Showing papers on "Coating published in 2001"

Material fundamentals and clinical performance of plasma-sprayed hydroxyapatite coatings: A review

Abstract: The clinical use of plasma-sprayed hydroxyapatite (HA) coatings on metal implants has aroused as many controversies as interests over the last decade. Although faster and stronger fixation and more bone growth have been revealed, the performance of HA-coated implants has been doubted. This article will initially address the fundamentals of the material selection, design, and processing of the HA coating and show how the coating microstructure and properties can be a good predictor of the expected behavior in the body. Further discussion will clarify the major concerns with the clinical use of HA coatings and introduce a comprehensive review concerning the outcomes experienced with respect to clinical practice over the past 5 years. A reflection on the results indicates that HA coatings can promote earlier and stronger fixation but exhibit a durability that can be related to the coating quality. Specific relationships between coating quality and clinical performance are being established as characterization methods disclose more information about the coating.

Method of depositing an amorphous carbon layer

Abstract: A method of forming an integrated circuit using an amorphous carbon film. The amorphous carbon film is formed by thermally decomposing a gas mixture comprising a hydrocarbon compound and an inert gas. The amorphous carbon film is compatible with integrated circuit fabrication processes. In one integrated circuit fabrication process, the amorphous carbon film is used as a hardmask. In another integrated circuit fabrication process, the amorphous carbon film is an anti-reflective coating (ARC) for deep ultraviolet (DUV) lithography. In yet another integrated circuit fabrication process, a multi-layer amorphous carbon anti-reflective coating is used for DUV lithography.

Multilayered Titania, Silica, and Laponite Nanoparticle Coatings on Polystyrene Colloidal Templates and Resulting Inorganic Hollow Spheres

Abstract: The applicability of the layer-by-layer (LbL) technique for the formation of a range of polymer-core inorganic-shell particles and inorganic hollow spheres is demonstrated Titanium dioxide, silica, and Laponite nanoparticles were used as the inorganic building blocks for multilayer formation on polystyrene (PS) sphere templates Composite organic−inorganic particles were formed by the controlled assembly of the preformed nanoparticles in alternation with oppositely charged polyelectrolytes onto PS microspheres The influence of nanoparticle type, shape (spherical to sheetlike), and size (3−100 nm), and the diameter of the PS sphere templates (210−640 nm) on the formation of multilayer shells was examined by transmission and scanning electron microscopy In addition, the LbL technique for coating polymer spheres has been shown to be adaptable with small variations in the coating steps used to optimize the nanoparticle coatings of the different materials For example, the number of polyelectrolyte multilay

Sol−Gel Nanocoating: An Approach to the Preparation of Structured Materials

Abstract: Nanocoating, the covering of materials with a layer on the nanometer scale, or covering of a nanoscale entity, to form nanocomposites and structured materials using the sol−gel process is reviewed. Templates from spherical nanoparticles to complex bicontinuous networks are discussed where either the coated material or the structured inorganic hollow frame resulting after removal of the template are of interest in fields of application ranging from information storage to catalysis. The sol−gel procedure allows coating of templates with complex shapes on the micrometer to nanometer scale, which some commonly used coating procedures cannot achieve. In addition, sol−gel coating techniques can be applied to delicate systems without disruption of their structure or functionality, for example, the coating of biocomplexes or organic aggregates, such as organogelators. Three-dimensional structures with elaborate pore architectures, such as polymer membranes and gels, can also be infiltrated with sol−gel solutions ...

Polyol-Mediated Preparation of Nanoscale Oxide Particles.

Abstract: Largely monodisperse, crystalline nanoscale oxide particles (for example, Cu2 O, TiO2 , Nb2 O5 ) are preparatively accessible with the polyol method. The colloidal suspensions of the particles thus obtained can be employed readily for the homogeneous coating of various substrates (for example, glass plates, Al2 O3 powder).

Structure-performance relations in nanocomposite coatings

Abstract: Properties of hard nanocomposite coatings, especially hardness, can be explained by their nanostructure. Hardness maxima are found for different nanocrystalline/amorphous materials deposited by different techniques at typically 20% of the amorphous phase. A zone model is proposed which correlates the hardness to the relative phase content. The hardness of nanocomposite coatings peaks at the common minimum of the grain size of the crystalline phase and the grain separation. For an adequate description of the performance of a coating, the thermal stability, oxidation behavior and frictional behavior should be included in addition to hardness. In a friction situation involving at least two friction partners, the overall behavior of the system is determined by many-body interactions. While thermal stability and oxidation properties as inherent material properties can be directly linked to the nanostructure of the coating, the frictional behavior of a coating cannot be generalized independent of the friction conditions.

TiO2−WO3 Photoelectrochemical Anticorrosion System with an Energy Storage Ability

Abstract: TiO2 coatings are known to protect some metals, including type 304 stainless steel, from corrosion on the basis of its reductive energy generated under UV irradiation. A TiO2 coating is coupled with a WO3 coating as an electron pool, in which the reductive energy can be stored. A WO3 film on a type 304 stainless steel plate can be charged by a UV-irradiated TiO2 coating on the same plate, in a 3 wt % NaCl aqueous solution, pH 5. The charged WO3 coating can protect the stainless steel plate from the corrosion for a while even after the UV light is turned off. Thus, the TiO2 coating protects the plate and charges the WO3 coating during the day, and the charged WO3 coating protects the plate during the night. The charge−discharge cycles are repeatable. A TiO2−WO3 composite coating also has the same effects.

Preparation of Nb2O5 Coated TiO2 Nanoporous Electrodes and Their Application in Dye-Sensitized Solar Cells

Abstract: The preparation of a new bilayer nanoporous wide band gap semiconductor electrode and its application for solar cells are reported. This new electrode consists of an inner nanoporous TiO2 matrix covered with a thin layer of ca. 2−3 nm Nb2O5. The results presented in this study show that this Nb2O5 layer forms an inherent energy barrier at the electrode−electrolyte interface. This barrier reduces the recombination rate of the photoinjected electrons with their counter holes. A comparison of two similar dye-sensitized solar cells (DSSCs) that differ only in their nanoporous electrodes shows that the solar cells made from the new electrode are superior to the standard cells with respect to all parameters. This superiority measured with many cells results in a 35% increase of the overall conversion efficiency from 3.6 to 5.0%. Optimization of the coating process and the characterization of the coating effects are described.

Quo vadis thermal spraying

Abstract: This paper is devoted to thermal spraying and presents the state of our current knowledge, as well as the following research or development needs: spraying heat sources, i.e., flame, high-velocity oxifuel flame (HVOF), detonation gun (D-Gun), and plasma torches; particle heat and momentum transfer (measurements and modeling), process on-line control, powder morphologies, and injection within the hot jet and reactions with environment; coating formation, i.e., particle flattening and solidification, splat layering, residual stresses, coating microstructure, and properties; and reliability and reproducibility of coatings.

Encapsulated chemicals for use in controlled time release applications and methods

Abstract: Encapsulated water soluble chemicals for use in controlled time release applications, methods of encapsulating the chemicals and methods of using the encapsulated chemicals are provided. The methods of encapsulating the chemicals are basically comprised of forming a first coating of a dry hydrophobic film forming material or a sparingly soluble material which provides a dry shield on the chemical and then forming a second coating of a porous cross-linked hydrophilic polymer on the first coating which prevents the substantial dissolution of the resulting encapsulated chemical for a selected period of time.

Electrodeposition and sliding wear resistance of nickel composite coatings containing micron and submicron SiC particles

Abstract: SiC particles of three different sizes, namely 5, 0.7 and 0.3 μm, were codeposited with nickel from Watts’ solutions. It was found that for a given number density of particles in the plating solution, the number density of particles in the coating increases with decreasing particle size. The friction and wear behavior of these composite coatings was evaluated in uni- and bi-directional sliding tests against corundum balls. The best sliding wear resistance was obtained with Ni–SiC composite coatings containing 4–5 vol.% submicron SiC particles.

Coatings for medical devices

Abstract: The present invention includes biocompatible coatings and films for use on implantable medical devices and medical devices containing such coatings and films applied to a surface thereof, which coatings/films are present on the device in an amount effective to provide an inert surface to be in contact with body tissue of a mammal upon implantation of the device in the mammal, and contain a film-forming polyfluoro copolymer containing the polymerized residue of a moiety selected from the group consisting of vinylidenefluoride and tetrafluoroethylene copolymerized with a second moiety other than the first moiety, wherein the relative amounts of the polymerized residue of the first and second moieties are effective to provide the coating and films with properties effective for use in coating implantable med devices.

Development and implementation of plasma sprayed nanostructured ceramic coatings

Abstract: A broad overview of the science and technology leading to the development and implementation of the first plasma sprayed nanostructured coating is described in this paper. Nanostructured alumina and titania powders were blended and reconstituted to a sprayable size. Thermal spray process diagnostics, modeling and Taguchi design of experiments were used to define the optimum plasma spray conditions to produce nanostructured alumina–titania coatings. It was found that the microstructure and properties of these coatings could be related to a critical process spray parameter (CPSP), defined as the gun power divided by the primary gas flow rate. Optimum properties were determined at intermediate values of CPSP. These conditions produce limited melting of the powder and retained nanostructure in the coatings. A broad range of mechanical properties of the nanostructured alumina–titania coatings was evaluated and compared to the Metco 130 commercial baseline. It was found that the nanostructured alumina–titania coatings exhibited superior wear resistance, adhesion, toughness and spallation resistance. The technology for plasma spraying these nanostructured coatings was transferred to the US Navy and one of their approved coating suppliers. They confirmed the superior properties of the nanostructured alumina–titania coatings and qualified them for use in a number of shipboard and submarine applications.

Heat treatable low-e coated articles and methods of making same

Abstract: A heat treatable coated article (e.g., vehicle windshield, IG unit, etc.) is provided with a dual-silver low-E coating. Before and/or after heat treatment (HT), the coating and/or coated article has a visible transmittance of at least 70%, more preferably at least 75%. Moreover, the coating and/or coated article is designed so as to have approximately the same color when viewed over a wide range of viewing angles. In certain embodiments, at least one contact layer (e.g., of or including NiCrO x ) that contacts an infrared (IR) reflecting layer (e.g., Ag) is oxidation graded so that it progressively becomes less oxidized through its thickness as it nears the IR reflecting layer. In still other embodiments, a Si-rich silicon nitride layer(s) may be utilized to reduce haze.

Coated medical devices

Abstract: An implantable medical device carries on at least part of its external surface a coating. The coating consists essentially of aterpolymer of vinyl pyrrolidone, acrylic acid and activated acrylic acid, and optionally a colouring agent.

Coated medical devices and sterilization thereof

Abstract: not available for EP1322342Abstract of corresponding document: WO0226271Medical devices, and in particular implantable medical devices, may be coated to minimize or substantially eliminate a biological organism's reaction to the introduction of the medical device to the organism. The medical devices may be coated with any number of biocompatible materials. Therapeutic drugs, agents or compounds may be mixed with the biocompatible materials and affixed to at least a portion of the medical device. These therapeutic drugs, agents or compounds may also further reduce a biological organism's reaction to the introduction of the medical device to the organism. Various materials and coating methodologies may be utilized to maintain the drugs, agents or compounds on the medical device until delivered and positioned. An efficient and effective sterilization process is also set forth.

Method for manufacturing a medical device having a coated portion by laser ablation

Abstract: The present invention is directed to a method for manufacturing a medical device having a coated portion which comprises obtaining a structure having an inner surface and an outer surface; coating at least a portion of the inner or outer surface with a first coating material; and ablating the coated tubular structure with ultrashort laser pulses to form at least one opening therein to form the coated portion. A plate can be used instead of the structure, and the plate is folded to form the structure after the ablation. A plurality of medical devices, e.g. stents, made of any materials and having uniform coating(s), can be easily manufactured by the method of the present invention.

Pharmaceutical Coating Technology

Abstract: Pharmaceutical coating technology , Pharmaceutical coating technology , کتابخانه مرکزی دانشگاه علوم پزشکی تهران

The Many Faces of Turbine Surface Roughness

Abstract: Results are presented for contact stylus measurements of surface roughness on in-service turbine blades and vanes. Nearly 100 turbine components were assembled from four land-based turbine manufacturers. Both coated and uncoated, cooled and uncooled components were measured, with part sizes varying from 2 to 20 cm. Spanwise and chordwise two-dimensional roughness profiles were taken on both pressure and suction surfaces. Statistical computations were performed on each trace to determine centerline averaged roughness, rms roughness, and peak to-valley height. In addition, skewness and kurtosis were calculated; as well as the autocorrelation length and dominant harmonics in each trace. Extensive three-dimensional surface maps made of deposits, pitting, erosion, and coating spallation expose unique features for each roughness type. Significant spatial variations are evidenced and transitions from rough to smooth surface conditions are shown to be remarkably abrupt in some cases. Film cooling sites are shown to be particularly prone to surface degradation.