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Uniform Coatings (uniform + coating)
Selected AbstractsConductive Polymer Coating on Nonconductive Ceramic Substrates for Use in the Electrophoretic Deposition ProcessJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 5 2008Tetsuo Uchikoshi Uniform coating and line patterning of a conductive polypyrrole (Ppy) film on nonconductive ceramic materials were performed for use as substrates in the electrophoretic deposition (EPD) process. The Ppy was synthesized by chemical oxidation in the pyrrole solution. Direct shaping or line patterning of alumina or zirconia particles by EPD was carried out using the Ppy films as cathodes. [source] Operating windows of slot die coating: Comparison of theoretical predictions with experimental observationsADVANCES IN POLYMER TECHNOLOGY, Issue 1 2010Chi-Feng Lin Abstract The objective of the present study is to examine the validity of the theoretical predictions on the operating windows of slot die coating. The operating window is defined as a domain inside which stable and uniform coating is possible; different types of coating defects are found outside the window. A flow visualization technique was applied to observe the coating bead, particularly the positions and shapes of the downstream and upstream menisci, just before and after coating defects appear at high coating speeds. Special features of coating bead shapes, which lead to onsets of ribbing and air entrainment, were identified. The two-dimensional flow in the coating bead region was computed by the commercial software package FLOW-3D®. Critical features observed experimentally for the onset of coating defects were used to judge whether the coating flow was within the operating window. The theoretically evaluated operating windows were found to be much larger than those determined experimentally in terms of coating speeds. However, the qualitative trends of theoretical predictions agree with experimental observations. © 2010 Wiley Periodicals, Inc. Adv Polym Techn 29:31,44, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20173 [source] Non-catalyst growth and characterization of a -plane AlGaN nanorodsPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 7 2006Mikhail E. Gaevski Abstract We report on growth of Al0.22Ga0.78N/Al0.06Ga0.94N nanorods over a -plane GaN template using low pressure metal-organic chemical vapor deposition. Nanorods with average diameter of 100 nm were up to 30 µm long. They grew preferentially along the ,110, crystal direction and possessed excellent optical and mechanical properties. It was shown using monochromatic cathodoluminescence that nanorods emit light both at 320 nm and 350 nm over entire length proving uniform coating of the Al0.06Ga0.94N rod core by an Al0.22Ga0.78N shield. The elastic modulus of nanorod material was found to be 185 GPa. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Elaboration of Monophasic and Biphasic Calcium Phosphate Coatings on Ti6Al4V Substrate by Pulsed Electrodeposition CurrentADVANCED ENGINEERING MATERIALS, Issue 6 2010Hicham Benhayoune Calcium phosphate coatings on Ti6Al4V substrates are elaborated by pulsed electrodeposition. The surface morphology and chemical composition of the coatings are characterized by SEM,EDS. The obtained results are systematically confirmed at the nanometre scale using TEM. Moreover, XRD is performed in order to identify the coatings phases. The results show that pulsed electrodeposition allows uniform coatings to be obtained without the holes and craters usually observed with classical electrodeposition. After appropriate heat treatment, these coatings have a biphasic composition of stoichiometric hydroxyapatite and , -tricalcium phosphate. Moreover, the addition of 9% H2O2 to the electrolyte leads to monophasic coatings made of stoichiometric hydroxyapatite. As an indication of the passive nature of the electrodeposited coating, electrochemical potentiodynamic tests are performed in physiological solution in order to determine the corrosion behaviour of these coatings. [source] COATING CHARACTERISTICS OF FRIED CHICKEN BREASTS PREPARED WITH DIFFERENT PARTICLE SIZE BREADINGJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2002MOHAMAD YUSOF MASKAT Characteristics of coatings formed from breading of different particle sizes were investigated in breaded, fried chicken breasts. Breading was divided into three categories namely, small (particle size , U.S. No. 60 mesh), medium (particle size between U.S. No. 20 and U.S. No. 60 mesh) and large (particle size > U.S. No. 20 mesh). Chicken breasts were battered, breaded and deep-fat fried for 240 s at 160C. Smaller breading particle size produced smoother and more uniform coatings. Compressive force at 80% strain was 14.3, 85.6 and 130.5 N for small medium and large particle size breading, respectively. With larger breading particle size, L* and a* color values increased, while b* values showed no significant change. Acoustical data taken during compression of coatings did not show any significant differences due to different breading particle sizes. [source] Pyrrole derivatives for electrochemical coating of metallic medical devicesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 7 2004Zehava Weiss Abstract Electropolymerization of medical devices such as cardiovascular stents may posses advantages including a simple and reproducible process with the ability to control the thickness, adherence, and composition of the coating by the duration and intensity of the applied current, the monomer composition and concentration, the solvent, and the reaction conditions. The properties of the polymer can also be controlled by copolymerization of different monomers, grafting substituents to a functionalized polymer, and by entrapping biomolecules. This article describes the synthesis of a range of pyrrole-based monomers and their electrocoating onto stainless steel surfaces. N-substituted pyrrole monomers with C1,C18 alkyl chains and poly (ethylene glycol) chains were synthesized in good yields and purity. Electropolymerization of these monomers provided uniform coatings with different hydrophobicities. Studies now focus on the incorporation of drugs in the coated device for release from the surface. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1658,1667, 2004 [source] Kinetics of Electrophoretic Deposition for Nanocrystalline Zinc Oxide CoatingsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2004Yuan-Chung Wang An integrated process combining the preparation of ZnO nanoparticles and the formation of ZnO coatings using electrophoretic deposition (EPD) is reported. The work focuses on the deposition kinetics of nanocrystalline ZnO coatings on copper electrodes during EPD by direct measurement of the thickness of the deposited layer. The experimental results show that the EPD process is a powerful route to fabricate uniform coatings with desired thickness and excellent surface smoothness, which might be attributed to small particle size and narrow size distribution. On the other hand, the deposition kinetics changes with applied voltage and deposition time. The deposition thickness increases with increasing applied voltage and deposition time. In a short deposition time, the deviation of deposition rate between the theoretical and experimental values is caused by voltage drops during deposition, and the discrepancy increases with the applied voltage. Moreover, the increasing voltage drop and depletion of the suspension lead to decreasing current and lower deposition rate after longer deposition time. The critical transition time of deposition kinetics is found to exponentially decrease with increasing applied voltage. [source] Atmospheric Pressure Barrier Discharge Deposition of Silica-Like Films on Polymeric SubstratesPLASMA PROCESSES AND POLYMERS, Issue S1 2007Sergei Starostine Abstract Silica-like coatings were deposited on polymer foils in APG discharge in a roll-to-roll configuration. The dependence of film structure and chemical composition on the conditions during deposition process was studied by means of SEM, ATR-FTIR, and XPS analysis. The influence of oxidant concentration on the deposited film properties is analyzed and discussed. It was observed that pulsing of the APG discharge suppresses dust formation in atmospheric plasma and, therefore, provides uniform coatings. [source] Adhesion improvement in glass fiber reinforced polyethylene composite via admicellar polymerizationPOLYMER COMPOSITES, Issue 1 2003Usa Somnuk Admicellar polymerization (polymerization of monomer solubilized in adsorbed surfactant bilayers) has been used to form a thin film of polyethylene onto the surface of milled glass fibers using sodium dodecyl sulfate as the surfactant. The decrease in ethylene pressure was used to follow the solubilization and adsolubilization processes as well as the reaction processes. An increase in initiator (Na2S2O8) to surfactant ratio gave thicker and more uniform coatings of polymer onto the glass fiber surface according to SEM micrographs. Although a substantial amount of ethylene polymerized in solution according to the pressure drop, the decrease in pressure attributed to admicelle polymerization corresponded to the amount of polymer formed on the glass fiber, indicating little, if any, solution polymer deposited on the fibers. The admicellar-treated glass fiber was used to make composites with high-density polyethylene. The composites showed an increase in tensile and flexural strength over composites made from as-received glass fiber, indicating an improvement in the fiber-matrix adhesion of the admicellar-treated glass fiber. [source] | |||||||||||||