strong glow discharge (GDP) polymer shells made for cryogenic experiments at OMEGA is described. The investigation was carried out using combustion and Fourier Transform Infrared Spectroscopy (FTIR) analysis. The strongest coatings were observed to have the lowest hydrogen content or hydrogen/carbon H/C ratio, whereas the weakest coatings had the highest hydrogen content or H/C ratio. Chemical composition results from combustion were used to complement FTIR analysis to determine the relative hydrogen content of as-fabricated coatings. Good agreement was observed between composition results obtained from combustion and FTIR analysis. FTIR analysis of coating structures showed the strongest coatings to have less terminal methyl groups and a more double bond or olefinic structure. Strong GDP coatings that were aged in air react more with oxygen and moisture than standard GDP coatings. In addition to a more olefinic structure, there may also be more free-radial sites present in strong GDP coatings, which leads to greater oxygen uptake.

  8. Mechanical pretreatment for improved adhesion of diamond coatings

    International Nuclear Information System (INIS)

    Diamond coatings are mainly used in cutting processes due to their tribological characteristics. They show a high hardness, low friction coefficient, high wear resistance and good chemical inertness. In relation to polycrystalline diamond (PCD)-tipped cutting inserts, especially the advantageous chemical stability of diamond coatings is superior as no binder phases between diamond grains are used. However, the deposition of adherent high-quality diamond coatings has been found difficult. Thus, substrate pretreatment is utilised to improve film adhesion. This investigation is based on water peening of the substrate material before coating. The investigation revealed best results for diamond film adhesion on pretreated substrates compared to conventional diamond coatings on cemented carbide tools applied with the CVD hot-filament process. In final cutting tests with increased film adhesion trough water peened cutting tools an improved wear behavior was detected. (orig.)

  9. Tortuous path chemical preconcentrator

    Science.gov (United States)

    Manginell, Ronald P.; Lewis, Patrick R.; Adkins, Douglas R.; Wheeler, David R.; Simonson, Robert J.

    2010-09-21

    A non-planar, tortuous path chemical preconcentrator has a high internal surface area having a heatable sorptive coating that can be used to selectively collect and concentrate one or more chemical species of interest from a fluid stream that can be rapidly released as a concentrated plug into an analytical or microanalytical chain for separation and detection. The non-planar chemical preconcentrator comprises a sorptive support structure having a tortuous flow path. The tortuosity provides repeated twists, turns, and bends to the flow, thereby increasing the interfacial contact between sample fluid stream and the sorptive material. The tortuous path also provides more opportunities for desorption and readsorption of volatile species. Further, the thermal efficiency of the tortuous path chemical preconcentrator is comparable or superior to the prior non-planar chemical preconcentrator. Finally, the tortuosity can be varied in different directions to optimize flow rates during the adsorption and desorption phases of operation of the preconcentrator.

  10. Studies on Properties and Structure of Electroless Plating Tin Coating

    Institute of Scientific and Technical Information of China (English)

    XU Rui-dong; GUO Zhong-cheng; ZHU Xiao-yun

    2004-01-01

    The composition and structure of electroless tin coating were analyzed by SEM and X-ray diffraction. In the meantime, porosity, solderability and extensibility were determined by physical and chemical methods. The results showed that the porosity of the tin coating increases with the rise of bath temperature and decreases as the plating time rises. Solderability is improved with the rise of thickness of tin coating, and decreases when the tin deposit is heated at 180 ~ 200 ℃. The crystalline grain size becomes bigger and bigger with increasing plating time or bath temperature or coating thickness. X-ray diffraction indicates that only Cu and β-Sn phases show up in the diffraction patterns. Tin coating has a strong joint force with copper substrate and excellent function of electrochemical protection as anode coating.

  11. High Critical Current Coated Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Paranthaman, M. P.; Selvamanickam, V. (SuperPower, Inc.)

    2011-12-27

    One of the important critical needs that came out of the DOE’s coated conductor workshop was to develop a high throughput and economic deposition process for YBCO. Metal-organic chemical vapor deposition (MOCVD) technique, the most critical steps in high technical micro fabrications, has been widely employed in semiconductor industry for various thin film growth. SuperPower has demonstrated that (Y,Gd)BCO films can be deposited rapid with world record performance. In addition to high critical current density with increased film thickness, flux pinning properties of REBCO films needs to be improved to meet the DOE requirements for various electric-power equipments. We have shown that doping with Zr can result in BZO nanocolumns, but at substantially reduced deposition rate. The primary purpose of this subtask is to develop high current density MOCVD-REBCO coated conductors based on the ion-beam assisted (IBAD)-MgO deposition process. Another purpose of this subtask is to investigate HTS conductor design optimization (maximize Je) with emphasis on stability and protection issues, and ac loss for REBCO coated conductors.

  12. Exploring float glass powder as corrosion resistant glass coating applied to concrete by flame spraying

    OpenAIRE

    Zhang, Li

    2014-01-01

    Float glass was chosen as precursor material to generate protective coatings on concrete structures against chemical attack. The method of application was flame spraying. The feedstock for flame spraying was in form of powders. The preparation methods (dry ball milling and spray drying) affected the morphology, the particle size distribution and the spray ability of the coating powders. Compared to as-sprayed coatings from dry ball milled powders, coatings from the spray dried powders had a m...

  13. Self-Cleaning Photocatalytic Polyurethane Coatings Containing Modified C60 Fullerene Additives

    OpenAIRE

    Jeffrey G. Lundin; Spencer L. Giles; Robert F. Cozzens; James H. Wynne

    2014-01-01

    Surfaces are often coated with paint for improved aesthetics and protection; however, additional functionalities that impart continuous self-decontaminating and self-cleaning properties would be extremely advantageous. In this report, photochemical additives based on C60 fullerene were incorporated into polyurethane coatings to investigate their coating compatibility and ability to impart chemical decontaminating capability to the coating surface. C60 exhibits unique photophysical properties,...

  14. DLC coatings for machine elements application

    International Nuclear Information System (INIS)

    The paper presented the most important conditions determining capability of a C, a-C:H and X-C:H (where X = W, Ti, Cr, Si) coatings, commonly known as DLC (Diamond-Like Carbon) for machine elements application. The X-C:H(X = W, Ti, Si) coatings containing 5-7 at.% of X component, produced by pulsed reactive magnetron sputtering (RMS), revealed the most favourable tribological properties, i.e. the low value of dry friction coefficient (f vc-7 mm3N-1m-1). Chemical composition analyses carried out on worn surface of bearing steel counterpart shows, that very good tribological properties of DLC coatings are connecting with slip effects prevailing in a tribolayer in consequence of graphitization and oxidation. W-WC/a-C:H-W5%-C:H gradient and WC/a-C:H/a-C:H multilayer coatings composed of many alternatively deposited WC/a-C:H nanocomposite and a-C:H amorphous coatings are marked by a favourable combination of desirable tribological properties, high adhesion and crack resistance. An interlayer film between the substrate and the coating, have the crucial effects on the adhesion and crack resistance, and especially favourable is application of chromium film. (author)

  15. Titanate nanotube coatings on biodegradable photopolymer scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Beke, S., E-mail: szabolcs.beke@iit.it [Department of Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Kőrösi, L. [Department of Biotechnology, Nanophage Therapy Center, Enviroinvest Corporation, Kertváros u. 2, H-7632, Pécs (Hungary); Scarpellini, A. [Department of Nanochemistry, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Anjum, F.; Brandi, F. [Department of Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy)

    2013-05-01

    Rigid, biodegradable photopolymer scaffolds were coated with titanate nanotubes (TNTs) by using a spin-coating method. TNTs were synthesized by a hydrothermal process at 150 °C under 4.7 bar ambient pressure. The biodegradable photopolymer scaffolds were produced by mask-assisted excimer laser photocuring at 308 nm. For scaffold coating, a stable ethanolic TNT sol was prepared by a simple colloid chemical route without the use of any binding compounds or additives. Scanning electron microscopy along with elemental analysis revealed that the scaffolds were homogenously coated by TNTs. The developed TNT coating can further improve the surface geometry of fabricated scaffolds, and therefore it can further increase the cell adhesion. Highlights: ► Biodegradable scaffolds were produced by mask-assisted UV laser photocuring. ► Titanate nanotube deposition was carried out without binding compounds or additives. ► The titanate nanotube coating can further improve the surface geometry of scaffolds. ► These reproducible platforms will be of high importance for biological applications.

  16. Titanate nanotube coatings on biodegradable photopolymer scaffolds

    International Nuclear Information System (INIS)

    Rigid, biodegradable photopolymer scaffolds were coated with titanate nanotubes (TNTs) by using a spin-coating method. TNTs were synthesized by a hydrothermal process at 150 °C under 4.7 bar ambient pressure. The biodegradable photopolymer scaffolds were produced by mask-assisted excimer laser photocuring at 308 nm. For scaffold coating, a stable ethanolic TNT sol was prepared by a simple colloid chemical route without the use of any binding compounds or additives. Scanning electron microscopy along with elemental analysis revealed that the scaffolds were homogenously coated by TNTs. The developed TNT coating can further improve the surface geometry of fabricated scaffolds, and therefore it can further increase the cell adhesion. Highlights: ► Biodegradable scaffolds were produced by mask-assisted UV laser photocuring. ► Titanate nanotube deposition was carried out without binding compounds or additives. ► The titanate nanotube coating can further improve the surface geometry of scaffolds. ► These reproducible platforms will be of high importance for biological applications

  17. Film coatings for oral pulsatile release.

    Science.gov (United States)

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

    2013-12-01

    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

  18. Preliminary coating design and coating developments for ATHENA

    DEFF Research Database (Denmark)

    Jakobsen, Anders Clemen; Ferreira, Desiree Della Monica; Christensen, Finn Erland;

    2011-01-01

    We present initial novel coating design for ATHENA. We make use of both simple bilayer coatings of Ir and B4C and more complex constant period multilayer coatings to enhance the effective area and cover the energy range from 0.1 to 10 keV. We also present the coating technology used for these...... designs and present test results from coatings....

  19. Effect of Chemical Vapor Deposition Temperature on Composition,Microstructure and Surface Morphology of Tantalum Coatings%CVD温度对钽涂层组成、显微组织及形貌的影响

    Institute of Scientific and Technical Information of China (English)

    蔡宏中; 魏巧灵; 陈力; 王云; 胡昌义

    2012-01-01

    利用TaCl2-H2-HCl反应体系,采用冷壁式化学气相沉积法(CVD)在钼基体表面沉积钽涂层.通过X射线衍射仪、金像显微镜及扫描电镜等手段,对不同沉积温度下钽涂层的组成、组织及形貌进行了研究.结果表明:在1000~1300℃范围内,钽沉积层的相组成无变化,而对择优生长有一定影响;钽沉积层晶粒尺寸随沉积温度的升高而增大;钽沉积层表面颗粒呈金字塔形多面体且随沉积温度的升高而增大.%The Ta coating on the surface of Mo matrix was prepared by cold-wall CVD in TaCl2-H2-HCl system. The influences of temperature on phase composition, microstructures and surface morphology of the coating were studied. The results showed that within 1000 ~ 1300℃, with the increase of temperature, although grain size increased, there was no obvious change on the phase composition of tantalum coating; the Ta crystals were polyhedral pyramid and increased with the temperature.

  20. Analyzing the performance of diamond-coated micro end mills.

    Energy Technology Data Exchange (ETDEWEB)

    Torres, C. D.; Heaney, P. J.; Sumant, A. V.; Hamilton, M. A.; Carpick, R. W.; Pfefferkorn, F. E.; Univ. of Wisconsin at Madison; Univ. of Pennsylvania

    2009-06-01

    A method is presented to improve the tool life and cutting performance of 300 {micro}m diameter tungsten carbide (WC) micro end mills by applying thin (<300 nm) fine-grained diamond (FGD) and nanocrystalline diamond (NCD) coatings using the hot-filament chemical vapor deposition (HF-CVD) process. The performance of the diamond-coated tools has been evaluated by comparing their performance in dry slot milling of 6061-T6 aluminum against uncoated WC micro end mills. Tool wear, coating integrity, and chip morphology were characterized using SEM and white light interferometry. The initial test results show a dramatic improvement in the tool integrity (i.e., corners not breaking off), a lower wear rate, no observable adhesion of aluminum to the diamond-coated tool, and a significant reduction in the cutting forces (>50%). Reduction of the cutting forces is attributed to the low friction and adhesion of the diamond coating. However, approximately 80% of the tools coated with the larger FGD coatings failed during testing due to delamination. Additional machining benefits were attained for the NCD films, which was obtained by using a higher nucleation density seeding process for diamond growth. This process allowed for thinner, smaller grained diamond coatings to be deposited on the micro end mills, and enabled continued operation of the tool even after the integrity of the diamond coating had been compromised. As opposed to the FGD-coated end mills, only 40% of the NCD-tools experienced delamination issues.

  1. Preparation of solar selective absorbing CuO coating for medium temperature application

    Institute of Scientific and Technical Information of China (English)

    HUANG Qunwu; WANG Yiping; LI Jinhua

    2007-01-01

    A new method of preparing CuO solar selective absorbing coating for medium temperature is presented.After pretreatment,brass was overlaid with CuO by chemical plating.The effects of reactant concentration,reaction temperature and reaction time on the absorptivity of CuO coating were investigated.The optimized condition of preparing CuO coating was obtained.The CuO coating was analyzed with X-ray photoelectron spectroscopy(XPS) and scanning electron microscopy(SEM).In order to prolong the period of use,the CuO coating was protected by TiO2.The experiment shows that the TiO2/CuO coating is more heat-resistant,acid-resistant,and wear resistant than CuO coating,without Iosing absorptivity markedly.The TiO2 coating can reduce emissivity and protect the CuO coating.

  2. Biocompatibility of Niobium Coatings

    OpenAIRE

    René Olivares-Navarrete; Jhon Jairo Olaya; Claudia Ramírez; Sandra Elizabeth Rodil

    2011-01-01

    Niobium coatings deposited by magnetron sputtering were evaluated as a possible surface modification for stainless steel (SS) substrates in biomedical implants. The Nb coatings were deposited on 15 mm diameter stainless steel substrates having an average surface roughness of 2 mm. To evaluate the biocompatibility of the coatings three different in vitro tests, using human alveolar bone derived cells, were performed: cellular adhesion, proliferation and viability. Stainles...

  3. Porous Organic Nanolayers for Coating of Solid-state Devices

    Directory of Open Access Journals (Sweden)

    Asghar Waseem

    2011-05-01

    Full Text Available Abstract Background Highly hydrophobic surfaces can have very low surface energy and such low surface energy biological interfaces can be obtained using fluorinated coatings on surfaces. Deposition of biocompatible organic films on solid-state surfaces is attained with techniques like plasma polymerization, biomineralization and chemical vapor deposition. All these require special equipment or harsh chemicals. This paper presents a simple vapor-phase approach to directly coat solid-state surfaces with biocompatible films without any harsh chemical or plasma treatment. Hydrophilic and hydrophobic monomers were used for reaction and deposition of nanolayer films. The monomers were characterized and showed a very consistent coating of 3D micropore structures. Results The coating showed nano-textured surface morphology which can aid cell growth and provide rich molecular functionalization. The surface properties of the obtained film were regulated by varying monomer concentrations, reaction time and the vacuum pressure in a simple reaction chamber. Films were characterized by contact angle analysis for surface energy and with profilometer to measure the thickness. Fourier Transform Infrared Spectroscopy (FTIR analysis revealed the chemical composition of the coated films. Variations in the FTIR results with respect to different concentrations of monomers showed the chemical composition of the resulting films. Conclusion The presented approach of vapor-phase coating of solid-state structures is important and applicable in many areas of bio-nano interface development. The exposure of coatings to the solutions of different pH showed the stability of the coatings in chemical surroundings. The organic nanocoating of films can be used in bio-implants and many medical devices.

  4. Superhard Nanocomposite Coatings

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The recent development in the field of nanocomposite coatings with good mechanical properties is critically reviewed in this paper. The design principle and materials selection for the nanocomposite coatings are introduced. Different methods for the preparation of superhard nanocomposite coatings are described with emphasis on the magnetron sputtering. Based on recent theoretical and experimental results regarding the appearance of superhardness in nanocomposite coating, lattice parameter changes, crystallite size, microstructure and morphology are reviewed in detail. Also emphasized are the mechanical properties (especially on hardness) and the ways by which the properties are derived.

  5. Oxide coating development

    Energy Technology Data Exchange (ETDEWEB)

    Stinton, D.P.

    1995-06-01

    Monolithic SiC heat exchangers and fiber-reinforced SiC-matrix composite heat exchangers and filters are susceptible to corrosion by alkali metals at elevated temperatures. Protective coatings are currently being developed to isolate the SiC materials from the corrodants. Unfortunately, these coatings typically crack and spall when applied to SiC substrates. The purpose of this task is to determine the feasibility of using a compliant material between the protective coating and the substrate. The low-modulus compliant layer could absorb stresses and eliminate cracking and spalling of the protective coatings.

  6. Optical characterization of anti reflective sol-gel coatings fabricated using dip coating method

    Science.gov (United States)

    Melninkaitis, A.; Juškevičius, K.; Maciulevičius, M.; Sirutkaitis, V.; Beganskienė, A.; Kazadojev, I.; Kareiva, A.; Perednis, D.

    2007-01-01

    In recent years, there has been a growing interest in further development of sol-gel method which can produce ceramics and glasses using chemical precursors at relative low-temperatures. The applications for sol-gel derived products are numerous. Department of General and Inorganic Chemistry with Laser Research Center of Vilnius University and Institute of Physics continues an ongoing research effort on the synthesis, deposition and characterization of porous solgel. Our target is highly optically resistant anti-reflective (AR) coatings for general optics and nonlinear optical crystals. In order to produce AR coatings a silica (SiO II) sol-gel has been dip coated on the set of fused silica substrates. The optical properties and structure of AR-coatings deposited from hydrolysed tetraethylorthosilicate (TEOS) sol were characterized in detail in this study. The influence of different parameters on the formation of colloidal silica antireflective coatings by dip-coating technique has been investigated. All samples were characterized performing, transmission electron microscopy, UV-visible spectroscopy, atomic force microscopy, ellipsometric, total scattering and laser-induced damage threshold measurements. Herewith we present our recent results on synthesis of sol-gel solvents, coating fabrication and characterization of their optical properties.

  7. Performance of Polyaniline-coated Short Carbon Fibers in Electromagnetic Shielding Coating

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Combined nitric acid oxidation method and polyaniline (PANI)-coated method were applied to modify the surface properties of short carbon fibers (SCF). The electrical and mechanical properties of acrylic coatings with 50 wt pct PANI-coated carbon fiber were investigated by using scanning electron microscope (SEM), UV-Vis spectrophotometer, four-probe method and the coaxial cable method. The results of the pH measurement and XPS (X-ray photoelectron spectroscopy) patterns showed that the oxygen functional groups, such as -OH and -COOH, were attached on the carbon fiber surfaces after oxidation treatment. The XPS analysis of PANl-coated oxidized SCF (PAOSCF) revealed that PANI may bond on the surface of oxidized SCF with chemical bonds. SEM images and surface roughness analyses showed that PANl-coated layer changed the surface morphology. Compared with SCF/acrylic coating, the surface resistivity of PAOSCF/acrylic coating decreased from17.1 to 5.3 Ω/sq and the shielding efficiency (SE) value increased from 1.54 to 23.3 dB.

  8. ASSESSMENT OF STRIPPABLE COATINGS FOR DEACTIVATION AND DECOMMISSIONING

    International Nuclear Information System (INIS)

    Strippable coatings are polymer mixtures, such as water-based organic polymers, that are applied to a surface by paintbrush, roller, or spray applicator. As the polymer reacts, it attracts, absorbs, and chemically binds the contaminants; then, during the curing process, it mechanically locks the contaminants into the polymer matrix. Incorporating fiber reinforcement (such as a cotton scrim) into the coating may enhance the strength of these coatings. Once the coating dries, it can be stripped manually from the surface, In the case of auto-release coatings, the mixture cracks, flakes, and is collected by vacuuming. The surface properties of these coatings may be modified by applying a thin top coat (e.g., polyvinyl alcohol), which may provide a smoother, less permeable surface that would become less severely contaminated. In such a duplex, the thicker basis layer provides the required mechanical properties (e.g., strength and abrasion resistance), while the top layer provides protection from contamination. Once the strippable coating is removed, the loose surface contamination is removed with the coating, producing a dry, hard, non-airborne waste product. The use of strippable coatings during D and D operations has proved a viable option. These coatings can be used in the following three functions: As a protective coating, when applied to an uncontaminated surface in an area where contamination is present, so that on its removal the surface remains uncontaminated; As a decontamination agent, when applied to a contaminated surface, so that on its removal a significant decontamination of loose particulate activity is achieved; and As a fixative or tie-down coating, when applied to a contaminated surface, so that any loose contamination is tied down, thus preventing the spread of contamination during subsequent handling

  9. ASSESSMENT OF STRIPPABLE COATINGS FOR DEACTIVATION AND DECOMMISSIONING

    Energy Technology Data Exchange (ETDEWEB)

    M.A. Ebadian, Ph.D.

    1999-01-01

    Strippable coatings are polymer mixtures, such as water-based organic polymers, that are applied to a surface by paintbrush, roller, or spray applicator. As the polymer reacts, it attracts, absorbs, and chemically binds the contaminants; then, during the curing process, it mechanically locks the contaminants into the polymer matrix. Incorporating fiber reinforcement (such as a cotton scrim) into the coating may enhance the strength of these coatings. Once the coating dries, it can be stripped manually from the surface, In the case of auto-release coatings, the mixture cracks, flakes, and is collected by vacuuming. The surface properties of these coatings may be modified by applying a thin top coat (e.g., polyvinyl alcohol), which may provide a smoother, less permeable surface that would become less severely contaminated. In such a duplex, the thicker basis layer provides the required mechanical properties (e.g., strength and abrasion resistance), while the top layer provides protection from contamination. Once the strippable coating is removed, the loose surface contamination is removed with the coating, producing a dry, hard, non-airborne waste product. The use of strippable coatings during D&D operations has proved a viable option. These coatings can be used in the following three functions: As a protective coating, when applied to an uncontaminated surface in an area where contamination is present, so that on its removal the surface remains uncontaminated; As a decontamination agent, when applied to a contaminated surface, so that on its removal a significant decontamination of loose particulate activity is achieved; and As a fixative or tie-down coating, when applied to a contaminated surface, so that any loose contamination is tied down, thus preventing the spread of contamination during subsequent handling.

  10. Innovations in coating technology.

    Science.gov (United States)

    Behzadi, Sharareh S; Toegel, Stefan; Viernstein, Helmut

    2008-01-01

    Despite representing one of the oldest pharmaceutical techniques, coating of dosage forms is still frequently used in pharmaceutical manufacturing. The aims of coating range from simply masking the taste or odour of drugs to the sophisticated controlling of site and rate of drug release. The high expectations for different coating technologies have required great efforts regarding the development of reproducible and controllable production processes. Basically, improvements in coating methods have focused on particle movement, spraying systems, and air and energy transport. Thereby, homogeneous distribution of coating material and increased drying efficiency should be accomplished in order to achieve high end product quality. Moreover, given the claim of the FDA to design the end product quality already during the manufacturing process (Quality by Design), the development of analytical methods for the analysis, management and control of coating processes has attracted special attention during recent years. The present review focuses on recent patents claiming improvements in pharmaceutical coating technology and intends to first familiarize the reader with the available procedures and to subsequently explain the application of different analytical tools. Aiming to structure this comprehensive field, coating technologies are primarily divided into pan and fluidized bed coating methods. Regarding pan coating procedures, pans rotating around inclined, horizontal and vertical axes are reviewed separately. On the other hand, fluidized bed technologies are subdivided into those involving fluidized and spouted beds. Then, continuous processing techniques and improvements in spraying systems are discussed in dedicated chapters. Finally, currently used analytical methods for the understanding and management of coating processes are reviewed in detail in the last section of the review. PMID:19075909

  11. The development of CVR coatings for PBR fuels

    Science.gov (United States)

    Barletta, R. E.; Vanier, P. E.; Dowell, M. B.; Lennartz, J. A.

    Particle bed reactors (PBR's) are being developed for both space power and propulsion applications. These reactors operate with exhaust gas temperatures of 2500 to 3000 K and fuel temperatures hundreds of degrees higher. One fuel design for these reactors consists of uranium carbide encapsulated in either carbon or graphite. This fuel kernel must be protected from the coolant gas, usually H2, both to prevent attack of the kernel and to limit fission product release. Refractory carbide coatings have been proposed for this purpose. The typical coating process used for this is a chemical vapor deposition. Testing of other components have indicated the superiority of refractory carbide coatings applied using a chemical vapor reaction (CVR) process, however technology to apply these coatings to large numbers of fuel particles with diameters on the order of 500 pm were not readily available. A process to deposit these CVR coatings on surrogate fuel consisting of graphite particles is described. Several types of coatings have been applied to the graphite substrate: NbC in various thicknesses and a bilayer coating consisting of NbC and TaC with a intermediate layer of pyrolytic graphite. These coated particles have been characterized prior to test; results are presented.

  12. Aluminide Coatings for Power-Generation Applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y

    2003-11-17

    Aluminide coatings are of interest for many high temperature applications because of the possibility of improving the oxidation of structural alloys by forming a protective external alumina scale. In order to develop a comprehensive lifetime evaluation approach for aluminide coatings used in fossil energy systems, some of the important issues have been addressed in this report for aluminide coatings on Fe-based alloys (Task I) and on Ni-based alloys (Task II). In Task I, the oxidation behavior of iron aluminide coatings synthesized by chemical vapor deposition (CVD) was studied in air + 10vol.% H{sub 2}O in the temperature range of 700-800 C and the interdiffusion behavior between the coating and substrate was investigated in air at 500-800 C. Commercial ferritic (Fe-9Cr-1Mo) and type 304L (Fe-18Cr-9Ni, nominally) austenitic stainless steels were used as the substrates. For the oxidation study, the as-deposited coating consisted of a thin (<5 {micro}m), Al-rich outer layer above a thicker (30-50 {micro}m), lower Al inner layer. The specimens were cycled to 1000 1-h cycles at 700 C and 500 1-h cycles at 800 C, respectively. The CVD coating specimens showed excellent performance in the water vapor environment at both temperatures, while the uncoated alloys were severely attacked. These results suggest that an aluminide coating can substantially improve resistance to water vapor attack under these conditions. For the interdiffusion study, the ferritic and austenitic steels were coated with relatively thicker aluminide coatings consisting of a 20-25 {micro}m outer layer and a 150-250 {micro}m inner layer. The composition profiles before and after interdiffusion testing (up to 5,000h) were measured by electron probe microanalysis (EPMA). The decrease of the Al content at the coating surface was not significant after extended diffusion times ({le} 5,000h) at temperatures {le} 700 C. More interdiffusion occurred at 800 C in coatings on both Fe- 9Cr-1Mo and 304L alloys; a

  13. Molecular Adsorber Coating

    Science.gov (United States)

    Straka, Sharon; Peters, Wanda; Hasegawa, Mark; Hedgeland, Randy; Petro, John; Novo-Gradac, Kevin; Wong, Alfred; Triolo, Jack; Miller, Cory

    2011-01-01

    A document discusses a zeolite-based sprayable molecular adsorber coating that has been developed to alleviate the size and weight issues of current ceramic puck-based technology, while providing a configuration that more projects can use to protect against degradation from outgassed materials within a spacecraft, particularly contamination-sensitive instruments. This coating system demonstrates five times the adsorption capacity of previously developed adsorber coating slurries. The molecular adsorber formulation was developed and refined, and a procedure for spray application was developed. Samples were spray-coated and tested for capacity, thermal optical/radiative properties, coating adhesion, and thermal cycling. Work performed during this study indicates that the molecular adsorber formulation can be applied to aluminum, stainless steel, or other metal substrates that can accept silicate-based coatings. The coating can also function as a thermal- control coating. This adsorber will dramatically reduce the mass and volume restrictions, and is less expensive than the currently used molecular adsorber puck design.

  14. Rock-hard coatings

    NARCIS (Netherlands)

    Muller, M.

    2007-01-01

    Aircraft jet engines have to be able to withstand infernal conditions. Extreme heat and bitter cold tax coatings to the limit. Materials expert Dr Ir. Wim Sloof fits atoms together to develop rock-hard coatings. The latest invention in this field is known as ceramic matrix composites. Sloof has sign

  15. Coating of graphene

    NARCIS (Netherlands)

    Schneider, G.F.; Dekker, C.

    2014-01-01

    The present invention is in the field of highly crystalline graphene and coating said graphene with a layer. Said graphene may have further structures, such as nanopores, nanogaps, and nanoribbons. The coated graphene can be used for biomolecular analysis and modification, such as DNA-sequencing, as

  16. Fast-drying coating

    Science.gov (United States)

    Bartoszek, E. J.

    1978-01-01

    Nontoxic coating has excellent optical properties and can be pigmented in many different colors. It bonds well, can be applied by conventional methods, weathers well, and is self-extinguishing. Coating composition comprises latex blends of fluorocarbons, acrylic resins, stabilizers, modifiers, variety of inorganic pigments, and other additives. Suitable latex primers have also been developed from acrylic latex base.

  17. Methods of Antimicrobial Coating of Diverse Materials

    Science.gov (United States)

    Akse, James R.; Holtsnider, John T.; Kliestik, Helen

    2011-01-01

    Methods of coating diverse substrate materials with antimicrobial agents have been developed. Originally intended to reduce health risks to astronauts posed by pathogenic microorganisms that can grow on surfaces in spacecraft, these methods could also be used on Earth for example, to ensure sterility of surgical inserts and other medical equipment. The methods involve, generally, chemical preparation of substrate surfaces to enable attachment of antimicrobial molecules to the substrate surfaces via covalent bonds. Substrate materials that have been treated successfully include aluminum, glass, a corrosion-resistant nickel alloy, stainless steel, titanium, and poly(tetrafluoroethylene). Antimicrobial agents that have been successfully immobilized include antibiotics, enzymes, bacteriocins, bactericides, and fungicides. A variety of linkage chem istries were employed. Activity of antimicrobial coatings against gram-positive bacteria, gram-negative bacteria, and fungi was demonstrated. Results of investigations indicate that the most suitable combination of antimicrobial agent, substrate, and coating method depends upon the intended application.

  18. Catalytic thermal barrier coatings

    Science.gov (United States)

    Kulkarni, Anand A.; Campbell, Christian X.; Subramanian, Ramesh

    2009-06-02

    A catalyst element (30) for high temperature applications such as a gas turbine engine. The catalyst element includes a metal substrate such as a tube (32) having a layer of ceramic thermal barrier coating material (34) disposed on the substrate for thermally insulating the metal substrate from a high temperature fuel/air mixture. The ceramic thermal barrier coating material is formed of a crystal structure populated with base elements but with selected sites of the crystal structure being populated by substitute ions selected to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a higher rate than would the base compound without the ionic substitutions. Precious metal crystallites may be disposed within the crystal structure to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a lower light-off temperature than would the ceramic thermal barrier coating material without the precious metal crystallites.

  19. Charged-particle coating

    International Nuclear Information System (INIS)

    Advanced target designs require thicker (approx. 300 μm) coatings and better surface finishes that can be produced with current coating techniques. An advanced coating technique is proposed to provide maximum control of the coating flux and optimum manipulation of the shell during processing. In this scheme a small beam of ions or particles of known incident energy are collided with a levitated spherical mandrel. Precise control of the incident energy and angle of the deposition flux optimizes the control of the coating morphology while controlled rotation and noncontact support of the shell minimizes the possibility of particulate or damage generated defects. Almost infinite variability of the incident energy and material in this process provides increased flexibility of the target designs which can be physically realized

  20. Modern coating processes

    International Nuclear Information System (INIS)

    Articles collected in this volume explain both the present state of technique and current developments and problems in the environment of the following coating processes: - Hardfacing welding and soldering; - Thermal spraying; - Thin film technique (CVD, PVD); - Galvanising. Apart from basic representation of the conventional use of the different processes, both the new technological and material developments are to the fore. In this context, the purposeful post-treatment of coatings and the combination of different processes to achieve special coating properties should be mentioned. Examples of this show the hot isostatic pressing or laser melting of sprayed coatings, the simultaneous spraying and shot-blasting and the combination of galvanic and thin film techniques for the manufacture of hybrid systems. A further important group of subjects concerns the testing of various coatings. (orig.)

  1. Hybrid calcium phosphate coatings for implants

    Science.gov (United States)

    Malchikhina, Alena I.; Shesterikov, Evgeny V.; Bolbasov, Evgeny N.; Ignatov, Viktor P.; Tverdokhlebov, Sergei I.

    2016-08-01

    Monophasic biomaterials cannot provide all the necessary functions of bones or other calcined tissues. It is necessary to create for cancer patients the multiphase materials with the structure and composition simulating the natural bone. Such materials are classified as hybrid, obtained by a combination of chemically different components. The paper presents the physical, chemical and biological studies of coatings produced by hybrid technologies (HT), which combine primer layer and calcium phosphate (CaP) coating. The first HT type combines the method of vacuum arc titanium primer layer deposition on a stainless steel substrate with the following micro-arc oxidation (MAO) in phosphoric acid solution with addition of calcium compounds to achieve high supersaturated state. MAO CaP coatings feature high porosity (2-8%, pore size 5-7 µm) and surface morphology with the thickness greater than 5 µm. The thickness of Ti primer layer is 5-40 µm. Amorphous MAO CaP coating micro-hardness was measured at maximum normal load Fmax = 300 mN. It was 3.1 ± 0.8 GPa, surface layer elasticity modulus E = 110 ± 20 GPa, roughness Ra = 0.9 ± 0.1 µm, Rz = 7.5 ± 0.2 µm, which is less than the titanium primer layer roughness. Hybrid MAO CaP coating is biocompatible, able to form calcium phosphates from supersaturated body fluid (SBF) solution and also stimulates osteoinduction processes. The second HT type includes the oxide layer formation by thermal oxidation and then CaP target radio frequency magnetron sputtering (RFMS). Oxide-RFMS CaP coating is a thin dense coating with good adhesion to the substrate material, which can be used for metal implants. The RFMS CaP coating has thickness 1.6 ± 0.1 µm and consists of main target elements calcium and phosphorus and Ca/P ratio 2.4. The second HT type can form calcium phosphates from SBF solution. In vivo study shows that hybrid RFMS CaP coating is biocompatible and produces fibrointegration processes.

  2. Crop protection by seed coating.

    Science.gov (United States)

    Ehsanfar, S; Modarres-Sanavy, S A M

    2005-01-01

    Providence of sufficient and healthy food for increasing human population clears the importance of notice to increasing crop production in company with environmental loss reduction. Growth and yield of every plant with sexual reproduction, depends on germination & emergence of sown seeds. Seed is a small alive plant that its biological function is protection and nutrition of embryo. Biological, chemical and physiological characteristics of seed, affect on plant performance & its resistance to undesirable environmental conditions, and even on its total yield. So attention to seed and try to increase its performance is so important. One of the factors that cause reduction in germination percentage and seedling establishment, is seed disease. It's possible to control these diseases by treating the seed before planting it. Coating the seed with pesticides, is one of the ways to gain this goal. Seed coating is a technique in which several material as fertilizers, nutritional elements, moisture attractive or repulsive agents, plant growth regulators, rhizobium inocolum, chemical & pesticide etc, add to seed by adhesive agents and cause to increase seed performance and germination. Seed coating, leads to increase benefits in seed industry, because seeds can use all of their genetic vigor. This technique is used for seeds of many garden plants, valuable crops (such as corn, sunflower, canola, alfalfa,...) and some of the grasses. In this technique that was first used in coating cereal seeds in 1930, a thin and permeable layer of pesticide is stuck on seed surface and prevent damage of seedborn pathogens. This layer is melted or splited after absorption of moisture and suitable temperature by seed, and let the radical to exit the seed. In this approach materials are used accurately with seed, evaporation & leakage of pesticide and also adverse effects of some pesticides on seeds are diminished, and these factors cause to increase the accuracy and performance of pesticide

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Shoji Hayashi

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

  5. Characterization and improvement of coatings protecting concrete against contamination

    International Nuclear Information System (INIS)

    A new type of coatings has been developped for the protection of concrete structures which simplifies the dismantling of nuclear power reactors and decreases the risks of getting a huge volume of wastes. These coatings are decontaminable, resistant, adherent and, if necessary, strippable. They usually consist of composite systems, in order to perfectly fulfill the often contradicting functions. This made difficult the development of such a material. Different tests have been performed on many systems using such a type of painting: decontamination test (standard NF T 30 901), artificial aging (standard NF T 30 049), peeling tests, chemical corrosion tests. Some of these coatings have been selected. Each of them is an example of a given configuration - one layer strippable coating, composite system, etc... Many other coatings although not reported, gave encouraging results. Although in apparent contradiction with the present subject, an other property of these removable coatings has been studied, namely the fixing of contamination. This could also give interesting results. A prototype of such a coating has been qualified. We also present here a device developed by the STMI company. This device would allow taking off the contaminated coatings in case of a problem with the normal removal. Using peeling coatings in the Nuclear Power Reactors in the CEE seems to be an interesting possibility for the future

  6. Protection and Reinforcement of Tooth Structures by Dental Coating Materials

    Directory of Open Access Journals (Sweden)

    Toru Nikaido

    2012-10-01

    Full Text Available It has been proposed that a resin coating can serve as a means to protect dental structure after preparation of the tooth for indirect restorations, sealing the exposed dentin. The resin coating is applied on the cut surfaces immediately after tooth preparation and before making an impression by assembling a dentin bonding system and a flowable composite. Resin coatings minimize pulp irritation and improve the bond strength between a resin cement and tooth when bonding the restoration to tooth. Recently, thin-film coating dental materials based on all-in-one adhesive technology were introduced for resin coating of indirect restorations. The thin coating materials are applied in a single clinical step and create a barrier-like film layer on the prepared dentin. The thin coatings play an important role in protecting the dentin from physical, chemical, and biological irritation. In addition, these thin-film coating materials reportedly prevent marginal leakage beneath inlays or crown restorations. In light of the many benefits provided by such a protective layer, these all-in-one adhesive materials may therefore also have the potential to cover exposed root dentin surfaces and prevent caries formation. In this paper, recent progress of the dental coating materials and their clinical applications are reviewed.

  7. Synthesis of a Novel High Solid Coating Used in Automobile

    Institute of Scientific and Technical Information of China (English)

    LIANG Lu; CHEN Hua-lin; LIANG Shou-tian; LIU Bai-ling

    2004-01-01

    High solid coating is one of the most important environmental friendly coatings, and has been obtained great attention since 70s' last century. For there are high volatile organic compounds(VOCs) in the conventional coatings, which cause both a serious pollution and consume of a plentiful of natural resource, such as petroleum. The development and production of high solid coatings is pressing target for all the countries, especially for China due to our heavy population and short of resources. Based on the requirement, a novel coating with high solid content has been developed in our lab. The solid content of the resin is 80%, compared to the 55% of conversional resin. This coating is characterized by its unique molecular architecture, it is a kind of hyper-branched polymer with uniform distribution of the reactive groups along the molecular backbone, which can react with other chemicals to form a cross-linking structure at high temperature.The coating has a lower viscosity and lower Tg corresponding to its branched structure( scheme 1).This coating has been applied in the automobile finishing. The experimental results indicated that the developed coating presented high performance properties in fastness, mar resistance, and hardness, it also reduced the baking temperature, resulting in a energy saving.

  8. Ultrathin high-temperature oxidation-resistant coatings of hexagonal boron nitride

    Science.gov (United States)

    Liu, Zheng; Gong, Yongji; Zhou, Wu; Ma, Lulu; Yu, Jingjiang; Idrobo, Juan Carlos; Jung, Jeil; MacDonald, Allan H.; Vajtai, Robert; Lou, Jun; Ajayan, Pulickel M.

    2013-10-01

    Hexagonal boron nitride is a two-dimensional layered material that can be stable at 1,500 °C in air and will not react with most chemicals. Here we demonstrate large-scale, ultrathin, oxidation-resistant coatings of high-quality hexagonal boron nitride layers with controlled thicknesses from double layers to bulk. We show that such ultrathin hexagonal boron nitride films are impervious to oxygen diffusion even at high temperatures and can serve as high-performance oxidation-resistant coatings for nickel up to 1,100 °C in oxidizing atmospheres. Furthermore, graphene layers coated with a few hexagonal boron nitride layers are also protected at similarly high temperatures. These hexagonal boron nitride atomic layer coatings, which can be synthesized via scalable chemical vapour deposition method down to only two layers, could be the thinnest coating ever shown to withstand such extreme environments and find applications as chemically stable high-temperature coatings.

  9. Superior corrosion resistance by niobium coating

    International Nuclear Information System (INIS)

    Niobium is a reactive metal which passivates spontaneously in many aggressive environments. Niobium metal also has favorable thermal and mechanical properties for use in the chemical process industries as process equipment or ancillary components which require high reliability and extensive service life. Niobium coatings can be used in applications where superior resistance against aqueous corrosion or erosion in hot-gases is needed. In this study the corrosion resistance of electrodeposited niobium on AISI 316 stainless steels in acid media has been studied. The structure and composition of niobium coatings are reviewed. The morphology, microstructure and defects were studied using a scanning electron microscope. In short term experiments the electrolyte was 30% H2SO4 at a temperature of 298 K and during long term measurements the electrolyte was 1 M H2SO4. Both Alternating Current (AC) and Direct Current (DC) electrochemical methods were used to characterize the corrosion behavior of base material and coating-base material system. Short term measurement procedure for coated samples consisted of four different measurements. Polarization resistance values measured by electrochemical impedance spectroscopy showed that the corrosion resistance of niobium coatings was related to the development of a passive layer on the niobium surface. The Long Cyclic Anodic Polarization curves showed that electrodeposited niobium coatings are capable of isolating the substrate material completely from the electrolyte. The Potentiostatic Exertion measurements showed that the corrosion resistance of electrodeposited niobium coatings was five orders of magnitude better than of the base material AISI 316 in 30 % H2SO2 electrolyte

  10. Self-healing coatings containing microcapsule

    Science.gov (United States)

    Zhao, Yang; Zhang, Wei; Liao, Le-ping; Wang, Si-jie; Li, Wu-jun

    2012-01-01

    Effectiveness of epoxy resin filled microcapsules was investigated for healing of cracks generated in coatings. Microcapsules were prepared by in situ polymerization of urea-formaldehyde resin to form shell over epoxy resin droplets. Characteristics of these capsules were studied by 3D measuring laser microscope, particle size analyzer, Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimeter (DSC) to investigate their surface morphology, size distribution, chemical structure and thermal stability, respectively. The results indicate that microcapsules containing epoxy resins can be synthesized successfully. The size is around 100 μm. The rough outer surface of microcapsule is composed of agglomerated urea-formaldehyde nanoparticles. The size and surface morphology of microcapsule can be controlled by selecting different processing parameters. The microcapsules basically exhibit good storage stability at room temperature, and they are chemically stable before the heating temperature is up to approximately 200 °C. The model system of self-healing coating consists of epoxy resin matrix, 10 wt% microencapsulated healing agent, 2 wt% catalyst solution. The self-healing function of this coating system is evaluated through self-healing testing of damaged and healed coated steel samples.

  11. Development of W coatings for fusion applications

    Energy Technology Data Exchange (ETDEWEB)

    Ruset, C., E-mail: ruset@infim.ro [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); National Institute for Laser, Plasma and Radiation Physics, Euratom-MEdC Association, Bucharest (Romania); Grigore, E. [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); National Institute for Laser, Plasma and Radiation Physics, Euratom-MEdC Association, Bucharest (Romania); Maier, H.; Neu, R.; Greuner, H.; Mayer, M. [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Max-Plank Institut fuer Plasma Physik, Euratom Association, 85748 Garching (Germany); Matthews, G. [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Culham Centre for Fusion Energy, Euratom Association, Abingdon (United Kingdom)

    2011-10-15

    The paper gives a short overview on tungsten (W) coatings deposited by various methods on carbon materials (carbon fibre composite - CFC and fine grain graphite - FGG). Vacuum Plasma Spray (VPS), Chemical Vapor Deposition (CVD) and Physical Vapor Deposition (PVD) techniques are analyzed in respect with the characteristics and performances of the W coatings. A particular attention is paid to the Combined Magnetron Sputtering and Ion Implantation (CMSII) technique, which was developed during the last 4 years from laboratory to industrial scale and it is successfully applied for W coating (10-15 {mu}m and 20-25 {mu}m) of more than 2500 tiles for the ITER-like Wall project at JET and ASDEX Upgrade. This technique involves simultaneously magnetron sputtering and high energy (tens of keV) ion implantation. Due to the ion bombardment a stress relief occurs within the coating enabling its growth without delamination to a relatively large thickness. In addition, in order to adjust the thermal expansion mismatch between CFC and W, a Mo interlayer of 2-3 {mu}m is currently used. Experimentally, W/Mo coatings with a thickness up to 50 {mu}m were produced and successfully tested in the GLADIS ion beam facility up to 23 MW/m{sup 2}.

  12. Effect of Coating Surface Finishing on Fatigue Behavior of C450 Steel CAPVD Coated with (Ti,Cr)N

    Science.gov (United States)

    Poursaiedi, E.; Salarvand, A.

    2016-06-01

    The present study evaluated the effect of the surface quality of a custom 450 stainless steel substrate coated with a (Ti,Cr)N nanolayer by cathodic arc physical vapor deposition on fatigue performance in air and in a 3.5% NaCl solution. Scanning electron microscopy was used to locate crack origin sites and characterize the coating. X-ray diffraction was used to analyze the phase formation and measurement of residual stress in the coating. The results showed that the determined in plane residual stress is compressive, with amount of - 2.8 ± 0.4 GPa. Chemical mechanical polishing was used to decrease the coating surface roughness (R a from 0.35 to 0.07 µm). This significantly decreased the area having a high stress concentration and delayed the appearance of micro-cracks in the coating during fatigue testing. The results showed that when the material is tested under axial loading at a maximum alternating stress of 555 to 930 MPa, the fatigue strength of coated specimens with polished surfaces increased 10.6% in air and 26.7% in NaCl solution over the coated specimens with normal surfaces. Post-treatment of the coating increased the fatigue strength 3.5% in air and 10.1% in NaCl solution over the uncoated specimens and the weakness of CAPVD coating was eliminated in the field of fatigue.

  13. Silicon oxynitride: A field emission suppression coating

    Science.gov (United States)

    Theodore, Nimel D.

    We have studied coatings deposited using our inductively-coupled RF plasma ion implantation and desposition system to suppress field emission from large, 3-D electrode structures used in high voltage applications, like those used by Thomas Jefferson National Accelerator Facility in their DC-field photoelectron gun. Currently time and labor-intensive hand-polishing procedures are used to minimize field emission from these structures. Previous work had shown that the field emission from polished stainless steel (27 muA of field-emitted current at 15 MV/m) could be drastically reduced with simultaneous deposition of sputtered silicon dioxide during nitrogen implantation (167 pA of field-emitted current at 30 MV/m). We have determined that this unique implantation and deposition procedure produces high-purity silicon oxynitride films that can suppress field emission from stainless steel regardless of their initial surface polish. However, when this implantation procedure was applied to large, 3-D substrates, arcs occurred, damaging the coating and causing unreliable and unrepeatable field emission suppression. We have developed a novel reactive sputtering procedure to deposit high-purity silicon oxynitride coatings without nitrogen ion implantation. We can control the stoichometry and deposition rate of these coatings by adjusting the nitrogen pressure and incident RF-power. Using profilometry, Auger electron spectroscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Rutherford backscattering spectrometry, elastic recoil detection analysis, and current-voltage measurements, we have determined that the elemental composition, chemical bonding, density, and electrical properties of the reactively-sputtered silicon oxynitride coatings are similar to those produced by nitrogen implantation during silicon dioxide deposition. Furthermore, high voltage tests determined that both coatings similarly suppress field emission from 6" diameter, polished

  14. Isomolybdate conversion coatings

    Science.gov (United States)

    Minevski, Zoran (Inventor); Maxey, Jason (Inventor); Nelson, Carl (Inventor); Eylem, Cahit (Inventor)

    2002-01-01

    A conversion coating solution and process forms a stable and corrosion-resistant layer on metal substrates or layers or, more preferably, on a boehmite layer or other base conversion coating. The conversion coating process involves contacting the substrate, layer or coating with an aqueous alkali metal isomolybdate solution in order to convert the surface of the substrate, layer or coating to a stable conversion coating. The aqueous alkali metal molybdates are selected from sodium molybdate (Na.sub.2 MoO.sub.4), lithium molybdate (Li.sub.2 MoO.sub.4), potassium molybdate (K.sub.2 MoO.sub.4), or combinations thereof, with the most preferred alkali metal molybdate being sodium molybdate. The concentration of alkali metal molybdates in the solution is preferably less than 5% by weight. In addition to the alkali metal molybdates, the conversion coating solution may include alkaline metal passivators selected from lithium nitrate (LiNO.sub.3), sodium nitrate (NaNO.sub.3), ammonia nitrate (NH.sub.4 NO.sub.3), and combinations thereof; lithium chloride, potassium hexafluorozirconate (K.sub.2 ZrF.sub.6) or potassium hexafluorotitanate (K.sub.2 TiF.sub.6).

  15. Fluorine Based Superhydrophobic Coatings

    Directory of Open Access Journals (Sweden)

    Jean-Denis Brassard

    2012-05-01

    Full Text Available Superhydrophobic coatings, inspired by nature, are an emerging technology. These water repellent coatings can be used as solutions for corrosion, biofouling and even water and air drag reduction applications. In this work, synthesis of monodispersive silica nanoparticles of ~120 nm diameter has been realized via Stöber process and further functionalized using fluoroalkylsilane (FAS-17 molecules to incorporate the fluorinated groups with the silica nanoparticles in an ethanolic solution. The synthesized fluorinated silica nanoparticles have been spin coated on flat aluminum alloy, silicon and glass substrates. Functionalization of silica nanoparticles with fluorinated groups has been confirmed by Fourier Transform Infrared spectroscopy (FTIR by showing the presence of C-F and Si-O-Si bonds. The water contact angles and surface roughness increase with the number of spin-coated thin films layers. The critical size of ~119 nm renders aluminum surface superhydrophobic with three layers of coating using as-prepared nanoparticle suspended solution. On the other hand, seven layers are required for a 50 vol.% diluted solution to achieve superhydrophobicity. In both the cases, water contact angles were more than 150°, contact angle hysteresis was less than 2° having a critical roughness value of ~0.700 µm. The fluorinated silica nanoparticle coated surfaces are also transparent and can be used as paint additives to obtain transparent coatings.

  16. PVD and CVD gradient coatings on sintered carbides and sialon tool ceramics

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2010-12-01

    Full Text Available Purpose: The main objective of the work is to investigate the structure and properties of multilayer gradient coatings produced in PVD and CVD processes on sintered carbides and on sialon ceramics, and to define the influence of the properties of the coatings such as microhardness, adhesion, thickness and size of grains on the applicable properties of cutting edges covered by such coatings.Design/methodology/approach: The investigation studies pertaining to the following have been carried out: the structures of the substrates and coatings with the application of transmission electron microscopy; the structure and topography of coating surfaces with the use of electron scanning microscopy; chemical composition of the coatings using the GDOES and EDS methods; phase composition of the coatings using X-ray diffraction and grazing incident X-ray diffraction technique (GIXRD; grain size of the investigated coatings using Scherrer’s method; properties of the coatings including thickness, microhardness, adhesion and roughness; properties of the operating coatings in cutting trials. The models of artificial neural networks have been worked out which involve the dependencies between the durability of the cutting edge and properties of the coatings.Findings: Good adhesion of the coatings to the substrate from sintered carbides is connected with the diffusive mixing of the components of the coating and substrate. In the case of PVD coatings obtained on sialon ceramics, the highest adhesion to the substrate (Lc=53-112 N has been demonstrated by the coatings containing the AlN phase of the hexagonal lattice having the same type of atomic (covalence bond in the coating as in the ceramic substrate. The damage mechanism of the investigated coatings depends to a high degree on their adhesion to the substrate. The durability of cutting edges covered by the investigated coatings depends principally on the adhesion of the coatings to the substrate, and to a lesser

  17. Chemical Emergencies

    Science.gov (United States)

    When a hazardous chemical has been released, it may harm people's health. Chemical releases can be unintentional, as in the case of an ... the case of a terrorist attack with a chemical weapon. Some hazardous chemicals have been developed by ...

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

    Science.gov (United States)

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

    2014-02-15

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

  19. Zirconium influence on microstructure of aluminide coatings deposited on nickel substrate by CVD method

    Indian Academy of Sciences (India)

    Jolanta Romanowska; Maryana Zagula-Yavorska; Jan Sieniawski

    2013-11-01

    Influence of Zr on the microstructure and phase characteristics of aluminide diffusion coatings deposited on the nickel substrate has been investigated in this study. The coatings with and without zirconium were deposited by CVD method. The cross-section chemical composition investigations revealed that during the coatings formation, there is an inward aluminum diffusion and outward nickel diffusion in both types of coatings (with and without zirconium), whereas zirconium is located far below the coating surface, at a depth of ∼17 m, between -NiAl phase and '-Ni3Al phase. XRD examinations showed that -NiAl, -NiAl and '-Ni3Al were the main components of the deposited coatings. -NiAl phase is on the surface of the coatings, whereas -NiAl and '-Ni3Al form deeper parts of the coatings. Zirconium is dissolved in NiAl on the border between -NiAl and '-Ni3Al.

  20. Microstructure and characterization of a novel cobalt coating prepared by cathode plasma electrolytic deposition

    Science.gov (United States)

    Quan, Cheng; He, Yedong

    2015-10-01

    A novel cobalt coating was prepared by cathode plasma electrolytic deposition (CPED). The kinetics of the electrode process in cathode plasma electrolytic deposition was studied. The composition and microstructure of the deposited coatings were investigated by SEM, EDS, XRD and TEM. The novel cobalt coatings were dense and uniform, showing a typically molten morphology, and were deposited with a rather fast rate. Different from the coatings prepared by conventional electrodeposition or chemical plating, pure cobalt coatings with face center cubic (fcc) structure were obtained by CPED. The deposited coatings were nanocrystalline structure with an average grain size of 40-50 nm, exhibited high hardness, excellent adhesion with the stainless steels, and superior wear resistance. The properties of the novel cobalt coatings prepared by CPED have been improved significantly, as compared with that prepared by conventional methods. It reveals that cathode plasma electrolytic deposition is an effective way to prepare novel cobalt coatings with high quality.

  1. Rapid Assessment of Tablet Film Coating Quality by Multispectral UV Imaging

    DEFF Research Database (Denmark)

    Klukkert, Marten; Wu, Jian X.; Rantanen, Jukka;

    2016-01-01

    coated with a polyvinyl alcohol-polyethylene glycol graft copolymer using a pan coater. It was demonstrated that the coating intactness can be assessed accurately and fast by UV imaging. The different types of coating defects could be differentiated and localized based on multivariate image analysis and......Chemical imaging techniques are beneficial for control of tablet coating layer quality as they provide spectral and spatial information and allow characterization of various types of coating defects. The purpose of this study was to assess the applicability of multispectral UV imaging for...... assessment of the coating layer quality of tablets. UV images were used to detect, characterize, and localize coating layer defects such as chipped parts, inhomogeneities, and cracks, as well as to evaluate the coating surface texture. Acetylsalicylic acid tablets were prepared on a rotary tablet press and...

  2. Friction and wear properties of diamonds and diamond coatings

    International Nuclear Information System (INIS)

    The recent development of chemical vapor deposition techniques for diamond growth enables bearings to be designed which exploit diamond's low friction and extreme resistance to wear. However, currently produced diamond coatings differ from natural diamond surfaces in that they are polycrystalline and faceted, and often contain appreciable amounts of non-diamond material (i.e. graphitic or amorphous carbon). Roughness, in particular, influences the friction and wear properties; rough coatings severely abrade softer materials, and can even wear natural diamond sliders. Nevertheless, the best available coatings exhibit friction coefficients as low as those of natural diamond and are highly resistant to wear. This paper reviews the tribological properties of natural diamond, and compares them with those of chemical vapor deposited diamond coatings. Emphasis is placed on the roles played by roughness and material transfer in controlling frictional behavior. (orig.)

  3. Decontamination of Belarus research reactor installation by strippable coatings

    International Nuclear Information System (INIS)

    The goal of this study was to develop new strippable coatings using water-based solutions of polyvinyl alcohol and active additives for decontamination of research reactor equipment. The employment of strippable coatings makes it possible to minimize the quantity of liquid radioactive waste. The selection of strippable decontaminating coatings was carried out on the basis of general requirements to decontaminating solutions: successfully dissolve corrosion deposits; ensure the desorption of radionuclides from the surfaces and the absence of resorption; introduce minimal corrosion effect of construction materials; to be relatively cheap and available in reagents. The decontaminating ability and adhesion properties of these coatings depending on metal and deposit sorts were investigated. Research on the chemical stability of solid wastes was carried out. The data obtained were the base for recommendations on waste management procedure for used films and pastes. A full-scale case-study analysis was performed for comparing strippable coatings with decontaminating solutions. (author)

  4. The coating layer structure of commercial chrome plates

    International Nuclear Information System (INIS)

    Highlights: • AES and XPS depth profiling analysis were used in the experiment. • The detailed coating layer structure of the commercial chrome plate was obtained. • Peak fitting method was used to investigate the chemical states of Cr in the coating. - Abstract: The surface and cross-sectional morphologies of the commercial chrome plate coating layer with the thickness of dozens of nanometers have been observed. To investigate the detailed structure of the coating layer, Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) combined with the low energy Ar+ sputtering technique have been employed. Through careful analysis of experimental data, it can be obtained that the coating layer of commercial chrome plates is composed of four layers from top to bottom with different compositions

  5. Preparation of stable ultrahydrophobic and superoleophobic silica-based coating.

    Science.gov (United States)

    Nimittrakoolchai, On-Uma; Supothina, Sitthisuntorn

    2012-06-01

    Silica-Based coatings having excellent water- and oil-repellent properties and good weathering stability have been deposited onto glass surface by a simple one-step dip coating technique. To achieve ultra water repellency and super oil repellency, the chemical composition of SiO2 nanoparticle employed as surface roughness enhancer and trichloro(1H,1H,2H,2H-perfluorooctyl)silane employed as surface-energy reducing substance was varied. At the optimum synthesis condition, the coating exhibited very high contact angles of 173.2, 146.7 and 147.6 degrees for water, ethylene glycol and seed oil, respectively. The achievement of excellent water- and oil-repellency is also described based on the presence of air trapped in micropore of the coating in addition to its high surface roughness and low surface free energy. The coatings have good weathering stability based on natural and accelerated weathering tests indicating feasibility for practical use.

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

    International Nuclear Information System (INIS)

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

  7. Comments on process of duplex coatings on aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    Samir H.A.; QIAN Han-cheng(钱翰城); XIA Bo-cai(夏伯才); WU Shi-ming(吴仕明)

    2004-01-01

    Despite the great achievements made in improvement of wear resistance properties of aluminum alloys,their applications in heavy surface load-bearing are limited. Single coating is insufficient to produce the desired combination of surface properties. These problems can be solved through the duplex coatings. The aim of the present study is to overview the research advances on processes of duplex coatings on aluminum alloys combined with micro plasma oxidation process and with other modern processes such as physical vapour deposition and plasma assisted chemical vapour deposition and also to evaluate the performance of micro plasma oxidation coatings in improving the load-bearing, friction and wear resistance properties of aluminum alloys in comparison with other coatings. Wherein, a more detailed presentation of the processes and their performances and disadvantages are given as well.

  8. Surface oxidation phenomena of boride coatings grown on iron

    International Nuclear Information System (INIS)

    Very hard boride coatings are grown on various metals using thermochemical as well as chemical vapour deposition techniques. In this way many surface properties, and in particular the wear resistance, can be considerably improved. Usually, also the corrosion behaviour of the treated components is important. In particular, oxidizing atmospheres are involved in many applications where, therefore, coating-environment interactions can play a relevant role. In a previous work, the early stages of the oxidation of iron borides were studied by treating single phase compacted powders in flowing oxygen at low temperatures (300-450deg C). In the present paper, the attention is addressed to the oxidation of both single phase and polyphase boride coatings thermochemically grown on iron. The single phase boride coatings were constituted by Fe2B, while the polyphase coatings were constituted by an inner Fe2B layer and an outer FeB-base layer. All the boride layers displayed strong (002) preferred crystallographic orientations. (orig.)

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

    Science.gov (United States)

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

    1988-06-29

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

  10. Simple Chemical Vapor Deposition Experiment

    Science.gov (United States)

    Pedersen, Henrik

    2014-01-01

    Chemical vapor deposition (CVD) is a process commonly used for the synthesis of thin films for several important technological applications, for example, microelectronics, hard coatings, and smart windows. Unfortunately, the complexity and prohibitive cost of CVD equipment makes it seldom available for undergraduate chemistry students. Here, a…

  11. Thermal shock behavior of platinum aluminide bond coat/electron beam-physical vapor deposited thermal barrier coatings

    International Nuclear Information System (INIS)

    Highlights: • TBCs of (Ni, Pt)Al bond coat with grit blasting process and YSZ ceramic coating. • Grain boundary ridges are the sites for spallation damage initiation in TBCs. • Ridges removed, cavities formation appeared and the damage initiation deteriorated. • Damage initiation and progression at interface lead to a buckling failure. - Abstract: Thermal barrier coating systems (TBCs) including of chemical vapor deposited (Ni, Pt)Al bond coat with grit blasting process and electron beam physical vapor deposited Y2O3-stabilized-ZrO2 (YSZ) ceramic coating were investigated. The phase structures, surface and cross-sectional morphologies, thermal shock behaviors and residual stresses of the coatings were studied in detail. Grain boundary ridges still remain on the surface of bond coat prior to the deposition of the ceramic coating, which are shown to be the major sites for spallation damage initiation in TBCs. When these ridges are mostly removed, they appear some of cavities formation and then the damage initiation mode is deteriorated. Damage initiation and progression occurs at the bond coat to thermally grown oxide (TGO) interface leading to a buckling failure behavior. A buckle failure once started may be arrested when it runs into a region of high bond coat to TGO interface toughness. Thus, complete failure requires further loss in toughness of the bond coat to TGO interface during cooling. The suppressed cavities formation, the removed ridges at the grain boundaries, the relative high TGO to bond coat interface toughness, the uniform growth behavior of TGO thickening and the lower of the residual stress are the primary factors for prolonging the lifetime of TBCs

  12. Thermal shock behavior of platinum aluminide bond coat/electron beam-physical vapor deposited thermal barrier coatings

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhenhua, E-mail: zhxuciac@163.com [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Dai, Jianwei [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Niu, Jing [Shenyang Liming Aero-engine (Group) Corporation Ltd., Institute of Metallurgical Technology, Technical Center, Shengyang 110043 (China); Li, Na; Huang, Guanghong; He, Limin [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China)

    2014-12-25

    Highlights: • TBCs of (Ni, Pt)Al bond coat with grit blasting process and YSZ ceramic coating. • Grain boundary ridges are the sites for spallation damage initiation in TBCs. • Ridges removed, cavities formation appeared and the damage initiation deteriorated. • Damage initiation and progression at interface lead to a buckling failure. - Abstract: Thermal barrier coating systems (TBCs) including of chemical vapor deposited (Ni, Pt)Al bond coat with grit blasting process and electron beam physical vapor deposited Y{sub 2}O{sub 3}-stabilized-ZrO{sub 2} (YSZ) ceramic coating were investigated. The phase structures, surface and cross-sectional morphologies, thermal shock behaviors and residual stresses of the coatings were studied in detail. Grain boundary ridges still remain on the surface of bond coat prior to the deposition of the ceramic coating, which are shown to be the major sites for spallation damage initiation in TBCs. When these ridges are mostly removed, they appear some of cavities formation and then the damage initiation mode is deteriorated. Damage initiation and progression occurs at the bond coat to thermally grown oxide (TGO) interface leading to a buckling failure behavior. A buckle failure once started may be arrested when it runs into a region of high bond coat to TGO interface toughness. Thus, complete failure requires further loss in toughness of the bond coat to TGO interface during cooling. The suppressed cavities formation, the removed ridges at the grain boundaries, the relative high TGO to bond coat interface toughness, the uniform growth behavior of TGO thickening and the lower of the residual stress are the primary factors for prolonging the lifetime of TBCs.

  13. 通过化学分析预测锌基涂层耐蚀性能的专家系统%Expert systems for prediction of corrosion properities of Zn-based coatings from the chemical analysis

    Institute of Scientific and Technical Information of China (English)

    BENGTSON Arne; HILDEBRAND Lars

    2012-01-01

    本研究旨在开发一种用于预测锌基涂层耐腐蚀性的通用方法,其可以表示为加速盐雾试验中的总质量损失.本方法仅基于三个分析参数,即锌、铝和镁的总涂层质量.这种限制的原因是这三种参数可能通过在线分析获得.然后,预测的耐腐蚀性被包括在一个过程/质量控制系统.加速腐蚀试验在布雷斯特的Swerea KIMAB IC(腐蚀研究所)以及比利时的冶金研究中心(CRM)进行.试验按照雷诺ECC1试验D172028/--C(12周)以及CRM研发的加速循环腐蚀试验进行.根据总质量损失情况,原材料被分为四个耐腐蚀级别.所有腐蚀试验都清晰、充分地说明了元素镁和铝的正面影响.对于涂层中大多数这些元素来说,元素镁和铝的影响比单独元素锌的影响大很多.因此,引入了一个新的量,叫做“等量元素锌涂层重量”.此量与锌、铝和镁的涂层重量线性相关.使用专家系统开发了一种用于预测耐腐蚀性的模型,此模型基于回归分析和“决策树”算法.根据上述提及的三个分析参数(即锌、铝和镁的总涂层质量),可以使用开发的模型准确对27种材料中的25种进行分类.总之,即使是在线状态,这种方法也有可能准确预测出腐蚀行为.出于材料研发的目的,还扩展了专家系统使其包括其他分析参数.%The purpose of the work is to develop a general method, to predict the corrosion resistance of Zn-based coatings, expressed as total mass loss in an accelerated salt spray test. The method is to be based on just three analytical parametersi the total coating weights of Zn, Al and Mg. The reason for this restriction is that determination of these three parameters is possible in on—line analysis. The predicted corrosion resistance could then be included in a process/quality control system. Accelerated corrosion tests have been carried out by Swerea KIMAB IC (Institut de Corrosion) in Brest, and CRM in Belgium. Test were

  14. Lightweight Protective Coatings For Titanium Alloys

    Science.gov (United States)

    Wiedemann, Karl E.; Taylor, Patrick J.; Clark, Ronald K.

    1992-01-01

    Lightweight coating developed to protect titanium and titanium aluminide alloys and titanium-matrix composite materials from attack by environment when used at high temperatures. Applied by sol-gel methods, and thickness less than 5 micrometers. Reaction-barrier and self-healing diffusion-barrier layers combine to protect titanium alloy against chemical attack by oxygen and nitrogen at high temperatures with very promising results. Can be extended to protection of other environmentally sensitive materials.

  15. Silicon Nitride Antireflection Coatings for Photovoltaic Cells

    Science.gov (United States)

    Johnson, C.; Wydeven, T.; Donohoe, K.

    1984-01-01

    Chemical-vapor deposition adapted to yield graded index of refraction. Silicon nitride deposited in layers, refractive index of which decreases with distance away from cell/coating interface. Changing index of refraction allows adjustment of spectral transmittance for wavelengths which cell is most effective at converting light to electric current. Average conversion efficiency of solar cells increased from 8.84 percent to 12.63 percent.

  16. ANALYSIS OF THE PROPERTIES OF NEW GROUPS OF COATINGS APPLIED IN HIGHLY LOADED MACHINE COMPONENTS

    OpenAIRE

    Kinga CHRONOWSKA; Marcin KOT; Łukasz MAJOR

    2014-01-01

    The paper presents an overview of new groups of tribological coatings with complex microstructure deposited by PVD (Physical Vapour Deposition) and CVD (Chemical Vapor Deposition) techniques. The results of microstructure studies (TEM), mechanical and tribological properties of nanocomposite coatings nc-Cr2C/a-C:H and multilayers 16x(Ti/TiN) were shown. The properties of these modern coatings are compared with the properties of two single coatings a-C:H and TiN. All coatings were deposited by...

  17. Research into Thermal Sprayed Coatings with Ultrasonic Methods

    Directory of Open Access Journals (Sweden)

    Justinas Gargasas

    2012-01-01

    Full Text Available Research on thermal sprayed coatings with ultrasonic methods is the main object of this thesis. Metal surface coating was applied to modify its mechanical and physical-chemical properties and resistance to external impact and improve aesthetics. Spraying was carried out by scanning the rotating sample of 30 cm/s speed. Surface microstructure, ultrasonic thickness, porosity, micro hardness and surface modulus tests performed. Conclusions were formulated.Article in Lithuanian

  18. Research into Thermal Sprayed Coatings with Ultrasonic Methods

    OpenAIRE

    Justinas Gargasas; Irmantas Gedzevičius; Saulius Nagurnas

    2012-01-01

    Research on thermal sprayed coatings with ultrasonic methods is the main object of this thesis. Metal surface coating was applied to modify its mechanical and physical-chemical properties and resistance to external impact and improve aesthetics. Spraying was carried out by scanning the rotating sample of 30 cm/s speed. Surface microstructure, ultrasonic thickness, porosity, micro hardness and surface modulus tests performed. Conclusions were formulated.Article in Lithuanian

  19. Effect of boron nitride coating on fiber-matrix interactions

    International Nuclear Information System (INIS)

    Coatings can modify fiber-matrix reactions and consequently interfacial bond strengths. Commercially available mullite, silicon carbide, and carbon fibers were coated with boron nitride via low pressure chemical vapor deposition and incorporated into a mullite matrix by hot-pressing. The influence of fiber-matrix interactions for uncoated fibers on fracture morphologies was studied. These observations are related to the measured values of interfacial shear strengths

  20. Effects of titanium coating on property of diamond

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The titanium film was coated on the surface of diamond crystal in order to improve the chemical properties of diamond and the effect of titanium coating on the property of diamond was discussed. The anti-impacting strength, the oxidization process and the soakage property between vitrified bond and diamond were investigated. It is found that, when the titanium film is coated on the surface of diamond crystal, the soakage angle between vitrified bond and diamond decreases from 39.5° to 34.5° at 993 K, and the oxidization degree on the surface of diamonds is lowered greatly.

  1. Oxidation-resistant interfacial coatings for continuous fiber ceramic composites

    Energy Technology Data Exchange (ETDEWEB)

    Stinton, D.P.; Besmann, T.M.; Bleier, A. [Oak Ridge National Lab., TN (United States); Shanmugham, S.; Liaw, P.K. [Univ. of Tennessee, Knoxville, TN (United States)

    1995-08-01

    Continuous fiber ceramic composites mechanical behavior are influenced by the bonding characteristics between the fiber and the matrix. Finite modeling studies suggest that a low-modulus interfacial coating material will be effective in reducing the residual thermal stresses that are generated upon cooling from processing temperatures. Nicalon{trademark}/SiC composites with carbon, alumina and mullite interfacial coatings were fabricated with the SiC matrix deposited using a forced-flow, thermal gradient chemical vapor infiltration process. Composites with mullite interfacial coatings exhibited considerable fiber pull-out even after oxidation and have potential as a composite system.

  2. TRISO coated fuel particles with enhanced SiC properties

    Science.gov (United States)

    López-Honorato, E.; Tan, J.; Meadows, P. J.; Marsh, G.; Xiao, P.

    2009-07-01

    The silicon carbide (SiC) layer used for the formation of TRISO coated fuel particles is normally produced at 1500-1650 °C via fluidized bed chemical vapor deposition from methyltrichlorosilane in a hydrogen environment. In this work, we show the deposition of SiC coatings with uniform grain size throughout the coating thickness, as opposed to standard coatings which have larger grain sizes in the outer sections of the coating. Furthermore, the use of argon as the fluidizing gas and propylene as a carbon precursor, in addition to hydrogen and methyltrichlorosilane, allowed the deposition of stoichiometric SiC coatings with refined microstructure at 1400 and 1300 °C. The deposition of SiC at lower deposition temperatures was also advantageous since the reduced heat treatment was not detrimental to the properties of the inner pyrolytic carbon which generally occurs when SiC is deposited at 1500 °C. The use of a chemical vapor deposition coater with four spouts allowed the deposition of uniform and spherical coatings.

  3. Coating possibilities for magnetic switches

    International Nuclear Information System (INIS)

    High average power magnetic pulse compression systems are now being considered for use in several applications such as the High Power Radiation Source (HiPoRS) project. Such systems will require high reliability magnetic switches (saturable inductors) that are very efficient and have long lifetimes. One of the weakest components in magnetic switches is their interlaminar insulation. Considerations related to dielectric breakdown, thermal management of compact designs, and economical approaches for achieving these needs must be addressed. Various dielectric insulation and coating materials have been applied to Metglas foil in an attempt to solve the complex technical and practical problems associated with large magnetic switch structures. This work reports various needs, studies, results, and proposals in selecting and evaluating continuous coating approaches for magnetic foil. Techniques such as electrophoretic polymer deposition and surface chemical oxidation are discussed. We also propose continuous photofabrication processes for applying dielectric ribs or spacers to the foil which permit circulation of dielectric liquids for cooling during repetitive operation. 10 refs., 8 figs., 11 tabs

  4. NANOCOMPOSITE COATINGS WITH ENHANCED HARDNESS

    Institute of Scientific and Technical Information of China (English)

    J. Musil

    2005-01-01

    The article reviews the present state of the art in the magnetron sputtering of hart and superhard nanocomposite coatings. It is shown that there are (1) two groups of hard and superhard nanocomposites: (i) nc-MN/hard phase and (ii) nc-MN/soft phase, (2) three possible origins of the enhanced hardness: (i) dislocation-dominated plastic deformation, (ii) cohesive forces between atoms and (iii) nanostructure of materials, and (3) huge differences in the microstructure of single- and two-phase films. A main attention is devoted to the formation of nanocrystalline and/or X-ray amorphous films. Such films are created in a vicinity of transitions between (i)crystalline and amorphous phases, (ii) two crystalline phases of different chemical composition or (iii) two different preferred orientations of grains of the sane material from which the coating is composed. The existence of the last transition makes it possible to explain the enhanced hardness in single-phase films. The thermal stability and oxidation resistance of hard nanocomposite films is also shortly discussed.

  5. Guide for specifications elaboration of organic coatings in nuclear industry. Guide pour l'elaboration des cahiers des charges des revetements organiques dans l'Industrie Nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    1992-07-01

    This guide is divided in three parts. The first part is devoted to the technical prescriptions of organic coatings (physical and mechanical properties, chemical, biological and fire resistances, repairs possibility, aging and elimination aptitude), and of particular coatings (soils coatings: wear and antistatic properties, peelable coatings: peeling properties, tightness coatings: leakage, permeability and crack resistance). The second part gives tables for coatings choices. The third part deals of materials choices, application technologies and quality organization. (A.B.). tabs.

  6. Inorganic Coatings Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The inorganic Coatings Lab provides expertise to Navy and Joint Service platforms acquisition IPTs to aid in materials and processing choices which balance up-front...

  7. Aluminum phosphate coatings

    Science.gov (United States)

    Sambasivan, Sankar; Steiner, Kimberly A.; Rangan, Krishnaswamy K.

    2007-12-25

    Aluminophosphate compounds and compositions as can be used for substrate or composite films and coating to provide or enhance, without limitation, planarization, anti-biofouling and/or anti-microbial properties.

  8. Friction surfaced Stellite6 coatings

    Energy Technology Data Exchange (ETDEWEB)

    Rao, K. Prasad; Damodaram, R. [Department of Metallurgical and Materials Engineering - Indian Institute of Technology Madras, Chennai 600 036 (India); Rafi, H. Khalid, E-mail: khalidrafi@gmail.com [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India); Ram, G.D. Janaki [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India); Reddy, G. Madhusudhan [Metal Joining Group, Defence Metallurgical Research Laboratory (DMRL) Kanchanbagh, Hyderabad 500 058 (India); Nagalakshmi, R. [Welding Research Institute, Bharat Heavy Electricals Limited, Tiruchirappalli 620 014 (India)

    2012-08-15

    Solid state Stellite6 coatings were deposited on steel substrate by friction surfacing and compared with Stellite6 cast rod and coatings deposited by gas tungsten arc and plasma transferred arc welding processes. Friction surfaced coatings exhibited finer and uniformly distributed carbides and were characterized by the absence of solidification structure and compositional homogeneity compared to cast rod, gas tungsten arc and plasma transferred coatings. Friction surfaced coating showed relatively higher hardness. X-ray diffraction of samples showed only face centered cubic Co peaks while cold worked coating showed hexagonally close packed Co also. - Highlights: Black-Right-Pointing-Pointer Stellite6 used as coating material for friction surfacing. Black-Right-Pointing-Pointer Friction surfaced (FS) coatings compared with casting, GTA and PTA processes. Black-Right-Pointing-Pointer Finer and uniformly distributed carbides in friction surfaced coatings. Black-Right-Pointing-Pointer Absence of melting results compositional homogeneity in FS Stellite6 coatings.

  9. Nanostructured Superhydrophobic Coatings

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-03-01

    This factsheet describes a research project that deals with the nanostructured superhydrophobic (SH) powders developed at ORNL. This project seeks to (1) improve powder quality; (2) identify binders for plastics, fiberglass, metal (steel being the first priority), wood, and other products such as rubber and shingles; (3) test the coated product for coating quality and durability under operating conditions; and (4) application testing and production of powders in quantity.

  10. Spin coating apparatus

    Science.gov (United States)

    Torczynski, John R.

    2000-01-01

    A spin coating apparatus requires less cleanroom air flow than prior spin coating apparatus to minimize cleanroom contamination. A shaped exhaust duct from the spin coater maintains process quality while requiring reduced cleanroom air flow. The exhaust duct can decrease in cross section as it extends from the wafer, minimizing eddy formation. The exhaust duct can conform to entrainment streamlines to minimize eddy formation and reduce interprocess contamination at minimal cleanroom air flow rates.

  11. Advanced coated particle fuels

    International Nuclear Information System (INIS)

    The coated particle fuel (cpf) has been developed for use in high-temperature gas-cooled reactors, but it may find applications in other types of reactors. In JAERI, besides the development of cpf for High Temperature Engineering Test Reactor, conceptual studies of the cpf applications in actinide burner reactors and space reactors have been made. The conceptual design studies as well as the research and development of advanced coatings, ZrC and TiN, are reviewed. (author)

  12. Biocompatibility of Niobium Coatings

    Directory of Open Access Journals (Sweden)

    René Olivares-Navarrete

    2011-09-01

    Full Text Available Niobium coatings deposited by magnetron sputtering were evaluated as a possible surface modification for stainless steel (SS substrates in biomedical implants. The Nb coatings were deposited on 15 mm diameter stainless steel substrates having an average surface roughness of 2 mm. To evaluate the biocompatibility of the coatings three different in vitro tests, using human alveolar bone derived cells, were performed: cellular adhesion, proliferation and viability. Stainless steel substrates and tissue culture plastic were also studied, in order to give comparative information. No toxic response was observed for any of the surfaces, indicating that the Nb coatings act as a biocompatible, bioinert material. Cell morphology was also studied by immune-fluorescence and the results confirmed the healthy state of the cells on the Nb surface. X-ray diffraction analysis of the coating shows that the film is polycrystalline with a body centered cubic structure. The surface composition and corrosion resistance of both the substrate and the Nb coating were also studied by X-ray photoelectron spectroscopy and potentiodynamic tests. Water contact angle measurements showed that the Nb surface is more hydrophobic than the SS substrate.

  13. Residual stresses within sprayed coatings

    Institute of Scientific and Technical Information of China (English)

    JIANG Yi; XU Bin-shi; WANG Hai-dou

    2005-01-01

    Some important developments of residual stress researches for coating-based systems were studied. The following topics were included the sources of residual stresses in coatings: error analysis of Stoney's equation in the curvature method used for the measurement of coating residual stress, the modeling of residual stress and some analytical models for predicting the residual stresses in coatings. These topics should provide some important insights for the fail-safe design of the coating-based systems.

  14. Hydroxyapatite coatings for biomedical applications

    CERN Document Server

    Zhang, Sam

    2013-01-01

    Hydroxyapatite coatings are of great importance in the biological and biomedical coatings fields, especially in the current era of nanotechnology and bioapplications. With a bonelike structure that promotes osseointegration, hydroxyapatite coating can be applied to otherwise bioinactive implants to make their surface bioactive, thus achieving faster healing and recovery. In addition to applications in orthopedic and dental implants, this coating can also be used in drug delivery. Hydroxyapatite Coatings for Biomedical Applications explores developments in the processing and property characteri

  15. Interaction phenomena between ceramic coatings and liquid uranium alloys

    International Nuclear Information System (INIS)

    Owing to the high chemical reactivity of molten uranium alloys, the use of traditional graphite crucibles for casting fuel slugs for a sodium-cooled fast reactor (SFR) is problematic. Moreover, rare earth (RE) elements retained in the fuel slugs for an SFR, which are extracted from the spent fuel by pyro-processing, are more reactive than uranium melt. Therefore, in this study, Y2O3 single-layer coatings with thicknesses of approximately 50, 70, and 120 μm and double-layer coatings of TaC/Y2O3 and Y2O3/TaC were plasma-sprayed onto niobium substrates and tested for thermal shock resistance and compatibility against U-10 wt% Zr and U-10 wt% Zr-5 wt% RE melt. The Y2O3 single-layer coating, regardless of coating thickness, and the TaC/Y2O3 double-layer coating showed good contact at the interface between the coating and the niobium substrate, with no deterioration after the thermal cycling test. In the interaction studies, the single- and double-layer coatings showed good compatibility with the U-Zr melt. However, the Y2O3 coatings with thicknesses of approximately 50 and 70 μm showed severe penetration of the U-Zr-RE melt and reacted with the niobium substrate. The single-layer Y2O3 coating with a thickness of 120 μm and the double-layer TaC/Y2O3 coating exhibited the most promising performance among the candidate coatings. (author)

  16. Transport and antifouling properties of papain-based antifouling coatings

    Science.gov (United States)

    Peres, Rafael S.; Armelin, Elaine; Moreno-Martínez, Juan A.; Alemán, Carlos; Ferreira, Carlos A.

    2015-06-01

    The aim of this work is to study the antifouling performance and water uptake behaviour of coatings formulated with papain (an environmentally friendly pigment). Antifouling coatings have been formulated using rosin (natural resin) as matrix and papain adsorbed in activated carbon as pigment. Electrochemical impedance spectroscopy (EIS) measurements were used to evaluate the behaviour of the formulated coatings in the marine environment and to calculate the apparent water coefficient of diffusion (D). FTIR and XPS analyses confirm the presence of papain adsorbed inside the activated carbon pores and the release of papain in water. Immersion tests in the Mediterranean Sea were carried out for 7 months to verify the degree of biofouling of the tested coatings. These field assays clearly indicate the excellent behaviour of papain-based antifouling coatings; the results being similar to those achieved using a commercial coating. Additionally, the EIS technique is shown to be a great tool to predict the coating diffusivity of antifouling coatings before immersion tests. Furthermore, the use of biodegradable papain as a nature-friendly antifouling agent can eliminate the negative environmental impact caused by metals and chemical biocides typically used in current commercial formulations.

  17. Electrophoretic deposition of zinc-substituted hydroxyapatite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Guangfei [Advanced Biomaterials and Tissue Engineering Center, Huazhong University of Science and Technology, Wuhan 430074 (China); Ma, Jun, E-mail: caltary@gmail.com [Advanced Biomaterials and Tissue Engineering Center, Huazhong University of Science and Technology, Wuhan 430074 (China); Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhang, Shengmin [Advanced Biomaterials and Tissue Engineering Center, Huazhong University of Science and Technology, Wuhan 430074 (China); Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-06-01

    Zinc-substituted hydroxyapatite nanoparticles synthesized by the co-precipitation method were used to coat stainless steel plates by electrophoretic deposition in n-butanol with triethanolamine as a dispersant. The effect of zinc concentration in the synthesis on the morphology and microstructure of coatings was investigated. It is found that the deposition current densities significantly increase with the increasing zinc concentration. The zinc-substituted hydroxyapatite coatings were analyzed by X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. It is inferred that hydroxyapatite and triethanolamine predominate in the chemical composition of coatings. With the increasing Zn/Ca ratios, the contents of triethanolamine decrease in the final products. The triethanolamine can be burnt out by heat treatment. The tests of adhesive strength have confirmed good adhesion between the coatings and substrates. The formation of new apatite layer on the coatings has been observed after 7 days of immersion in a simulated body fluid. In summary, the results show that dense, uniform zinc-substituted hydroxyapatite coatings are obtained by electrophoretic deposition when the Zn/Ca ratio reaches 5%. - Highlights: • We investigate the Zn/Ca ratios for the synthesis of zinc-substituted HA. • Zinc-substituted HA nanoparticles are used for electrophoretic deposition. • Adding triethanolamine and HCl may aid electrophoretic deposition. • Uniform dense coatings of zinc-substituted HA are obtained when Zn/Ca = 5%.

  18. Influence of octacalcium phosphate coating on osteoinductive properties of biomaterials.

    Science.gov (United States)

    Habibovic, P; van der Valk, C M; van Blitterswijk, C A; De Groot, K; Meijer, G

    2004-04-01

    In this study, we investigated the influence of octacalcium phosphate (OCP) coating on osteoinductive behaviour of the biomaterials. Porous titanium alloy (Ti6Al4V), hydroxyapatite (HA), biphasic calcium phosphate (BCP) and polyethylene glyco terephtalate/polybuthylene terephtalate (PEGT-PBT) copolymer, all uncoated and coated with biomimetically produced OCP, were implanted in back muscles of 10 goats for 6 and 12 weeks. Uncoated Ti6Al4Vand HA did not show any bone formation after intramuscular implantation. All OCP coated implants, except PEGT-PBT, did induce bone in the soft tissue. The reason for the non-inductive behaviour of the copolymer is probably its softness, that makes it impossible to maintain its porous shape after implantation. Both uncoated and OCP coated BCP induced bone. However, the amount of animals in which the bone was induced was higher in the coated BCP implants in comparison to the uncoated ones. Osteoinductive potential of biomaterials is influenced by various material characteristics, such as chemical composition, crystallinity, macro- and microstructure. OCP coating has a positive effect on osteoinductivity of the biomaterials. The combination of the advantages of biomimetic coating method above traditional methods, and a good osteoinductivity of OCP coating that is produced by using this method, opens new possibilities for designing more advanced orthopaedic implants. PMID:15332602

  19. Making silica rock coatings in the lab: synthetic desert varnish

    Science.gov (United States)

    Perry, Randall S.; Kolb, Vera M.; Philip, Ajish I.; Lynne, Bridget Y.; McLoughlin, Nicola; Sephton, Mark; Wacey, David; Green, Owen R.

    2005-09-01

    Desert varnish and silica rock coatings have perplexed investigators since Humboldt and Darwin. They are found in arid regions and deserts on Earth but the mechanism of their formation remains challenging (see Perry et al. this volume). One method of researching this is to investigate natural coatings, but another way is to attempt to produce coatings in vitro. Sugars, amino acids, and silicic acid, as well as other organic and (bio)organic compounds add to the complexity of naturally forming rock coatings. In the lab we reduced the complexity of the natural components and produced hard, silica coatings on basaltic chips obtained from the Mojave Desert. Sodium silicate solution was poured over the rocks and continuously exposed to heat and/or UV light. Upon evaporation the solutions were replenished. Experiments were performed at various pH's. The micro-deposits formed were analyzed using optical, SEM-EDAX, and electron microprobe. The coatings formed are similar in hardness and composition to silica glazes found on basalts in Hawaii as well as natural desert varnish found in US southwest deserts. Thermodynamic mechanisms are presented showing the theoretical mechanisms for overcoming energy barriers that allow amorphous silica to condense into hard coatings. This is the first time synthetic silica glazes that resemble natural coatings in hardness and chemical composition have been successfully reproduced in the laboratory, and helps to support an inorganic mechanism of formation of desert varnish as well as manganese-deficient silica glazes.

  20. Preparation of Conductive Coating Solutions by Blending Waterborne Acrylic Polyurethane Dispersion with Carbon Nanotube

    International Nuclear Information System (INIS)

    Waterborne polyurethane dispersion (WPUD) was synthesized from polycarbonate diol (PCD), isophorone diisocyanate (IPDI) and dimethylol propionic acid (DMPA) as starting materials. Then, waterborne acrylic polyurethane dispersion (AUD) was synthesized by reacting the WPUD with an acrylate monomer, methyl methacrylate (MMA). Subsequently, the AUD was mixed with multi-walled carbon nanotube (MWCNT) to yield a conductive coating solution, and the mixture was coated on the polycarbonate substrate. With increasing the amount of MMA in the AUD, the pencil hardness, abrasion resistance and chemical resistance of the coating films were improved, but the electrical conductivity of the coating films was decreased. On the other hand, the pencil hardness, abrasion resistance and chemical resistance of coating films were decreased, but the electrical conductivity was enhanced with increasing the amount of MWCNT in the conductive coating solutions

  1. Improving nanocrystalline diamond coatings for micro end mills

    Science.gov (United States)

    Heaney, Patrick J.

    A new method is presented for coating 300 mum diameter tungsten carbide (WC) micro end mills with diamond using a hot filament chemical vapor deposition (HF-CVD) method. This method has been developed to create uniform, conformal and continuous diamond coatings. Initial work is shown to prove the feasibility and concept of the project. This was the first work known to coat and evaluate the machining performance WC micro end mills. The performance of uncoated and coated micro end mills was evaluated by dry machining channels in 6061-T6 aluminum. The test results showed a 75% and 90% decrease in both cutting and trust forces for machining, respectfully. The coated tools produced a more predictable surface finish with no burring. These improved results are due to the superior tribological properties of diamond against aluminum. Initial results indicated severe problems with coating delamination causing complete tool failure. After proving the initial concept, new methods for optimizing the coating and improving performance were studied. Each optimization step is monitored through surface analysis techniques to monitor changes in coating morphology and diamond quality. Nucleation density was increased by improving the seed method, using ultra dispersed diamond (UDD) seed. The increase in nucleation density allowed the synthesis of coatings as thin as 60 nm. The adhesion of the coating to the tool was improved through carbon ion implantation (CII). CII is a different surface preparation technique that deactivates the effect of Co, while not weakening the tool. CII also creates a great nucleation layer which diamond can directly grow from, allowing the diamond coating to chemically bond to the substrate improving adhesion and eliminating the need for a seed layer. These thin coatings were shown to be of high quality sp3 trigonaly bonded diamond that resulted in lower machining forces with less delamination. The 90% reduction in machining forces that thin conformal

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

    Science.gov (United States)

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

    2012-06-01

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

  3. Cr-Ni ALLOY ELECTRODEPOSITION AND COMPARISON WITH CONVENTIONAL PURE Cr COATING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    M. Moniruzzaman

    2012-12-01

    Full Text Available Cr coating is widely used as the outer surface of precision parts due to its attractive appearance and superior corrosion resistance properties. It is obtained by electrodeposition via a conventional bath with hexavalent Cr ions. This manufacturing technique has many drawbacks, such as very low efficiency and high operating temperature and it is hazardous to health. In this work, we studied a Cr-Ni alloy deposition technique and compared the alloy coating properties to those with conventional Cr coating. Sequential two-step alloy electrodeposition was also compared. We took varying concentrations of Cr, Ni and complexing agents for the electrodeposition of Cr-Ni alloy and sequential Cr-Ni alloy coating on mild steel. Operating parameters, i.e. current density and temperature, were varied to examine their effects on the coating properties. The coatings thus obtained were characterized by visual observation, corrosion test, microhardness measurement, morphology and chemical analysis. The Cr-Ni alloy coating was found to be more corrosion resistant in 5% NaCl solution and harder than the pure Cr coating obtained by conventional electrodeposition. Toxic gas was produced in a much lower extent in the alloy coating than the conventional Cr coating technique. Again, the two-step Cr-Ni alloy coating was found better in terms of corrosion resistance as well as hardness compared to the Cr-Ni alloy coating. The process was also found to be much more environmentally friendly.

  4. Development of diamond coated tool and its performance in machining Al–11%Si alloy

    Indian Academy of Sciences (India)

    B Sahoo; A K Chattopadhyay; A B Chattopadhyay

    2002-11-01

    An attempt has been made to deposit CVD diamond coating on conventional carbide tool using hot filament CVD process. ISO grade K10 turning inserts with SPGN 120308 geometry were used to deposit diamond coating. This diamond coating well covering the rake surface, cutting edges and flank surfaces could be successfully deposited. The coatings were characterized by SEM, XRD and Raman spectroscopy for coating quality, morphology etc. Performance of diamond coated tool relative to that of uncoated carbide tool was evaluated in turning Al–11%Si alloy under dry environment. The diamond coated tool outperformed the uncoated carbide tool which severely suffered from sizeable built-up edge formation leading not only to escalation of cutting forces but also poorer surface finish. In contrast, the diamond coated tool, owing to chemical inertness of diamond coating towards the work material, did not show any trace of edge built-up even in dry environment and could maintain low level of cutting forces and remarkably improved surface finish. It has been further revealed that success of the diamond coated tool depends primarily on adhesion of the diamond coating with the carbide substrate and this is strongly influenced by the pre-treatment of the carbide substrate surface before coating.

  5. The influence of laser remelting on the structure and properties of Fe-Al coatings

    International Nuclear Information System (INIS)

    An evaluation of microstructure morphology of gas detonation sprayed coating obtained with Fe-Al type powders sprayed over a 45 type steel substrate was presented in this paper. These coatings were remelted using the laser beam. Influence of the laser beam on microstructure morphology and distribution of microhardness has been described. It has been found, that the laser remelting diminished porosity and lad to homogeneity of chemical content in the Fe-Al coating. (author)

  6. SHS Flame Spraying TiC-TiB2 Multiphase Coatings

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-jiang; DU Xin-kang; LU Da-qin; YE Ming-hui; ZHANG Long

    2004-01-01

    Utilizing SHS Reactive Flame Spraying (RFS) technology, TiC-TiB2-Al2O3 multiphase ceramics coatings were produced on steel substrate. Phase constituents and microstructure of the ceramic coatings were analyzed. The procedure of chemical combustion and structure transformation, reactive mechanism, and solidifying behavior during spaying were emphasized. Reactants which influenced on SHS spraying was discussed. SHS reactive spraying processes were studied.Mechanical properties of the coatings were tested.

  7. SHS Flame Spraying TiC-TiB2 Multiphase Coatings

    Institute of Scientific and Technical Information of China (English)

    WANGJian-jiang; DUXin-kang; LUDa-qin; YEMing-hui; ZHANGLong

    2004-01-01

    Utilizing SHS Reactive Flame Spraying (RFS) technology, TiC-TiB2-Al2O3 multiphase ceramics coatings were produced on steel substrate. Phase constituents and microstructure of the ceramic coatings were analyzed. The procedure of chemical combustion and structure transformation, reactive mechanism, and solidifying behavior during spaying were emphasized. Reactants which influenced on SHS spr-aying was discussed. SHS reactive spraying processes were studied, Mechanical properties of the coatings were tested.

  8. The shaping of zinc coating on surface steels and ductile iron casting

    OpenAIRE

    D. Kopyciński

    2010-01-01

    The studies aimed at an analysis of the formation and growth kinetics of zinc coating on reactive silicon-killed steels in a zinc bath. The growth kinetics of the produced zinc coatings was evaluated basing on the power-law growth equation. As regards galvanizing of the surface of products, investigation was done for various steel grades and ductile iron (DI) taking into account the quality and thickness of coating. It has been proved that the chemical constitution of basis significantly infl...

  9. Effects of different material coatings on the wearing of plowshares in soil tillage

    OpenAIRE

    Nalbant, Muammer; PALALI, A. Tufan

    2011-01-01

    The wearing behavior of coated layers on plowshares used in soil tillage was investigated. Plowshares produced from DIN EN 10 083 (30 MnB5) steel, widely used in plows, were coated with 20 mm hard chromium by electrolysis method, 20 mm electro-less nickel by chemical treatments, and 4 mm titaniumnitride (TiN) by physical vapor deposition to increase wearing resistance. The coated plowshare specimens, together with uncoated plowshare specimens, were mounted on test equipment to analyze their w...

  10. Oxidation behaviour of zirconium-doped NiAl coatings deposited on pure nickel

    OpenAIRE

    M. Zagula-Yavorska; J. Sieniawski; J. Romanowska

    2012-01-01

    Purpose: In this paper the oxidation behaviour of zirconium-doped NiAl coatings deposited on a pure nickel was investigated.Design/methodology/approach: The zirconium-doped NiAl coatings were deposited by the chemical vapour deposition method on the pure nickel. The microstructure investigations of zirconiumdoped aluminide coatings were performed by the use of an optical microscope (Nikon Epiphot 300) and a scanning electron microscope (Hitachi S-3400N) equipped with an Energy Dispersive Spec...

  11. Corrosion protection of SiC-based ceramics with CVD mullite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Auger, M.L.; Sarin, V.K. [Boston Univ., MA (United States). Dept. of Mfg. Engineering

    1997-12-01

    For the first time, crystalline mullite coatings have been chemically vapor deposited on SiC substrates to enhance its corrosion and oxidation resistance. Thermodynamic and kinetic considerations have been utilized to produce mullite coatings with a variety of growth rates, compositions, and morphologies. The flexibility of processing can be exploited to produce coated ceramics with properties tailored to specific applications and varied corrosive environments.

  12. Interfacial and biological properties of the gradient coating on polyamide substrate for bone substitute

    OpenAIRE

    Huang, Di; Niu, Lulu; Wei, Yan; Guo, Meiqing; Zuo, Yi; Zou, Qin; Hu, Yinchun; Chen, Weiyi; Li, Yubao

    2014-01-01

    Fabrication of bioactive and mechanical matched bone substitutes is crucial for clinical application in bone defects repair. In this study, nano-hydroxyapatite/polyamide (nHA/PA) composite was coated on injection-moulded PA by a chemical corrosion and phase-inversion technique. The shear strength, gradient composition and pore structure of the bioactive coating were characterized. Osteoblast-like MG63 cells were cultured on pure PA and composite-coated PA samples. The cells' adhesion, spread ...

  13. Bioactive composite gradient coatings of nano-hydroxyapatite/polyamide66 fabricated on polyamide66 substrates

    OpenAIRE

    Huang, Di; Zuo, Yi; Li, Jidong; Zou, Qin; Zhang, Li; Gong, Mei; Wang, Li; Li, Limei; Li, Yubao

    2012-01-01

    Tightly bonding of bioactive coating is the first crucial need for orthopaedic implants. This study describes a novel and convenient technique to prepare bioactive coating with high adhesion on orthopaedic substitutes made of polymeric matrix. Here, a chemical corrosion method has been adopted to fabricate a coating on the surface of injection-moulded polyamide66 (PA66) substrates by corrosive nano-hydroxyapatite/polyamide66 (n-HA/PA66) composite slurry. Scanning electron microscopy observati...

  14. Effect of Mo ion-implantation on the adhesion of diamond coatings

    CERN Document Server

    Yang Shie; Wang Xiao Ping; Li Hui; Ma Bing Xian; Qin Guang Yong; Zhang Bing Lin

    2002-01-01

    Diamond coatings were deposited on the cobalt-cemented tungsten carbide (YG6) substrates, which have been implanted with Mo ions, by microwave plasma CVD (MPCVD) method. The effect of ion-implantation on the adhesion of diamond coatings was studied. The results showed that the chemical compositions of cemented carbide substrate surfaces change obviously after Mo ion-implantation; and the adhesion strength between the CVD diamond coatings and the substrates implanted with Mo ions in proper concentration is improved remarkably

  15. Increased maize yield using slow-release attapulgite-coated fertilizers

    OpenAIRE

    Guan, Yu; Song, Chao; Gan, Yantai; Li, Feng-Min

    2014-01-01

    International audience Slow-release fertilizers could improve the productivity of field crops and reduce environmental pollution. So far, no slow-release fertilizers are suited for maize cultivation in semiarid areas of China. Therefore, we tested attapulgite-coated fertilizers. Attapulgite-coated fertilizers were prepared by dividing chemical fertilizers into three parts according to the nutrient demand of maize in its three main growth stages and coating each part with a layer of attapul...

  16. Friction, adhesion and corrosion performance of metallurgical coatings in HTGR-helium

    International Nuclear Information System (INIS)

    The friction-, adhesion-, thermal cycling- and corrosion performance of several metallurgical coating systems have been tested in a simulated HTGR-test atmosphere at elevated temperatures. The coatings were applied to a solid solution strengthened Ni-based superalloy. Component design requires coatings for the protection of mating surfaces, since under reactor operating conditions, contacting surfaces of metallic components under high pressures are prone to friction and wear damage. The coatings will have to protect the metal surface for 30 years up to 9500C in HTGR-helium. The materials tested were various refractory carbides with or without metallic binders and intermetallic compounds. The coatings evaluated were applied by plasma spraying-, detonation gun- and chemical vapor deposition techniques. These yielded two types of coatings which employ different mechanisms to improve the tribiological properties and maintain coating integrity. (Auth.)

  17. A perspective of microplasma oxidation (MPO) and vapor deposition coatings in surface engineering of aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    AWAD Samir Hamid; QIAN Han-cheng

    2004-01-01

    Over the past years, great achievements have been made in the development of coating technologies for surface improvement of aluminum alloys. Despite these achievements, the role in the market strongly depends on the ability of surface coating technology under technical and economic considerations to meet the increased demands for heavy tribological applications of aluminum alloys. Microplasma oxidation (MPO) technology has recently been studied as a novel and effective means to provide thick and hard ceramic coating with improved properties such as excellent load-bearing and wear resistance properties on aluminum alloys. The present work covers the evaluation of the performances of current single and duplex coatings combining MPO, physical vapor deposition (PVD), and plasma assisted chemical vapor deposition (PACVD) coatings on aluminum alloys. It suggests that the MPO coating is a promising candidate for design engineers to apply aluminum alloys to heavy load-bearing applications. The prospective future for the research on MPO coatings is introduced as well.

  18. Electrochemical properties and thermal stability of epoxy coatings electrodeposited on aluminium and modified aluminium surfaces

    Directory of Open Access Journals (Sweden)

    ZORICA M. KACAREVIC-POPOVIC

    2001-12-01

    Full Text Available The corrosion behaviour of epoxy coatings electrodeposited on aluminium, as well as on electrochemically and chemically modified aluminium were investigated during exposure to 3 % NaCl. Electrochemical impedance spectroscopy (EIS and thermogravimetric analysis (TGA were used for the determination of the protective properties of epoxy coatings on aluminium, anodized aluminium, phosphatized and chromatized-phosphatized aluminium. The protective properties of epoxy coatings on anodized and chromatized-phosphatized aluminium are significantly improved with respect to the same epoxy coatings on aluminium and phosphatized aluminium: higher values of the pore resitance and charge-transfer resistance, lower values of the coating capacitance, double-layer capacitance and relative permittivity (from EIS smaller amount of absorbed water inside the coating (From TGA. On the other hand, the lower values of the ipdt temperature indicate a lower thermal stability of the epoxy coatings on anodized and chromatized-phosphatized aluminium.

  19. ANALYSIS OF THE PROPERTIES OF NEW GROUPS OF COATINGS APPLIED IN HIGHLY LOADED MACHINE COMPONENTS

    Directory of Open Access Journals (Sweden)

    Kinga CHRONOWSKA

    2014-03-01

    Full Text Available The paper presents an overview of new groups of tribological coatings with complex microstructure deposited by PVD (Physical Vapour Deposition and CVD (Chemical Vapor Deposition techniques. The results of microstructure studies (TEM, mechanical and tribological properties of nanocomposite coatings nc-Cr2C/a-C:H and multilayers 16x(Ti/TiN were shown. The properties of these modern coatings are compared with the properties of two single coatings a-C:H and TiN. All coatings were deposited by magnetron sputtering on AISI 304 steel substrates. The hardness, elastic modulus and adhesion to the substrate studied by scratch testing were compared. The results showed the possibility of improving the wear resistance of the nanocomposite and multilayer coatings in comparison with conventional single coatings currently used in the machine industry.

  20. Microstructure characteristic and formation mechanism of crackfree TaC coating on C/C composite

    Institute of Scientific and Technical Information of China (English)

    LI Guo-dong; XIONG Xiang; HUANG Bai-yun

    2005-01-01

    The microstructure characteristic and formation mechanism of the crackfree and ablation-resistant TaC coating deposited on the C/C composite by Chemical Vapour Deposition(CVD) were investigated, using the reaction system of TaCl5-C3H6-H2-Ar. The results show that the nanosized pore structure formed in the TaC coating interior during CVD process is the main factor to reduce the hardness, elastic modulus, linear expansibility and inner thermal stress. Then crackfree coatings can be prepared and their thermal shock resistance can be enhanced. To obtain the dense and homogeneous matrix surface is necessary for the crackfree and low stress coating. The TaC coating structure that distributes from the dense matrix towards loose coating surface will result in the thick crackfree coating with good thermal shock resistance.

  1. Tribological properties of nanostructured n-Al2O3/Ni coatings deposited by plasma spraying

    Institute of Scientific and Technical Information of China (English)

    LI Chang-qing; MA Shi-ning; YE Xiong-lin

    2005-01-01

    Nanostructured n-Al2 Os/Ni feedstock for thermal spraying was manufactured by the method of chemical wrapping and spray drying. The nanostructured coating was sprayed with this feedstock. Tribological properties ofthe coatings and steel 45# were tested. Within the testing range, the friction coefficient of coatings against GCr15 steel decreased and the mass loss of coatings increased at first then decreased with the increase of load. Under each load, the coatings' friction coefficients and wear losses were lower than that of steel 45 # . Scanning electron micros copy and energy dispersive spectrometer analysis show that adhesion is the dominating wear mechanism, and fatigue exists at the same time. Material transferred from counter-part to the coating is the main factor which influences the coatings' friction coefficient and wear losses.

  2. Conductive epoxypolyamide coating composition

    Energy Technology Data Exchange (ETDEWEB)

    Mirabeau, M.N.; Rohrbacher, F.

    1991-10-01

    This patent describes a conductive coating composition comprising a film forming binder and pigment in a pigment to binder weight ratio of about 15:100 to 100:100. It comprises 40-70% by weight of an amine component having at least two reactive amine groups selected from the group consisting of an amine, polyamide, polyamido amine resin or mixtures thereof; and 30-60% by weight of an epoxy resin having at least two epoxy groups per resin molecule; wherein the pigment comprises an electrically conductive pigment that comprises silica selected from the group consisting of amorphous silica, a silica containing material or silica coated pigment, the silica being in association with a two- dimensional network of antimony-containing tin oxide crystallites in which the antimony content ranges from about 1-30% by weight of the tin oxide and the composition forms a coating having a surface conductivity of at least 100 Ransburg units.

  3. Melamine Polyimide Composite Fire Resistant Intumescent Coatings

    Directory of Open Access Journals (Sweden)

    Satish Chandra Gupta

    2013-07-01

    Full Text Available Components of intumescent coatings acid source, carbon source and blowing agent like melamine linked together by a binder provide cumulative fire retardant properties. When temperature of the coating surface reaches a critical temperature under the heat of flame, the surface begins to melt and is converted into highly viscous liquid. Simultaneously, reactions are initiated that result in the release of inert gases with low thermal conductivity. These gases are trapped inside the viscous fluid forming insulating char. The special composite of melamine polyimide, a C source and melamine a blowing agent showed high performance heat resistance in the present study. Polyimides have excellent heat and chemical resistance, excellent adhesion to a number of substrates and superior mechanical properties, such as high flexural modulus and compressive strength. Polyimides are also known to possess outstanding dimensional stability under loads, which allows their use in high temperature environments. Effect of the monomer on chemical reactivity between the binder and the intumescent additives has been studied by thermo-gravimetric analysis, differential scanning calorimeter and FTIR analysis. Thermal insulation studies by various intumescent composite coatings, applied on aluminium plates provided useful time temperature profiles.Defence Science Journal, 2013, 63(4, pp.442-446, DOI:http://dx.doi.org/10.14429/dsj.63.4871

  4. Melamine Polyimide Composite Fire Resistant Intumescent Coatings

    Directory of Open Access Journals (Sweden)

    Satish Chandra Gupta

    2013-07-01

    Full Text Available Components of intumescent coatings acid source, carbon source and blowing agent like melamine linked together by a binder provide cumulative fire retardant properties. When temperature of the coating surface reaches a critical temperature under the heat of flame, the surface begins to melt and is converted into highly viscous liquid. Simultaneously, reactions are initiated that result in the release of inert gases with low thermal conductivity. These gases are trapped inside the viscous fluid forming insulating char. The special composite of melamine polyimide, a C source and melamine a blowing agent showed high performance heat resistance in the present study. Polyimides have excellent heat and chemical resistance, excellent adhesion to a number of substrates and superior mechanical properties, such as high flexural modulus and compressive strength. Polyimides are also known to possess outstanding dimensional stability under loads, which allows their use in high temperature environments. Effect of the monomer on chemical reactivity between the binder and the intumescent additives has been studied by thermo-gravimetric analysis, differential scanning calorimeter and FTIR analysis. Thermal insulation studies by various intumescent composite coatings, applied on aluminium plates provided useful time temperature profiles.

  5. Interdiffusion Behavior in Aluminide Coatings for Power Generation Applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.; Pint, B.A.; Haynes, J.A.; Cooley, K.M.; Wright, I.G.

    2003-04-22

    One of the critical issues for the application of iron aluminide coatings is the loss of Al from the coating into the Fe-base substrate alloys which do not contain aluminum. The interdiffusion behavior between chemical vapor deposited (CVD) aluminide coatings and ferritic and austenitic substrates is being studied for times up to 10,000h in the temperature range of 500-800 C. Coatings were synthesized using a laboratory-scale CVD reactor on representative commercial ferritic (Fe-9Cr-1Mo) and austenitic (type 304L stainless steel) alloys. The aluminide coatings on both alloys typically consisted of a relatively thin (20-25 {micro}m) Al-rich outer layer and a thicker (150- 250 {micro}m) inner layer with less Al. The composition profiles before and after interdiffusion testing were measured by electron probe microanalysis (EPMA). The decrease of the Al content at the coating surface was not significant after extended diffusion times ({le} 5000h) at temperatures {le} 700 C. More interdiffusion occurred at 800 C in coatings on both Fe-9Cr-1Mo and 304L alloys. Particularly, a two-phase microstructure was formed in the outer coating layer on 304L after interdiffusion of 2000h at 800 C. The interdiffusion behavior also was simulated using a computer model COSIM (Coating Oxidation and Substrate Interdiffusion Model), which was originally developed for MCrAlY overlay coatings by NASA. Reasonable agreement was observed between the simulated and experimental composition profiles although more work is needed to confirm assumptions made in the model.

  6. HA-Coated Implant

    DEFF Research Database (Denmark)

    Daugaard, Henrik; Søballe, Kjeld; Bechtold, Joan E

    2014-01-01

    The goal of osseointegration of orthopedic and dental implants is the rapid achievement of a mechanically stable and long lasting fixation between living bone and the implant surface. In total joint replacements of cementless designs, coatings of calcium phosphates were introduced as a means...... of improving the fixation of implants. Of these, hydroxyapatite (HA) is the most widely used and most extensively investigated. HA is highly osseoconductive, and the positive effect is well documented in both basic and long-term clinical research [1–6]. This chapter describes experimental and clinical studies...... evaluating bone-implant fixation with HA coatings....

  7. Preparation of hydrophobic coatings

    Science.gov (United States)

    Branson, Eric D.; Shah, Pratik B.; Singh, Seema; Brinker, C. Jeffrey

    2009-02-03

    A method for preparing a hydrophobic coating by preparing a precursor sol comprising a metal alkoxide, a solvent, a basic catalyst, a fluoroalkyl compound and water, depositing the precursor sol as a film onto a surface, such as a substrate or a pipe, heating, the film and exposing the film to a hydrophobic silane compound to form a hydrophobic coating with a contact angle greater than approximately 150.degree.. The contact angle of the film can be controlled by exposure to ultraviolet radiation to reduce the contact angle and subsequent exposure to a hydrophobic silane compound to increase the contact angle.

  8. Formation and characterization of cerium conversion coatings on magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    LI Lingjie; LEI Jinglei; YU Shenghai; TIAN Yujing; JIANG Qiquan; PAN Fusheng

    2008-01-01

    Chemical conversion treatment by rare earth metal salt solution was considered as an alternative to chromium chemical conversion treatment to improve the corrosion resistance of magnesium alloys. In this study, cerium conversion coatings formed on AZ31 magnesium alloy were characterized and the formation mechanism was discussed. X-ray photoelectron spectroscopy (XPS) analysis showed that cerium conversion coating consisted of cerium hydroxides/oxides, in which both tetravalent cerium Ce(IV) and trivalent cerium Ce(III) species co-existed. Cerium conversion coating was a two-layer structure. Atomic force microscopy (AFM) images revealed that the morphology of the inside layer was different from that of the outside one, which was responsible for the inherent adhesive weakness of the coating. Corrosion potential (Ecorr) measurements indicated that poor adhesion limited the improvement of the corrosion resistance of the coating. During the treating process, the increased pH value of the cerium salt solution led to the precipitation of cerium hydroxides/oxides. The formation kinetics of the coating followed a parabolic curve.

  9. Tough-coated hard powders for hardmetals of novel properties

    International Nuclear Information System (INIS)

    The properties and performance of conventional materials and composites are constrained by solubility limits, diffusion coefficients, and compatibility of physical and chemical constituent properties in their phase equilibria. To escape these limits, ingenious ways of combining strength, toughness, and wear resistance by way of various coatings and laminations have been devised. These coated tools are systematically discarded after only about 10 % of their wear tolerance has been used. Tough-coated hard powders (TCHP), patented by EnDurAloy (USA), are hard refractory particles CVD coated with nanolayers of WC and Co. Consolidation of TCHP creates an engineered homogeneous cellular structure whose interconnected tough WC-Co 'shells' each contain a wear-resistant core (e.g., TiN). In TCHP's, the coating is throughout the tool, not only on the surface, combining the strength, heat resistance, and toughness of cemented carbides with the chemical and abrasion wear resistance of harder materials. As wear progresses, new wear-resistant material continuously replaces the working surfaces and edges of the tool until its geometry reaches its maximum limits. TCHP tools are then reusable many times. Specific coating and consolidation processes, characterization of compacts, and test comparisons with conventional materials are discussed. (author)

  10. Electrolytic deposition and corrosion resistance of Zn–Ni coatings obtained from sulphate-chloride bath

    Indian Academy of Sciences (India)

    Katarzyna Wykpis; Magdalena Popczyk; Antoni Budniok

    2011-07-01

    Zn–Ni coatings were deposited under galvanostatic conditions on steel substrate (OH18N9). The influence of current density of deposition on the surface morphology, chemical and phase composition was investigated. The corrosion resistance of Zn–Ni coatings obtained at current density 10–25 mA cm-2 are measured, and are compared with that of metallic cadmium coating. Structural investigations were performed by the X-ray diffraction (XRD) method. The surface morphology and chemical composition of deposited coatings were studied using a scanning electron microscope (JEOL JSM-6480) with EDS attachment. Studies of electrochemical corrosion resistance were carried out in the 5% NaCl, using potentiodynamic and electrochemical impedance spectroscopy (EIS) methods. On the ground of these research, the possibility of deposition of Zn–Ni coatings contained 24–26% at. Ni was exhibited. It was stated, that surface morphology, chemical and phase composition of these coatings are practically independent on current density of deposition. On the basis of electrochemical investigations it was found that corrosion resistance of these Zn–Ni coatings is also independent of current density. These coatings are more corrosion resistant in 5% NaCl solution than metallic cadmium. It was suggested that the Zn–Ni coating may be used as a substitute for toxic cadmium.

  11. Methods and means for coating paper by film coating

    NARCIS (Netherlands)

    van der Maarel, Marc; Ter Veer, Arend Berend Cornelis; Vrieling-Smit, Annet; Delnoye, Pierre

    2015-01-01

    This invention relates to the field of paper coating, more in particular to means and methods for providing paper with at least one layer of pigment using film coating to obtain a well printable surface. Provided is a method for preparing coated paper comprising the steps of: a) providing a pigmente

  12. Using sol-gel component as additive to foundry coatings to improve casting quality

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Poulsen, T.; Gravesen, B.;

    2012-01-01

    The improvement of foundry coatings to enhance performance is important. This paper investigates the effect of using sol‐gel component as an additive to foundry coatings applied on chemically bonded sand cores. Three parameters at three levels each were investigated using Taguchi experimental...

  13. Study of the Structural and Mechanical Properties of Nanocrystalline TiAlSiN Gradient Coatings

    NARCIS (Netherlands)

    Cholakova, T.; Chitanov, V.; Chaliampalias, D.; Kolaklieva, L.; Kakanakov, R.; Bahchedjiev, Ch.; Petkov, N.; Pashinski, Ch.; Vourlias, G.; Vouroutzis, N.; Polychroniadis, E.; Wang, Y.; Meletis, E. I.

    2014-01-01

    A study of the structural and mechanical properties of nanocrystalline TiAlSiN gradient coatings deposited by cathodic arc deposition techniques at 500 degrees C and post-annealed at 525 degrees C is presented. Analysis of the coatings, chemical composition and microstructure revealed that the coati

  14. Performance Comparison of Steam-Based and Chromate Conversion Coatings on Aluminum Alloy 6060

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

    2015-01-01

    In this study, oxide layers generated on aluminum alloy 6060(UNS A96060) using a steam-based process were compared with conventional chromate and chromate-phosphate conversion coatings. Chemical composition and microstructure of the conversion coatings were investigated and their corrosion...

  15. Selective formation of diamond-like carbon coating by surface catalyst patterning

    DEFF Research Database (Denmark)

    Palnichenko, A.V.; Mátéfi-Tempfli, M.; Mátéfi-Tempfli, Stefan;

    2004-01-01

    The selective formation of diamond-like carbon coating by surface catalyst patterning was studied. DLC films was deposited using plasma enhanced chemical vapor deposition, filtered vacuum arc deposition, laser ablation, magnetron sputtering and ion-beam lithography methods. The DLC coatings were...

  16. Electrochemical niobium oxide coating in molten NaNO3-KNO3

    International Nuclear Information System (INIS)

    Kinetics of anodic oxide film growth on niobium in molten NaNO3-KNO3 (50 mol %) is studied in galvanostatic and potentiostatic conditions. Basic kinetic parameters of the oxide-coating process are determined. Chemical composition of the oxide coatings is established

  17. Preparation and characterization of enamel coating on pure titanium as a hydrogen penetration barrier

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Jie, E-mail: taojie@nuaa.edu.cn [College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016 (China); Guo, Xunzhong [College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016 (China); Huang, Zhendong [Graduate School of Human and Environmental Studies, Kyoto University, oshida-Nihonmatsu-Cho, Sakyo-Ku, Kyoto shi 606-8501 (Japan); Liu, Hongbing [Shanghai Aircraft Manufacturing Co,. Ltd, Shanghai 200436 (China); Wang, Tao [College of Material Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu 210016 (China)

    2013-06-15

    Highlights: ► The enamel coating was prepared by spin-coating and enameling method. ► The dense enamel coatings were chemically bonded with TA1 substrate. ► The coatings possessed better thermal shock resistance property. ► The coatings had excellent ball-dropping impact properties. ► The enamel coating exhibited a good barrier effect to hydrogen isotope penetration. -- Abstract: The enamel coating with a thickness of 90–110 × 10{sup −6} m was prepared on TA1 substrate by spin-coating and enameling to solve the problems of hydrogen isotope penetration for commercial pure titanium TA1. The microstructure and the interfacial morphology of the samples were characterized respectively by X-ray diffraction, optical and scanning electron microscopy. The profiles of main elements at the interface were analyzed by EDS line-scanning. The experimental results indicated that the dense enamel coatings were chemically bonded with TA1 substrate, and possessed better thermal shock resistance and ball-dropping impact properties. It was concluded from the results of hydrogen charging test with Vickers microhardness measurement and deuterium penetration experiments that the as-prepared dense enamel coating exhibited a good barrier effect to hydrogen isotope penetration.

  18. Microstructure and electrochemical behavior of cerium conversion coating modified with silane agent on magnesium substrates

    Science.gov (United States)

    Lei, Li; Shi, Jing; Wang, Xin; Liu, Dan; Xu, Haigang

    2016-07-01

    The cerium conversion coating with and without different concentrations of silane agent bis-(γ-triethoxysilylpropyl)-tetrasulfide (BTESPT) modification is obtained on magnesium alloys. Detailed properties of the coatings and the role of BTESPT as an additive are studied and followed with careful discussion. The coating morphology, wettability, chemical composition and corrosion resistance are characterized by scanning electronic microscope (SEM), water contact-angle, X-ray photoelectron spectroscopy (XPS), potentiodynamic measurements and electrochemical impedance spectroscopy (EIS). The electrochemical behavior of the coatings is investigated using EIS. The results indicate that the coating morphology and composition can be controlled by changing silane concentration. The combination of cerium ions and silane molecules could promote the formation of more homogenous and higher hydrophobic coating. The coating turns to be more compact and the adhesive strength between the coating and the magnesium substrate are strongly improved with the formation of Sisbnd Osbnd Si and Sisbnd Osbnd M chemical bonds. The optimum corrosion resistance of the coating in the corrosive media is obtained by 25 ml L-1 BTESPT modification. This whole study implies that the cerium conversion coating modified with certain silane agent deserves cautiousness before its application for corrosion resistance.

  19. Surface molecular imprinting onto fluorescein-coated magnetic nanoparticlesvia reversible addition fragmentation chain transfer polymerization: A facile three-in-one system for recognition and separation of endocrine disrupting chemicals

    Science.gov (United States)

    Li, Ying; Dong, Cunku; Chu, Jia; Qi, Jingyao; Li, Xin

    2011-01-01

    In this study, we present a general protocol for the making of surface-imprinted magnetic fluorescence beads viareversible addition-fragmentation chain transfer polymerization. The resulting composites were characterized by X-ray diffraction analysis, transmission electron microscopy, scanning electron microscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy, and energy dispersive spectroscopy. The as-synthesized beads exhibited homogeneous polymer films (thickness of about 5.7 nm), spherical shape, high fluorescence intensity and magnetic property (Magnetization (Ms) = 3.67 emu g-1). The hybrids bind the original template 17β-estradiol with an appreciable selectivity over structurally related compounds. In addition, the resulting hybrids performed without obvious deterioration after five repeated cycles. This study therefore demonstrates the potential of molecularly imprinted polymers for the recognition and separation of endocrine disrupting chemicals.In this study, we present a general protocol for the making of surface-imprinted magnetic fluorescence beads viareversible addition-fragmentation chain transfer polymerization. The resulting composites were characterized by X-ray diffraction analysis, transmission electron microscopy, scanning electron microscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy, and energy dispersive spectroscopy. The as-synthesized beads exhibited homogeneous polymer films (thickness of about 5.7 nm), spherical shape, high fluorescence intensity and magnetic property (Magnetization (Ms) = 3.67 emu g-1). The hybrids bind the original template 17β-estradiol with an appreciable selectivity over structurally related compounds. In addition, the resulting hybrids performed without obvious deterioration after five repeated cycles. This study therefore demonstrates the potential of molecularly imprinted polymers for the recognition and separation of endocrine disrupting chemicals. Electronic

  20. Thermal stability of protective coatings produced on nickel based superalloy

    Directory of Open Access Journals (Sweden)

    M. Pytel

    2012-04-01

    Full Text Available Purpose: In this paper the results of high temperature cyclic oxidation tests of the protective diffusion coatings were presented. One of the main purposes of this work was to produce three different types of protective coatings by three different methods, i.e. slurry method, vapour phase aluminizing (VPA and chemical vapour deposition (CVD, applied on nickel based René 80 superalloy substrate.Design/methodology/approach: The high temperature cyclic oxidation tests were carried out in 23h cycles at constant temperature 1100°C using Carbolite CWF 1300 chamber furnace. The samples were removed outside and were weighted after each cycle. The microstructure investigations of all kinds of the coatings were conducted by the use of light microscope (Nikon Epiphot 300 and a scanning electron microscope (Hitachi S-3400N. In the analysis influence of each method have been taken into consideration, i.e. especially influence of the kind of process on microstructure, coating thickness, chemical composition, first of all aluminium content (in outer ȕ-NiAl layer so-called additive layer, diffusion layer and substrate. For the chemical composition examination x-ray energy dispersive (EDS method was applied using Thermo equipment.Findings: It was found that the best high cyclic oxidation resistance of coating was obtained using CVD method (the maximal increase of samples weight after 28th cycle was observed, whereas in case of the slurry sample after 3rd and VPA after 5th.Research limitations/implications: The research results will be used in the future in order to increase coating thickness, aluminium content and to produce Pt, Pd, Zr, Hf and Si modified aluminide coatings.Practical implications: The CVD method will be used to coat internal passages of turbine blades, for example to produce modified aluminide bond coats on single crystal nickel based superalloys.Originality/value: Chemical vapour deposition is an unique method which is a “pure method

  1. Nanocarbon-Coated Porous Anodic Alumina for Bionic Devices

    Directory of Open Access Journals (Sweden)

    Morteza Aramesh

    2015-08-01

    Full Text Available A highly-stable and biocompatible nanoporous electrode is demonstrated herein. The electrode is based on a porous anodic alumina which is conformally coated with an ultra-thin layer of diamond-like carbon. The nanocarbon coating plays an essential role for the chemical stability and biocompatibility of the electrodes; thus, the coated electrodes are ideally suited for biomedical applications. The corrosion resistance of the proposed electrodes was tested under extreme chemical conditions, such as in boiling acidic/alkali environments. The nanostructured morphology and the surface chemistry of the electrodes were maintained after wet/dry chemical corrosion tests. The non-cytotoxicity of the electrodes was tested by standard toxicity tests using mouse fibroblasts and cortical neurons. Furthermore, the cell–electrode interaction of cortical neurons with nanocarbon coated nanoporous anodic alumina was studied in vitro. Cortical neurons were found to attach and spread to the nanocarbon coated electrodes without using additional biomolecules, whilst no cell attachment was observed on the surface of the bare anodic alumina. Neurite growth appeared to be sensitive to nanotopographical features of the electrodes. The proposed electrodes show a great promise for practical applications such as retinal prostheses and bionic implants in general.

  2. Failure mechanism for thermal fatigue of thermal barrier coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Giolli, C.; Scrivani, A.; Rizzi, G. [Turbocoating S.p.A., Rubbiano di Solignano (Italy); Borgioli, F. [Firenze Univ., Sesto Fiorentino (Italy); Bolelli, G.; Lusvarghi, L. [Univ. di Modena e Reggio Emilia, Modena (Italy)

    2008-07-01

    High temperature thermal fatigue causes the failure of Thermal Barrier Coating (TBC) systems. Due to the difference in thickness and microstructure between thick TBCs and traditional thin TBCs, they cannot be assumed a-priori to possess the same failure mechanisms. Thick TBCs, consisting of a CoNiCrAlY bond coat and Yttria Partially Stabilised Zirconia top coat with different values of porosity, were produced by Air Plasma Spray. Thermal fatigue resistance limit of TBCs was tested by Furnace Cycling Tests (FCT) according to the specifications of an Original Equipment Manufacturer (OEM). TBC systems were analyzed before and after FCT. The morphological and chemical evolution of CoNiCrAlY/TGO microstructure was studied. Sintering effect, residual stress, phase transformation and fracture toughness were evaluated in the ceramic Top Coat. All the tested samples passed FCT according to the specification of an important OEM. Thermal fatigue resistance increases with the amount of porosity in the top coat. The compressive in-plane stresses increase in the TBC systems after thermal cycling, nevertheless the increasing rate has a trend contrary to the porosity level of top coat. The data suggest that the spallation happens at the TGO/Top Coat interface. The failure mechanism of thick TBCs subjected to thermal fatigue was eventually found to be similar to the failure mechanism of thin TBC systems made by APS. (orig.)

  3. Initial Assessment of Environmental Barrier Coatings for the Prometheus Project

    Energy Technology Data Exchange (ETDEWEB)

    M. Frederick

    2005-12-15

    Depending upon final design and materials selections, a variety of engineering solutions may need to be considered to avoid chemical degradation of components in a notional space nuclear power plant (SNPP). Coatings are one engineered approach that was considered. A comprehensive review of protective coating technology for various space-reactor structural materials is presented, including refractory metal alloys [molybdenum (Mo), tungsten (W), rhenium (Re), tantalum (Ta), and niobium (Nb)], nickel (Ni)-base superalloys, and silicon carbide (Sic). A summary description of some common deposition techniques is included. A literature survey identified coatings based on silicides or iridium/rhenium as the primary methods for environmental protection of refractory metal alloys. Modified aluminide coatings have been identified for superalloys and multilayer ceramic coatings for protection of Sic. All reviewed research focused on protecting structural materials from extreme temperatures in highly oxidizing conditions. Thermodynamic analyses indicate that some of these coatings may not be protective in the high-temperature, impure-He environment expected in a Prometheus reactor system. Further research is proposed to determine extensibility of these coating materials to less-oxidizing or neutral environments.

  4. Proceedings of the 1987 coatings for advanced heat engines workshop

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

    This Workshop was conducted to enhance communication among those involved in coating development for improved heat engine performance and durability. We were fortunate to have Bill Goward review the steady progress and problems encountered along the way in the use of thermal barrier coatings (TBC) in aircraft gas turbine engines. Navy contractors discussed their work toward the elusive goal of qualifying TBC for turbine airfoil applications. In the diesel community, Caterpillar and Cummins are developing TBC for combustion chamber components as part of the low heat rejection diesel engine concept. The diesel engine TBC work is based on gas turbine technology with a goal of more than twice the thickness used on gas turbine engine components. Adoption of TBC in production for diesel engines could justify a new generation of plasma spray coating equipment. Increasing interests in tribology were evident in this Workshop. Coatings have a significant role in reducing friction and wear under greater mechanical loadings at higher temperatures. The emergence of a high temperature synthetic lubricant could have an enormous impact on diesel engine design and operating conditions. The proven coating processes such as plasma spray, electron-beam physical vapor deposition, sputtering, and chemical vapor deposition have shown enhanced capabilities, particularly with microprocessor controls. Also, the newer coating schemes such as ion implantation and cathodic arc are demonstrating intriguing potential for engine applications. Coatings will play an expanding role in higher efficiency, more durable heat engines.

  5. Weathering properties of wood species treated with different coating applications

    Directory of Open Access Journals (Sweden)

    Ozlem Ozgenc

    2012-11-01

    Full Text Available The objective of this study was to evaluate the discoloration of European beech (Fagus sylvatica and Scots pine (Pinus sylvestris specimens treated with different chemicals and surface coated with different UV absorbers before being subjected to artificial weathering. The results showed that the influence of coatings containing UV absorbers (UV screeners micronized TiO2 and UVA of hydroxyphenyl-s-triazine types were similar to each other. The UV screener TiO2 led to the least discoloration of the coated wood surface, closely followed by the UVA of hydroxyphenyl-s-triazines (HPT. The color stability was determined to be better for pine wood treated with micronized copper preservative coated with UV absorber, in comparison to when it was only coated with UV absorbers and then subjected to weathering. Microscopic observation revealed that the clear-coats penetration behavior was different in wood preservative-treated and in untreated wood of Scots pine, which has various extractives. However, the color stability and coating penetration was nearly the same in beech wood treated with preservatives and in untreated beech wood. We provide an explanation for why these effects occurred and discuss the implications of our findings for the development of weather-resistant wood materials.

  6. Multilayer optical coating fabrication by dc magnetron reactive sputtering

    International Nuclear Information System (INIS)

    A conventional box coating chamber has been equipped with three dc magnetron sputtering cathodes, reactive gas (O2, N2, H2) pressure and flow control, planetary substrate holder, and optical monitoring to produce a low-temperature batch coating system for multilayer optical coating fabrication using oxides, nitrides, semiconductors and semitransparent metals. The system realizes the benefits traditionally derived from this geometry: maximum area of uniform coating thickness, spatially-averaged coating flux impingement angles, and precise thickness monitoring. The use of sputtering cathodes adds the benefits of increased flexibility in choice of materials deposited, increased adatom energy at the substrate, and increased chemical reactivity in a gas discharge. Dense, durable, fully-reacted dielectric coatings are achieved at low processing temperatures. Metal targets (sources) are used for ease of fabrication, and dc power avoids radio-frequency impedance matching requirements. The chamber and components are described and operation of the cathodes explained. Thickness uniformity profiles, deposition rates, and substrate temperature data are related. A list of materials investigated to date is presented with pertinent optical properties and intrinsic mechanical stress values. Illustrative performance examples for multilayer coatings on glasses and plastics are included

  7. EB-curing of coatings on wood composite boards

    International Nuclear Information System (INIS)

    The industrial radiation processing using low energy electron beam (EB) accelerators lower than 300 keV offers high speed, safe technologies for the chemical conversion of thin layer coatings. Because of the nonselective mode of initiating chain reaction polymerization involving free radicals in synthetic coating layers and suitable substrates, the EB curing of the coatings on woods and papers has particular advantage. Hungary decided to start an up-to-date EB line to process cement-bound (CB) wood chipboards with pigmented acrylic coatings. The CB wood chipboards contain more than 60 % of portland cement and up to 40 % of wood particles. They are produced as large boads of 6 - 16 mm thickness. In their fireproof character and other aspects, they are similar to asbestos-cement boards without containing carcinagenic asbestos, and are stable against moisture and atmospheric influences. EB-cured acrylate coating improved further those properties, and makes them valuable structural material. Oligomers and monomers as the main components of EB curable coatings, the irradiation with a Van de Graaff type electron accelerator of 2 MeV and the results are reported. The oligomers play the most important role in the formation of radiation curable coatings. (K.I.)

  8. Preparation of aluminide coatings at relatively low temperatures

    Institute of Scientific and Technical Information of China (English)

    ZHAN Zhao-lin; HE Ye-dong; WANG De-ren; GAO Wei

    2006-01-01

    A method was presented to prepare aluminide coatings on metals by combining the pack aluminizing with the ball impact process. This technique applied mechanical vibration to a retort, which was loaded with pack-aluminizing powder, specimens and alloy balls. Pack aluminizing was carried out with repeated ball impact, which accelerated chemical reactions and atomic diffusion.Aluminide coatings were formed at a relatively lower temperature (below 600 ℃) and in a shorter treatment time, compared with the conventional pack aluminizing. The effects of the operation temperature and the treatment time on the formation of the coatings were analysed. The SEM, EDS and XRD analysis results show that the aluminide coatings appear to be homogeneous, with a high density and free of porosity, and have excellent adherence to the substrate. The coatings mainly consist of Al-rich phases such as η-Fe2Al5,θ-FeAl3 and CrAl5. Oxidation resistance was studied by high-temperature tests. The formation mechanism of the Al-coatings was also investigated. This technique provides a new approach for industrial diffusion coatings with great energy and time savings.

  9. Cavitation erosion resistance of microarc oxidation coating on aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Feng [School of Mechanical Engineering, Southeast University, Nanjing, 211189 (China); Jiang, Shuyun, E-mail: jiangshy@seu.edu.cn [School of Mechanical Engineering, Southeast University, Nanjing, 211189 (China); Liang, Jun [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China)

    2013-09-01

    Two ceramic coatings are prepared on 2124 aluminum alloy by microarc oxidation (MAO) technology. To explore the cavitation erosion resistance of the MAO coating, cavitation tests were performed by using a rotating-disk test rig. The mass losses, surface morphologies, chemical compositions and the phase constituents of the samples after cavitation tests were examined by using digital balance, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The results indicate that the MAO coatings can extend the incubation period of aluminum alloy, and thus enhance the cavitation erosion resistance as compared to the untreated aluminum alloy samples. After duration of 63 h cavitation test, a lot of erosion pits and the particles in various shapes can be observed on the surfaces of the aluminum alloy samples, while only a few erosion pits are observed on the MAO coatings. Moreover, the mean depths of erosion on the MAO coatings are lower in the first 30 h and are independent on erosion time. The results show that the cavitation erosion of MAO coating is governed by water mechanical impaction, resulting from the effects of brittle fracture of the MAO coating.

  10. Method for forming a coating film on vessels

    International Nuclear Information System (INIS)

    A method for forming a solvent-resistant, water-repellent, durable coating film on the surface of medical vessels is provided. The method comprises coating a vessel with an organic solution or an aqueous emulsion of silicone oil, drying it and then exposing it to a radiation. Dose of the radiation should not be lower than 1 x 103 rad. The silicone oil usable is mono- or di-alkyl or -phenyl polysiloxane having a viscosity of 10 to 1000 centistokes. Glass- or plastic-made medical vessels can be coated by this method. A durable film resistant to mechanical and chemical actions is obtained. In one example, a drug vial was coated with a 4% solution of dimethylpolysiloxane (350 centistokes) in CCl4 by spraying method and then exposed to varying dose of cobalt 60 radiation. It was washed with water and boiled at 1000C for 3 hrs. With a total dose of 1 x 104 rad or above, a good water-repellency was attained on the whole coated surface. According to the usual coating methods, there occurred many non-repellent parts (in case of heating to 3000C for 0.5 hr instead of irradiation) or the water-repellency nearly disappeared on the whole coated surface (in case of IR irradiation for 1 hr). (Kaichi, S.)

  11. Carbon coatings for medical implants

    OpenAIRE

    K. Bakowicz-Mitura; P. Couvrat; I. Kotela; P. Louda; D. Batory; J. Grabarczyk

    2007-01-01

    Purpose: In this paper we report in vitro and in vivo results of Nanocrystalline Diamond Coatings whichare used in medicine onto medical implants The very important property of carbon coatings is the protectionliving organism against the metalosis. Different medical implants with complicated shapes are covering byNanocrystalline Diamond Coatings by RF dense plasma CVD.Design/methodology/approach: 1) Material characterizations of deposited coatings have been evaluated by using:Transmission Ele...

  12. Foam coating of filtration media

    OpenAIRE

    Johansson, Mirva

    2015-01-01

    The objective of this thesis was to find out if foam coating could be applied to non-woven filtration media. The goal was to increase collection efficiency without significantly decreasing air permeability. In the theoretical part, foams and their characteristics were the centre of attention. Coating in general and, of course, foam coating were also studied. The empirical part consisted of series of foaming experiments and pilot scale coating experiments. In the foaming experiments differ...

  13. Optical coatings for fiber lasers

    Institute of Scientific and Technical Information of China (English)

    HONG Dong-mei; ZHU Zhen; YUE Wei

    2005-01-01

    Fiber laser is the future development direction for the high energy lasers. This paper describs two kinds of optical coatings for fiber laser, including long and short wave pass filters. The one characteristic of fiber laser coatings lies in that coatings should separate two closely wavelength light including laser pump wavelength (980 nm) and laser irradiation wavelength(1 050~1 100 nm). At the same time, the coatings should have high laser damage threshold.

  14. Antimicrobial-Coated Granules for Disinfecting Water

    Science.gov (United States)

    Akse, James R.; Holtsnider, John T.; Kliestik, Helen

    2011-01-01

    Methods of preparing antimicrobialcoated granules for disinfecting flowing potable water have been developed. Like the methods reported in the immediately preceding article, these methods involve chemical preparation of substrate surfaces (in this case, the surfaces of granules) to enable attachment of antimicrobial molecules to the surfaces via covalent bonds. A variety of granular materials have been coated with a variety of antimicrobial agents that include antibiotics, bacteriocins, enzymes, bactericides, and fungicides. When employed in packed beds in flowing water, these antimicrobial-coated granules have been proven effective against gram-positive bacteria, gram-negative bacteria, fungi, and viruses. Composite beds, consisting of multiple layers containing different granular antimicrobial media, have proven particularly effective against a broad spectrum of microorganisms. These media have also proven effective in enhancing or potentiating the biocidal effects of in-line iodinated resins and of very low levels of dissolved elemental iodine.

  15. Hard, infrared black coating with very low outgassing

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmenko, P J; Behne, D M; Casserly, T; Boardman, W; Upadhyaya, D; Boinapally, K; Gupta, M; Cao, Y

    2008-06-02

    Infrared astronomical instruments require absorptive coatings on internal surfaces to trap scattered and stray photons. This is typically accomplished with any one of a number of black paints. Although inexpensive and simple to apply, paint has several disadvantages. Painted surfaces can be fragile, prone to shedding particles, and difficult to clean. Most importantly, the vacuum performance is poor. Recently a plasma enhanced chemical vapor deposition (PECVD) process was developed to apply thick (30 {micro}m) diamond-like carbon (DLC) based protective coatings to the interior of oil pipelines. These DLC coatings show much promise as an infrared black for an ultra high vacuum environment. The coatings are very robust with excellent cryogenic adhesion. Their total infrared reflectivity of < 10% at normal incidence approaches that of black paints. We measured outgas rates of <10{sup -12} Torr liter/sec cm{sup 2}, comparable to bare stainless steel.

  16. Laser Assisted Additively Manufactured Transition Metal Coating on Aluminum

    Science.gov (United States)

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

    2016-07-01

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

  17. Laser Assisted Additively Manufactured Transition Metal Coating on Aluminum

    Science.gov (United States)

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

    2016-07-01

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

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

    Science.gov (United States)

    Hansen, Natanya M L; Plackett, David

    2008-06-01

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

  19. Erosion Testing of Coatings for V-22 Aircraft Applications

    Directory of Open Access Journals (Sweden)

    G. Y. Richardson

    2003-01-01

    Full Text Available High-velocity (183 m/sec sand erosion tests in a wind tunnel were conducted to evaluate developmental coatings from three separate companies under funding by the Navy's phase I small business innovative research program. The purpose of the coatings was to address a particular problem the V-22 tilt-rotor aircraft (Osprey was having with regard to ingestion of sand particles by a titanium impeller that was associated with the aircraft's environmental control system. The three coatings that were deposited on titanium substrates and erosion-tested included (1 SixCy/DLC multilayers deposited by chemical vapor deposition (CVD; (2 WC/TaC/TiC processed by electrospark deposition; and (3 polymer ceramic mixtures applied by means of an aqueous synthesis. The erosion test results are presented; they provided the basis for assessing the suitability of some of these coatings for the intended application.

  20. Patterning and biofunctionalization of antifouling hyperbranched polyglycerol coatings.

    Science.gov (United States)

    Moore, Eli; Delalat, Bahman; Vasani, Roshan; Thissen, Helmut; Voelcker, Nicolas H

    2014-07-14

    We demonstrate the patterned biofunctionalization of antifouling hyperbranched polyglycerol (HPG) coatings on silicon and glass substrates. The ultralow fouling HPG coatings afforded straightforward chemical handles for rapid bioconjugation of amine containing biomolecular species. This was achieved by sodium periodate oxidation of terminal HPG diols to yield reactive aldehyde groups. Patterned microprinting of sodium periodate and cell adhesion mediating cyclic peptides containing the RGD sequence resulted in an array of covalently immobilized bioactive signals. When incubated with mouse fibroblasts, the HPG background resisted cell attachment whereas high density cell attachment was observed on the peptide spots, resulting in high-contrast cell microarrays. We also demonstrated single-step, in situ functionalization of the HPG coatings by printing periodate and peptide concurrently. Our results demonstrate the effectiveness of antifouling and functionalized HPG graft polymer coatings and establish their use in microarray applications for the first time. PMID:24956414