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ENGINEERING (1208 journals)                  1 2 3 4 5 6 7 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 7)
3D Research     Hybrid Journal   (Followers: 19)
AAPG Bulletin     Hybrid Journal   (Followers: 6)
AASRI Procedia     Open Access   (Followers: 15)
Abstract and Applied Analysis     Open Access   (Followers: 3)
Aceh International Journal of Science and Technology     Open Access   (Followers: 2)
ACS Nano     Full-text available via subscription   (Followers: 229)
Acta Geotechnica     Hybrid Journal   (Followers: 7)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 2)
Acta Scientiarum. Technology     Open Access   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Active and Passive Electronic Components     Open Access   (Followers: 7)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi     Open Access  
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 6)
Advanced Science     Open Access   (Followers: 5)
Advanced Science Focus     Free   (Followers: 3)
Advanced Science Letters     Full-text available via subscription   (Followers: 7)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 7)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17)
Advances in Artificial Neural Systems     Open Access   (Followers: 4)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Complex Systems     Hybrid Journal   (Followers: 7)
Advances in Engineering Software     Hybrid Journal   (Followers: 25)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 15)
Advances in Fuzzy Systems     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 10)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 21)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 25)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
Advances in Natural Sciences: Nanoscience and Nanotechnology     Open Access   (Followers: 28)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in OptoElectronics     Open Access   (Followers: 5)
Advances in Physics Theories and Applications     Open Access   (Followers: 12)
Advances in Polymer Science     Hybrid Journal   (Followers: 41)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Remote Sensing     Open Access   (Followers: 37)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Aerobiologia     Hybrid Journal   (Followers: 1)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 4)
AIChE Journal     Hybrid Journal   (Followers: 29)
Ain Shams Engineering Journal     Open Access   (Followers: 5)
Akademik Platform Mühendislik ve Fen Bilimleri Dergisi     Open Access  
Alexandria Engineering Journal     Open Access   (Followers: 1)
AMB Express     Open Access   (Followers: 1)
American Journal of Applied Sciences     Open Access   (Followers: 28)
American Journal of Engineering and Applied Sciences     Open Access   (Followers: 11)
American Journal of Engineering Education     Open Access   (Followers: 9)
American Journal of Environmental Engineering     Open Access   (Followers: 16)
American Journal of Industrial and Business Management     Open Access   (Followers: 23)
Analele Universitatii Ovidius Constanta - Seria Chimie     Open Access  
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Regional Science     Hybrid Journal   (Followers: 7)
Annals of Science     Hybrid Journal   (Followers: 7)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applicable Analysis: An International Journal     Hybrid Journal   (Followers: 1)
Applied Catalysis A: General     Hybrid Journal   (Followers: 6)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 9)
Applied Clay Science     Hybrid Journal   (Followers: 4)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 3)
Applied Nanoscience     Open Access   (Followers: 7)
Applied Network Science     Open Access  
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 3)
Applied Sciences     Open Access   (Followers: 2)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 5)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Archives of Foundry Engineering     Open Access  
Archives of Thermodynamics     Open Access   (Followers: 7)
Arid Zone Journal of Engineering, Technology and Environment     Open Access   (Followers: 2)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 3)
Asian Engineering Review     Open Access  
Asian Journal of Applied Science and Engineering     Open Access   (Followers: 1)
Asian Journal of Applied Sciences     Open Access   (Followers: 2)
Asian Journal of Biotechnology     Open Access   (Followers: 8)
Asian Journal of Control     Hybrid Journal  
Asian Journal of Current Engineering & Maths     Open Access  
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 8)
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
ATZagenda     Hybrid Journal  
ATZextra worldwide     Hybrid Journal  
Australasian Physical & Engineering Sciences in Medicine     Hybrid Journal   (Followers: 1)
Australian Journal of Multi-Disciplinary Engineering     Full-text available via subscription   (Followers: 2)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Avances en Ciencias e Ingeniería     Open Access  
Balkan Region Conference on Engineering and Business Education     Open Access   (Followers: 1)
Bangladesh Journal of Scientific and Industrial Research     Open Access  
Basin Research     Hybrid Journal   (Followers: 4)
Batteries     Open Access   (Followers: 4)
Bautechnik     Hybrid Journal   (Followers: 1)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 23)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (Followers: 4)
BER : Manufacturing Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Motor Trade Survey     Full-text available via subscription   (Followers: 1)
BER : Retail Sector Survey     Full-text available via subscription   (Followers: 2)
BER : Retail Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Survey of Business Conditions in Manufacturing : An Executive Summary     Full-text available via subscription   (Followers: 3)
BER : Survey of Business Conditions in Retail : An Executive Summary     Full-text available via subscription   (Followers: 3)
Bharatiya Vaigyanik evam Audyogik Anusandhan Patrika (BVAAP)     Open Access   (Followers: 1)
Biofuels Engineering     Open Access  
Biointerphases     Open Access   (Followers: 1)
Biomaterials Science     Full-text available via subscription   (Followers: 9)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 5)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 17)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 32)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 8)
Biomedical Science and Engineering     Open Access   (Followers: 3)
Biomedizinische Technik - Biomedical Engineering     Hybrid Journal  
Biomicrofluidics     Open Access   (Followers: 4)
BioNanoMaterials     Hybrid Journal   (Followers: 2)
Biotechnology Progress     Hybrid Journal   (Followers: 39)
Boletin Cientifico Tecnico INIMET     Open Access  
Botswana Journal of Technology     Full-text available via subscription  
Boundary Value Problems     Open Access   (Followers: 1)
Brazilian Journal of Science and Technology     Open Access   (Followers: 2)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
Bulletin of Canadian Petroleum Geology     Full-text available via subscription   (Followers: 14)
Bulletin of Engineering Geology and the Environment     Hybrid Journal   (Followers: 3)
Bulletin of the Crimean Astrophysical Observatory     Hybrid Journal  
Cahiers, Droit, Sciences et Technologies     Open Access  
Calphad     Hybrid Journal  
Canadian Geotechnical Journal     Hybrid Journal   (Followers: 14)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 41)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 8)
Case Studies in Thermal Engineering     Open Access   (Followers: 3)
Catalysis Communications     Hybrid Journal   (Followers: 6)
Catalysis Letters     Hybrid Journal   (Followers: 2)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 8)
Catalysis Science and Technology     Free   (Followers: 6)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysis Today     Hybrid Journal   (Followers: 5)
CEAS Space Journal     Hybrid Journal  
Cellular and Molecular Neurobiology     Hybrid Journal   (Followers: 3)
Central European Journal of Engineering     Hybrid Journal   (Followers: 1)
CFD Letters     Open Access   (Followers: 6)
Chaos : An Interdisciplinary Journal of Nonlinear Science     Hybrid Journal   (Followers: 2)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Engineering     Open Access   (Followers: 2)
Chinese Science Bulletin     Open Access   (Followers: 1)
Ciencia e Ingenieria Neogranadina     Open Access  
Ciencia en su PC     Open Access   (Followers: 1)
Ciencias Holguin     Open Access   (Followers: 1)
CienciaUAT     Open Access  
Cientifica     Open Access  
CIRP Annals - Manufacturing Technology     Full-text available via subscription   (Followers: 11)
CIRP Journal of Manufacturing Science and Technology     Full-text available via subscription   (Followers: 14)
City, Culture and Society     Hybrid Journal   (Followers: 21)
Clay Minerals     Full-text available via subscription   (Followers: 9)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
Coal Science and Technology     Full-text available via subscription   (Followers: 3)
Coastal Engineering     Hybrid Journal   (Followers: 11)
Coastal Engineering Journal     Hybrid Journal   (Followers: 5)
Coatings     Open Access   (Followers: 3)
Cogent Engineering     Open Access   (Followers: 2)
Cognitive Computation     Hybrid Journal   (Followers: 4)
Color Research & Application     Hybrid Journal   (Followers: 1)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 13)
Combustion, Explosion, and Shock Waves     Hybrid Journal   (Followers: 13)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Components, Packaging and Manufacturing Technology, IEEE Transactions on     Hybrid Journal   (Followers: 26)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Composite Structures     Hybrid Journal   (Followers: 254)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 181)
Composites Part B : Engineering     Hybrid Journal   (Followers: 227)
Composites Science and Technology     Hybrid Journal   (Followers: 184)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access  
Computational Geosciences     Hybrid Journal   (Followers: 13)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 6)
Computer Science and Engineering     Open Access   (Followers: 17)
Computers & Geosciences     Hybrid Journal   (Followers: 28)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 5)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 4)
Computers and Geotechnics     Hybrid Journal   (Followers: 10)
Computing and Visualization in Science     Hybrid Journal   (Followers: 5)
Computing in Science & Engineering     Full-text available via subscription   (Followers: 30)
Conciencia Tecnologica     Open Access  
Concurrent Engineering     Hybrid Journal   (Followers: 3)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 6)
Control and Dynamic Systems     Full-text available via subscription   (Followers: 8)
Control Engineering Practice     Hybrid Journal   (Followers: 42)
Control Theory and Informatics     Open Access   (Followers: 7)
Corrosion Science     Hybrid Journal   (Followers: 25)
CT&F Ciencia, Tecnologia y Futuro     Open Access  

        1 2 3 4 5 6 7 | Last

Journal Cover Coatings
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  This is an Open Access Journal Open Access journal
   ISSN (Online) 2079-6412
   Published by MDPI Homepage  [151 journals]
  • Coatings, Vol. 7, Pages 84: Corrosion Protection of Steel by
           Epoxy-Organoclay Nanocomposite Coatings

    • Authors: Domna Merachtsaki, Panagiotis Xidas, Panagiotis Giannakoudakis, Konstantinos Triantafyllidis, Panagiotis Spathis
      First page: 84
      Abstract: The purpose of the present work was to study the corrosion behavior of steel coated with epoxy-(organo) clay nanocomposite films. The investigation was carried out using salt spray exposures, optical and scanning electron microscopy examination, open circuit potential, and electrochemical impedance measurements. The mechanical, thermomechanical, and barrier properties of pristine glassy epoxy polymer and epoxy-clay nanocomposites were examined. The degree of intercalation/exfoliation of clay nanoplatelets within the epoxy polymer also was determined. The mechanical, thermomechanical, and barrier properties of all the epoxy-clay nanocomposites were improved compared to those of the pristine epoxy polymer. In addition, both the pristine epoxy and the epoxy nanocomposite coatings protected the steel from corrosion. Furthermore, the protective properties of the nanocomposite coatings were superior compared to those of the pristine epoxy polymer. The protective properties of the nanocomposite coatings varied with the modified clay used. The epoxy-montmorillonite clay modified with primary octadecylammonium ions, Nanomer I.30E, had a better behavior than that modified with quaternary octadecylammonium ions, Nanomer I.28E.
      PubDate: 2017-06-22
      DOI: 10.3390/coatings7070084
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 85: Oxidation Behavior and Mechanism of Al4SiC4 in
           MgO-C-Al4SiC4 System

    • Authors: Huabai Yao, Xinming Xing, Enhui Wang, Bin Li, Junhong Chen, Jialin Sun, Xinmei Hou
      First page: 85
      Abstract: Al4SiC4 powder with high purity was synthesized using the powder mixture of aluminum (Al), silicon (Si), and carbon (C) at 1800 °C in argon. Their oxidation behavior and mechanism in a MgO-C-Al4SiC4 system was investigated at 1400–1600 °C. XRD, SEM, and energy dispersive spectrometry (EDS) were adopted to analyze the microstructure and phase evolution. The results showed that the composition of oxidation products was closely related to the atom diffusion velocity and the compound oxide layer was generated on Al4SiC4 surface. In addition, the effect of different CO partial pressure on the oxidation of Al4SiC4 crystals was also studied by thermodynamic calculation. This work proves the great potential of Al4SiC4 in improving the MgO-C materials.
      PubDate: 2017-06-23
      DOI: 10.3390/coatings7070085
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 86: Silica-Based Sol-Gel Coating on Magnesium
           Alloy with Green Inhibitors

    • Authors: Vinod Upadhyay, Zachary Bergseth, Brett Kelly, Dante Battocchi
      First page: 86
      Abstract: In this work, the performances of several natural organic inhibitors were investigated in a sol-gel system (applied on the magnesium alloy Mg AZ31B substrate). The inhibitors were quinaldic acid (QDA), betaine (BET), dopamine hydrochloride (DOP), and diazolidinyl urea (DZU). Thin, uniform, and defect-free sol-gel coatings were prepared with and without organic inhibitors, and applied on the Mg AZ31B substrate. SEM and EDX were performed to analyze the coating surface properties, the adhesion to the substrate, and the thickness. Electrochemical measurements, including electrochemical impedance spectroscopy (EIS) and anodic potentiodynamic polarization scan (PDS), were performed on the coated samples to characterize the coatings’ protective properties. Also, hydrogen evolution measurement—an easy method to measure magnesium corrosion—was performed in order to characterize the efficiency of coating protection on the magnesium substrate. Moreover, scanning vibrating electrode technique (SVET) measurements were performed to examine the efficiency of the coatings loaded with inhibitors in preventing and containing corrosion events in defect areas. From the testing results it was observed that the formulated sol-gel coatings provided a good barrier to the substrate, affording some protection even without the presence of inhibitors. Finally, when the inhibitors’ performances were compared, the QDA-doped sol-gel was able to contain the corrosion event at the defect.
      PubDate: 2017-06-22
      DOI: 10.3390/coatings7070086
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 87: Effect of Cold-Spray Conditions Using a
           Nitrogen Propellant Gas on AISI 316L Stainless Steel-Coating

    • Authors: Shinichiro Adachi, Nobuhiro Ueda
      First page: 87
      Abstract: Cold-spray techniques have been a significant development for depositing metal coatings in recent years. In cold-spray processes, inexpensive nitrogen gas is widely used as the propellant gas in many industries. However, it is difficult to produce austenitic stainless steel coatings with dense microstructures with cold-spray techniques when using nitrogen propellant gas because of work hardening. In this study, the effects of cold-spray conditions using a nitrogen propellant gas on AISI 316L stainless steel coatings were examined. It was found that a higher nitrogen propellant gas temperature and pressure produce coatings with dense microstructures. The measured AISI 316L coating hardness values suggest that AISI 316L particles sprayed at temperatures of 700 and 800 °C soften due to the heat, allowing uniform deformation on the substrate and consequently forming dense coating microstructures. In addition, AISI 316L powder with particle diameters of 5–20 µm resulted in a denser coating microstructure than powder with particle diameters of 10–45 and 20–53 µm. Finally, the standoff distance between the nozzle and the substrate also affected the AISI 316L coating microstructures; a standoff distance of 40 mm produced the densest microstructure.
      PubDate: 2017-06-28
      DOI: 10.3390/coatings7070087
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 88: Barrier Heights of Au on Diamond with
           Different Terminations Determined by X-ray Photoelectron Spectroscopy

    • Authors: Fengnan Li, Jingwen Zhang, Xiaoliang Wang, Minghui Zhang, Hongxing Wang
      First page: 88
      Abstract: Barrier heights of Au on hydrogen-/oxygen-/fluorine-/nitrogen-terminated diamond (H-/O-/F-/N-diamond) have been investigated by X-ray photoelectron spectroscopy. All of the H-/O-/F-/N-diamond surfaces have been formed on different areas of one diamond sample. An Au film with a thickness of 4 nm was evaporated to form Au/diamond contacts. Barrier height values for Au on H-/O-/F-/N-diamond contacts were determined to be −0.19, 1.71, 2.29, and 2.39 eV, respectively. Then, the surface of Au/diamond contacts was treated by 1000 eV Ar+ bombardment with different duration of time, resulting in a pinned barrier height of 1.83 eV independent of contact structures. In the end, the spatial distribution of the energy band diagram has been calculated by solving Poisson’s equation.
      PubDate: 2017-06-29
      DOI: 10.3390/coatings7070088
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 89: Ultra-Low Reflectivity Anti-Reflection Coating
           on a Plastic Cover Slip in Liquid for He-Ne Laser Light

    • Authors: Jin-Cherng Hsu, Heng-Ying Cho, Tsang-Yen Hsieh, Jyh-Liang Wang
      First page: 89
      Abstract: An ultra-low anti-reflection optical coating on both surfaces of a plastic cover slip was studied for use in confocal image measurements. The optical reflectance at a wavelength of 632.8 nm was less than 0.1% when the coated sample was placed in a liquid having a refractive index of 1.34, close to the aqueous solution of the biomaterial. The high- and low-index coating films, Substance-2 (PrTiO3) and silicon dioxide (SiO2), were measured by an ellipsometer to determine their optical refraction indices and extinction coefficients. Theoretically, when the two layer thicknesses are designed using the optical admittance diagram of the cover slip to approach the equivalent index of 1.34, a reflectance of 1.6 × 10−5% in the liquid could be obtained. Experimentally, the reflectance of the sample deposited on the two faces of the cover slip was 4.223 ± 0.145% as measured in the air; and 0.050 ± 0.002% as measured by a He-Ne laser in the liquid.
      PubDate: 2017-06-29
      DOI: 10.3390/coatings7070089
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 90: Concrete Damage in Field Conditions and
           Protective Sealer and Coating Systems

    • Authors: Md. Safiuddin
      First page: 90
      Abstract: Concrete structures undergo different forms of damage during their service life. The aim of this study is to identify the most common forms of concrete damage in field conditions. A number of concrete elements and structures were visually inspected and the damage was photographed. The damage phenomena covered are delamination, popout, spalling, scaling, drying shrinkage cracking, corrosion-induced cracking, map cracking, rust and salt stains, discoloration, and mold and moss growths. The probable reasons for these damage phenomena are discussed in this study. Moreover, this study highlights how concrete structures can be protected from the aforementioned forms of damage by using sealer and coating systems as surface treatments. Different sealer and coating systems, emphasizing their selection for specific uses, installation on concrete substrate, effects on concrete durability, performance criteria, and performance evaluation methods have been discussed. Furthermore, some recommendations are given to improve the performance of concrete sealer and coating systems for the protection of concrete structures in field conditions.
      PubDate: 2017-06-29
      DOI: 10.3390/coatings7070090
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 91: Application of FEM to Estimate
           Thermo-Mechanical Properties of Plasma Sprayed Composite Coatings

    • Authors: Rodolphe Bolot, Delphine Aussavy, Ghislain Montavon
      First page: 91
      Abstract: The presence of defects such as voids, inter-lamellar porosities or cracks causes a decrease in the effective thermal conductivity of plasma-sprayed coatings as well as a decrease in corresponding mechanical properties, such as the Young’s modulus. In general, the effective properties of thermal spray coatings are thus very different from that of bulk materials and thus have to be quantified to validate in service performances. A complementary approach allowing us to understand the relationships between the microstructure of a coating and its macro-properties is that of Finite Element Modeling (FEM). The case of composite coatings is more complicated still, due to the presence of different materials. In the present study, thermo-mechanical properties of a plasma-sprayed composite coating were estimated by numerical modeling based on FEM. The method applied uses directly cross-sectional micrographs without simplification, using a one-cell per pixel approach. Characteristics such as the thermal conductivity, the Young’s modulus, the Poisson’s ratio and the dilatation coefficient were considered. The example selected was an AlSi/polyester coating used as an abradable seal in the aerospace industry.
      PubDate: 2017-06-30
      DOI: 10.3390/coatings7070091
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 92: Effect of Si3N4 Addition on Oxidation
           Resistance of ZrB2-SiC Composites

    • Authors: Manab Mallik, Kalyan Ray, Rahul Mitra
      First page: 92
      Abstract: The oxidation behavior of ZrB2-20 vol % SiC and ZrB2-20 vol % SiC-5 vol % Si3N4 composites prepared by hot-pressing and subjected to isothermal exposure at 1200 or 1300 °C for durations of 24 or 100 h in air, as well as cyclic exposure at 1300 °C for 24 h, have been investigated. The oxidation resistance of the ZrB2-20 vol % SiC composite has been found to improve by around 20%–25% with addition of 5 vol % Si3N4 during isothermal or cyclic exposures at 1200 or 1300 °C. This improvement in oxidation resistance has been attributed to the formation of higher amounts of SiO2 and Si2N2O, as well as a greater amount of continuity in the oxide scale, because these phases assist in closing the pores and lower the severity of cracking by exhibiting self-healing type behavior. For both the composites, the mass changes are found to be higher during cyclic exposure at 1300 °C by about 2 times compared to that under isothermal conditions.
      PubDate: 2017-06-30
      DOI: 10.3390/coatings7070092
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 93: Investigation on the Cathodic Protection
           Effect of Low Pressure Cold Sprayed AlZn Coating in Seawater via Numerical

    • Authors: Guosheng Huang, Xiaodan Lou, Hongren Wang, Xiangbo Li, Lukuo Xing
      First page: 93
      Abstract: Cold spray can deposit a composite coating simply by spraying mechanically-mixed Al and Zn powders, while no quantitative data has been reported on the anti-corrosion performance of different composite cold-sprayed coatings. In the present work, the finite element method was used to estimate the cathodic protection effect by simulating the potential distribution on a damaged cold-sprayed AlZn coating on Q235 steel. The results indicate that AlZn coating can only provide a limiting cathodic protection for substrate, because it can only polarize a very narrow zone negative to −0.78 V (vs. SCE, saturated calomel electrode). The remaining area of the steel substrate still has a very high residual corrosion rate. Computational methods can be used to predict the corrosion rate of AlZn coating, and the simulation results were validated by the results of a weight loss experiment.
      PubDate: 2017-07-04
      DOI: 10.3390/coatings7070093
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 94: Study on the Preparation of a High-Efficiency
           Carbon Fiber Dissipating Coating

    • Authors: Jing Li, Xue Li, Chunlei Fan, Huan Yao, Xuyang Chen, Yeming Liu
      First page: 94
      Abstract: The working temperature of electronic components directly determines their service life and stability. In order to ensure normal operation of electronic components, cooling the coating is one of the best ways to solve the problem. Based on an acrylic amino-resin system, a dissipating coating was prepared with carbon fiber (CF) as the main thermal conductive filler. The influence of the CF content on the thermal conductivity was determined by the single factor method. The surface structure was observed by scanning electron microscopy (SEM). The results show: With the increase of the CF mass fraction, both the heat dispersion and heat conduction coefficient of the coating tend to increase at first and then decrease, and the heat dissipation effect is optimum when the CF mass fraction is 12.3 wt %. At this point, the coating shows an excellent comprehensive performance, such as 1st level adhesion, H grade hardness, and thermal conductivity of 1.61 W/m·K. Furthermore, this paper explored the radiating mechanism of coating in which CF produces a coating which forms a heat “channel” for rapid heat conduction. When the optimal value is exceeded, the cooling effect is reduced because of the accumulation and the anisotropy of CF.
      PubDate: 2017-07-04
      DOI: 10.3390/coatings7070094
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 95: The Effect of Deposition Parameters on the
           Growth Rate of Microcrystalline Diamond Powders Synthesized by HFCVD

    • Authors: Tao Zhang, Ye Zou
      First page: 95
      Abstract: Conventional diamond powders (<10 μm) are generally produced from crushing large-sized diamonds synthesized by high-pressure and high-temperature (HPHT) technique, whereas they have many morphological imperfections. In the present work, these powders are served as diamond seeds and regrown by hot filament chemical vapor deposition (HFCVD). Deposition parameters—such as the carbon concentration, substrate temperature, and bias current—which play a determined role in the homoepitaxial growth rate of micron diamonds, are investigated in their respective usual ranges. As shown in the experimental results, under the preconditions of maintaining the good morphology of crystals and inhibiting polycrystal growth, the growth rate of isolated diamond crystals can be controlled at 0.9 μm/h. Besides, the final improved powders have a wide range of particle sizes, which could fail to meet the requirements for commercial powders without the post-process of sieving.
      PubDate: 2017-07-06
      DOI: 10.3390/coatings7070095
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 96: Polymerization of PEDOT/PSS/Chitosan-Coated
           Electrodes for Electrochemical Bio-Sensing

    • Authors: Li Sui, Bingshu Zhang, Jun Wang, Ainan Cai
      First page: 96
      Abstract: Poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly (styrene sulfonate) (PSS) has a variety of chemical and biomedical applications. Additionally, chitosan has been extensively used in industrial and medical fields. However, whether chitosan could be incorporated into conducting polymers of PEDOT/PSS is not clear. In this study, the PEDOT/PSS/chitosan coatings were electrochemically polymerized on the surface of 0.5 mm platinum (Pt) electrodes and the properties of electrochemical cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) of the PEDOT/PSS/chitosan-coated electrodes were investigated. Furthermore, PEDOT/PSS/chitosan-coated electrodes used for electrochemical bio-sensing, using dexamethasone (Dex) as a model bio-sensing material, were examined. The results demonstrated that PEDOT/PSS/chitosan-coated electrodes were stable in phosphate-buffered saline (PBS) solution. The electrochemical CV curve areas, reflecting the charge delivery capacity, and the EIS of the PEDOT/PSS/chitosan-coated electrodes were sensitive to Dex, and the good linearity can be obtained between CV curve areas, the EIS and the concentration of Dex. In addition, electrochemical sensitivity of the PEDOT/PSS/chitosan-coated electrodes to Dex was much higher than ultraviolet (UV) spectroscopy detection. All these results revealed that the PEDOT/PSS/chitosan-coated electrodes can be electrochemical polymerized and used for electrochemical bio-sensing.
      PubDate: 2017-07-06
      DOI: 10.3390/coatings7070096
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 97: Technological Strategies to Preserve Burrata
           Cheese Quality

    • Authors: Cristina Costa, Annalisa Lucera, Amalia Conte, Angelo Zambrini, Matteo Del Nobile
      First page: 97
      Abstract: Burrata cheese is a very perishable product due to microbial proliferation and undesirable sensory changes. In this work, a step-by-step optimization approach was used to design proper processing and packaging conditions for burrata in brine. In particular, four different steps were carried out to extend its shelf life. Different headspace gas compositions (MAP-1 30:70 CO2:N2; MAP-2 50:50 CO2:N2 and MAP-3 65:35 CO2:N2) were firstly tested. To further promote product preservation, a coating was also optimized. Then, antimicrobial compounds in the filling of the burrata cheese (lysozyme and Na2-EDTA) and later in the coating (enzymatic complex and silver nanoparticles) were analyzed. To evaluate the quality of the samples, in each step headspace gas composition, microbial population, and pH and sensory attributes were monitored during storage at 8 ± 1 °C. The results highlight that the antimicrobial compounds in the stracciatella, coating with silver nanoparticles, and packaging under MAP-3 represent effective conditions to guarantee product preservation, moving burrata shelf life from three days (control sample) to ten days.
      Citation: Coatings
      PubDate: 2017-07-09
      DOI: 10.3390/coatings7070097
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 98: Influence of Process Parameters on High
           Velocity Oxy-Fuel Sprayed Cr3C2-25%NiCr Coatings

    • Authors: Mingxiang Xie, Yue Lin, Peng Ke, Shuoyu Wang, Shihong Zhang, Zhicheng Zhen, Liangshui Ge
      First page: 98
      Abstract: In this work, the Cr3C2-25% NiCr powder was deposited on stainless steel with different combustion pressures and powder feed rates using HVOF technique. The microstructure, porosity, micro-hardness, indentation fracture toughness, adhesion strength, and wear resistance at 500 °C of the coatings were investigated. The results showed that HVOF sprayed Cr3C2-25% NiCr coatings possessed low porosity, high micro-hardness, and enough adhesion strength. The powder feed rate had obvious effect on porosity, micro-hardness and indention fracture toughness of the coatings, and the coating sprayed under the powder feed rate of 33.5 g/min possessed the optimal performance. The wear tests illustrated that the HVOF sprayed Cr3C2-25NiCr coating possessed good wear resistance at the temperature of 500 °C, in which the coating sprayed at the powder feed rate of 33.5 g/min had the best wear resistance due to its dense structure and enough fracture toughness.
      Citation: Coatings
      PubDate: 2017-07-09
      DOI: 10.3390/coatings7070098
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 99: Progress in Wear Resistant Materials for Total
           Hip Arthroplasty

    • Authors: Rohit Khanna, Joo Ong, Ebru Oral, Roger Narayan
      First page: 99
      Abstract: Current trends in total hip arthroplasty (THA) are to develop novel artificial hip joints with high wear resistance and mechanical reliability with a potential to last for at least 25–30 years for both young and old active patients. Currently used artificial hip joints are mainly composed of femoral head of monolithic alumina or alumina-zirconia composites articulating against cross-linked polyethylene liner of acetabular cup or Co-Cr alloy in a self-mated configuration. However, the possibility of fracture of ceramics or its composites, PE wear debris-induced osteolysis, and hypersensitivity issue due to metal ion release cannot be eliminated. In some cases, thin ultra-hard diamond-based, TiN coatings on Ti-6A-4V or thin zirconia layer on the Zr-Nb alloy have been fabricated to develop high wear resistant bearing surfaces. However, these coatings showed poor adhesion in tribological testing. To provide high wear resistance and mechanical reliability to femoral head, a new kind of ceramic/metal artificial hip joint hybrid was recently proposed in which 10–15 μm thick dense layer of pure α-alumina was formed onto Ti-6Al-4V alloy by deposition of Al metal layer by cold spraying or cold metal transfer methods with 1–2 μm thick Al3Ti reaction layer formed at their interface to improve adhesion. An optimal micro-arc oxidation treatment transformed Al to dense α-alumina layer, which showed high Vickers hardness 1900 HV and good adhesion to the substrate. Further tribological and cytotoxicity analyses of these hybrids will determine their efficacy for potential use in THA.
      Citation: Coatings
      PubDate: 2017-07-09
      DOI: 10.3390/coatings7070099
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 100: Electrodeposition of Vanadium Oxides at Room
           Temperature as Cathodes in Lithium-Ion Batteries

    • Authors: Michalis Rasoulis, Dimitra Vernardou
      First page: 100
      Abstract: Electrodeposition of vanadium pentoxide coatings was performed at room temperature and a short growth period of 15 min based on an alkaline solution of methanol and vanadyl (III) acetyl acetonate. All samples were characterized by X-ray diffraction, Raman spectroscopy, field-emission scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The current density and electrolyte concentration were found to affect the characteristics of the as-grown coatings presenting enhanced crystallinity and porous structure at the highest values employed in both cases. The as-grown vanadium pentoxide at current density of 1.3 mA·cm−2 and electrolyte concentration of 0.5 M indicated the easiest charge transfer of Li+ across the vanadium pentoxide/electrolyte interface presenting a specific discharge capacity of 417 mAh·g−1, excellent capacitance retention of 95%, and coulombic efficiency of 94% after 1000 continuous Li+ intercalation/deintercalation scans. One may then suggest that this route is promising to prepare large area vanadium pentoxide electrodes with excellent stability and efficiency at very mild conditions.
      Citation: Coatings
      PubDate: 2017-07-12
      DOI: 10.3390/coatings7070100
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 101: Chemical Vapor Deposition of TaC/SiC on
           Graphite Tube and Its Ablation and Microstructure Studies

    • Authors: Suresh Kumar, Samar Mondal, Anil Kumar, Ashok Ranjan, Namburi Prasad
      First page: 101
      Abstract: Tantalum carbide (TaC) and silicon carbide (SiC) layers were deposited on a graphite tube using a chemical vapor deposition process. Tantalum chloride (TaCl5) was synthesized in situ by reacting tantalum chips with chlorine at 550 °C. TaC was deposited by reacting TaCl5 with CH4 in the presence of H2 at 1050–1150 °C and 50–100 mbar. SiC was deposited at 1000 °C using methyl-tri-chloro-silane as a precursor at 50 mbar. At 1150 °C; the coating thickness was found to be about 600 μm, while at 1050 °C it was about 400 μm for the cumulative deposition time of 10 h. X-ray diffraction (XRD) and X-ray Photo-Electron Spectroscopy (XPS) studies confirmed the deposition of TaC and SiC and their phases. Ablation studies of the coated specimens were carried out under oxyacetylene flame up to 120 s. The coating was found to be intact without surface cracks and with negligible erosion. The oxide phase of TaC (TaO2 and Ta2O5) and the oxide phase of SiC (SiO2) were also found on the surface, which may have protected the substrate underneath from further oxidation.
      Citation: Coatings
      PubDate: 2017-07-13
      DOI: 10.3390/coatings7070101
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 102: Ti-SLActive and TiZr-SLActive Dental Implant
           Surfaces Promote Fast Osteoblast Differentiation

    • Authors: Milena Kaluđerović, Tamara Krajnović, Danijela Maksimović-Ivanić, Hans-Ludwig Graf, Sanja Mijatović
      First page: 102
      Abstract: A primary goal in modern surface modification technology of dental implants is to achieve biocompatible surfaces with rapid but controlled healing which also allow health and longevity of implants. In order to realize all, understanding of osseointegration phenomena is crucial. Although Ti-SLA, Ti-SLActive and TiZr-SLActive surfaces have been successfully used in clinical implantology and were shown to notably reduce the primary healing time, available in vitro studies are sparse and do not concern or explore the mechanism(s) involved in human osteoblast behavior on these surfaces. Ti-SLA, Ti-SLActive, TiZr-SLActive, Ti cp, Ticer and Cercon surfaces were used. Osteoblast proliferation, cell cluster formation, morphological changes, induction of autophagy, nitric oxide (NO), reactive oxygen species/reactive nitrogen species (ROS/RNS) formation, osteocalcin (OC), bone sialoprotein (BSP) and collagen type I (Col-1) affected by various surfaces were analyzed. These surfaces induced formation of mature osteoblasts caused by elevated oxidative stress (ROS) followed by overexpression of osteoblast maturation key molecule (NO), with different intensity however. These mature osteoblasts induced upregulation of OC, BSP and Col-1, activating PI3/Akt signalling pathway resulting in autophagy, known as an important process in differentiation of osteoblast cells. Additional distinctive subpopulation identified on Ticer, Ti-SLA (after 5 days), Ti-SLActive and TiZr-SLActive surfaces (after 2 days) were forming cell clusters, essential for bone noduli formation and mineralisation. The results suggest that Ti- and TiZr-SLActive possess advanced properties in comparison with Ticer and Ti-SLA manifested as accelerated osteoblast differentiation. These effects could explain already known fast osseointegration of these surfaces in vivo.
      Citation: Coatings
      PubDate: 2017-07-15
      DOI: 10.3390/coatings7070102
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 103: Reduced-Order Modeling for and Vibration
           Characteristics Analysis of a Hard-Coated Mistuned Blisk

    • Authors: Feng Gao, Wei Sun
      First page: 103
      Abstract: This paper develops a damping strategy for the vibration reduction of a mistuned bladed disk (blisk) by depositing hard coating on its blades, and systematically investigates the vibration characteristics of the hard-coated mistuned (HCM) blisk. By using an improved fixed-interface component modal synthesis method (fixed-ICMSM), a reduced-order model (ROM) of the HCM blisk is established. Then, based on the proposed ROM, solutions of eigenvalue equations are carried out to obtain the natural frequencies and mode shapes. Further, modal loss factors and a damping matrix of the HCM blisk are achieved by taking advantage of the modal strain energy method and the proportional damping model, respectively. Moreover, the frequency response function of the HCM blisk, which can exhibit dynamic behaviors, was deduced. Finally, a mistuned blisk with a deposited NiCoCrAlY + YSZ hard coating on both sides of the blades is chosen as a study case to conduct a finite element analysis, and the results are compared with those obtained from the experimental test in terms of natural frequencies and mode shapes. The variation of the natural frequencies, the modal loss factors, and the frequency response function generated by the NiCoCrAlY + YSZ hard coating are studied, and the influence of coating area on damping capacity is further discussed.
      Citation: Coatings
      PubDate: 2017-07-18
      DOI: 10.3390/coatings7070103
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 104: Enhancing Dark Shade Pigment Dyeing of Cotton
           Fabric Using Plasma Treatment

    • Authors: Chi-Wai Kan, Wai-Shan Man
      First page: 104
      Abstract: This study is intended to investigate the effect of atmospheric pressure plasma treatment on dark shade pigment dyeing of cotton fabric. Experimental results reveal that plasma-treated cotton fabric can attain better color yield, levelness, and crocking fastness in dark shade pigment dyeing, compared with normal cotton fabric (not plasma treated). SEM analysis indicates that cracks and grooves were formed on the cotton fiber surface where the pigment and the binder can get deposited and improve the color yield, levelness, and crocking fastness. It was also noticed that pigment was aggregated when deposited on the fiber surface which could affect the final color properties.
      Citation: Coatings
      PubDate: 2017-07-19
      DOI: 10.3390/coatings7070104
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 105: Preparation of Hydroxyapatite/Tannic Acid
           Coating to Enhance the Corrosion Resistance and Cytocompatibility of AZ31
           Magnesium Alloys

    • Authors: Bowu Zhu, Shimeng Wang, Lei Wang, Yang Yang, Jun Liang, Baocheng Cao
      First page: 105
      Abstract: Hydroxyapatite/tannic acid coating (HA/TA) were prepared on AZ31 magnesium alloys (AZ31) via chemical conversion and biomimetic methods. The characterization and properties of the coating were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), corrosion testing, MC3T3-E1 cell proliferation assay, and MC3T3-E1 cell morphology observation. The results showed that tannic acid as an inducer increased the number of nucleation centers of hydroxyapatite and rendered the morphology more uniform. Compared to bare AZ31 magnesium (Mg) alloys (Ecorr = −1.462 ± 0.006 V, Icorr = (4.8978 ± 0.2455) × 10−6 A/cm2), the corrosion current density of the HA/TA-coated magnesium alloys ((5.6494 ± 0.3187) × 10−8 A/cm2) decreased two orders of magnitude, and the corrosion potential of the HA/TA-coated Mg alloys (Ecorr = −1.304 ± 0.006 V) increased by about 158 mV. This indicated that the HA/TA coating was effectively protecting the AZ31 against corrosion in simulated body fluid (SBF). Cell proliferation assays and cell morphology observations results showed that the HA/TA coating was not toxic to the MC3T3-E1 cells.
      Citation: Coatings
      PubDate: 2017-07-20
      DOI: 10.3390/coatings7070105
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 106: Particle Characterisation and Depletion of
           Li2CO3 Inhibitor in a Polyurethane Coating

    • Authors: Anthony Hughes, James Laird, Chris Ryan, Peter Visser, Herman Terryn, Arjan Mol
      First page: 106
      Abstract: The distribution and chemical composition of inorganic components of a corrosion-inhibiting primer based on polyurethane is determined using a range of characterisation techniques. The primer consists of a Li2CO3 inhibitor phase, along with other inorganic phases including TiO2, BaSO4 and Mg-(hydr)oxide. The characterisation techniques included particle induced X-ray and γ-ray emission spectroscopies (PIXE and PIGE, respectively) on a nuclear microprobe, as well as SEM/EDS hyperspectral mapping. Of the techniques used, only PIGE was able to directly map the Li distribution, although the distribution of Li2CO3 particles could be inferred from SEM through using backscatter contrast and EDS. Characterisation was also performed on a primer coating that had undergone leaching in a neutral salt spray test for 500 h. Overall, it was found that Li2CO3 leaching resulted in a uniform depletion zone near the surface, but also much deeper local depletion, which is thought to be due to the dissolution of clusters of Li2CO3 particles that were connected to the external surface/electrolyte interface.
      Citation: Coatings
      PubDate: 2017-07-21
      DOI: 10.3390/coatings7070106
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 107: The Dispersion Tolerance of Micro/Nano
           Particle in Polydimethylsiloxane and Its Influence on the Properties of
           Fouling Release Coatings Based on Polydimethylsiloxane

    • Authors: Miao Ba, Zhanping Zhang, Yuhong Qi
      First page: 107
      Abstract: Particles can be used to improve the mechanical properties of fouling release coatings based on polydimethylsiloxane (PDMS). In this study, coatings were prepared by high speed stirring using seven types of particles, with different particle size from nanometer to micrometer. The influence of specific surface area of the particles on the dispersion tolerance was investigated. The results showed that the dispersion tolerance of particles in PDMS decreased with the increase in specific surface area of the particle, and for nano particles, the factor most affecting the dispersion tolerance was the specific surface area of agglomerate particle. Subsequently, the surface properties, mechanical properties, and biofilm adhesion assay of coatings were investigated. Results indicated that surface roughness increased with the increase of dispersion tolerance. Surface roughness of samples improved the hydrophobicity of samples, yet the polar chemical group of nano silica and fumed silica reduced the hydrophobicity of samples. Further, particles could enhance the mechanical properties of coating, especially nano particles. Compared to the coating without particle, biofilm adhesion performance of coating with particles decreased, which was determined by the increase of the elastic modulus and surface roughness of coatings.
      Citation: Coatings
      PubDate: 2017-07-21
      DOI: 10.3390/coatings7070107
      Issue No: Vol. 7, No. 7 (2017)
  • Coatings, Vol. 7, Pages 72: Ammonia Generation via a Graphene-Coated
           Nickel Catalyst

    • Authors: Fei Lu, Gerardine Botte
      First page: 72
      Abstract: A novel graphene-coated Ni electrode was developed in this investigation to improve corrosion resistance while unexpectedly enhancing the ammonia generation rate in the electrochemically induced urea to ammonia (eU2A) process, which is an electrochemical onsite ammonia generation method. The development of the electrode is crucial for the eU2A reactions since in the ammonia generation process, the concentration of ammonia is inevitably high on the surface of the electrode, leading to severe corrosion of the electrode and the loss of generated ammonia as well. In this paper, the graphene was derived from raw coal by using the chemical vapor deposition method and self-lifted onto a Ni electrode to form a protective layer for corrosion prevention. Transmission electron microscopy showed the synthesized graphene had few-layers and Raman spectroscopy indicated that the coating of graphene was stable during the eU2A reaction. As a result, the ammonia corrosion of the Ni electrode was dramatically reduced by ~20 times with the graphene coating method. More importantly, a higher ammonia generation rate (~2 times) was achieved using the graphene-coated Ni working electrode compared to a bare Ni electrode in the eU2A process.
      PubDate: 2017-05-27
      DOI: 10.3390/coatings7060072
      Issue No: Vol. 7, No. 6 (2017)
  • Coatings, Vol. 7, Pages 73: Combustion Synthesis of UHTC Composites from
           Ti–B4C Solid State Reaction with Addition of VIb Transition Metals

    • Authors: Chun-Liang Yeh, Wei-Zuo Lin
      First page: 73
      Abstract: UHTC composites were prepared by self-propagating high-temperature synthesis (SHS) from the Ti–B4C reaction system with addition of Cr, Mo, and W. The starting sample composition was formulated as (3−x)Ti + B4C + xMe with x = 0.1–1.0 and Me = Cr, Mo, or W. For all samples conducted in this study, self-sustaining combustion was well established and propagated with a distinct reaction front. With no addition of Cr, Mo, or W, solid state combustion of the 3Ti + B4C sample featuring a combustion front temperature (Tc) of 1766 °C and a combustion wave velocity (Vf) of 16.5 mm/s was highly exothermic and produced an in situ composite of 2TiB2 + TiC. When Cr, Mo, or W was adopted to replace a portion of Ti, the reaction exothermicity was lowered, and hence, a significant decrease in Tc (from 1720 to 1390 °C) and Vf (from 16.1 to 3.9 mm/s) was observed. With addition of Cr, Mo, and W, the final products were CrB-, MoB-, and WB-added TiB2–TiC composites. The absence of CrB2, MoB2, and WB2 was attributed partly to the loss of boron from thermal decomposition of B4C and partly to lack of sufficient reaction time inherent to the SHS process.
      PubDate: 2017-06-01
      DOI: 10.3390/coatings7060073
      Issue No: Vol. 7, No. 6 (2017)
  • Coatings, Vol. 7, Pages 74: Fabrication of Luminescent Antireflective
           Coatings with CaMoO4:Eu3+/Ag Composite Structure

    • Authors: Kazuhiro Matsumoto, Manabu Hagiwara, Shinobu Fujihara
      First page: 74
      Abstract: Highly transparent and luminescent CaMoO4:Eu3+/Ag composite films were fabricated on glass substrates as multifunctional antireflective (AR) coatings. The films were deposited through a combination of a sol–gel dip-coating technique and a hot water treatment. With the addition of an aluminum source in coating solutions, the sol–gel-derived films underwent a remarkable microstructural change during the hot water treatment due to the reaction between an amorphous alumina phase and water. This change brought both an antireflective effect (suppression of Fresnel reflection) and luminescence enhancement (suppression of total internal reflection) to the films. The introduction of Ag nanoparticles into the films further increased luminescence intensity without losing the antireflective effect.
      PubDate: 2017-06-02
      DOI: 10.3390/coatings7060074
      Issue No: Vol. 7, No. 6 (2017)
  • Coatings, Vol. 7, Pages 75: Surface Erosion of Low-Current Reed Switches

    • Authors: Igor Zeltser, Aleksey Karpov, Evgeny Moos, Nikolay Rybin, Alexander Tolstoguzov
      First page: 75
      Abstract: The erosion model of the surface coatings of reed switches considering different physicochemical processes occurring on the contact surfaces and inside the inter-electrode gap was proposed. According to that, the discrete electron avalanche (ecton) introduced in the explosive electron emission theory by Mesyats is considered as the main motive force responsible for the surface modification and mass transfer of materials in the course of breaking/shorting of the contacts. By means of SEM imaging and energy dispersive X-ray microanalysis of the contact surfaces after various numbers of switching cycles, the energy threshold of the ecton generation defining the erosion stability of the coatings was found to be proportional to the specific sublimation and ionization energies of coating materials. It has been shown that the total erosion of the coatings on the working surface of the contacts after the commutation test possess the resultant character; i.e., the specificities of erosion occurring after each commutation event are characteristic for the whole of the commutation test. In further development of our model, we suggested that a few monolayers of metals (or alloys) with low ionization potential deposited on the main coatings can improve the erosion stability of contacts.
      PubDate: 2017-06-03
      DOI: 10.3390/coatings7060075
      Issue No: Vol. 7, No. 6 (2017)
  • Coatings, Vol. 7, Pages 76: Alternative Fillers for the Production of
           Bituminous Mixtures: A Screening Investigation on Waste Powders

    • Authors: Cesare Sangiorgi, Piergiorgio Tataranni, Francesco Mazzotta, Andrea Simone, Valeria Vignali, Claudio Lantieri
      First page: 76
      Abstract: There has been a significant increase in the demand for using recycled materials in construction because of the lack and limitation of available natural resources. A number of industrial and domestic waste products are being used in the replacement of traditional materials for road construction, and many studies have been carried out in recent years on the use of different recycled materials in substitution of conventional fillers in Asphalt Concretes (AC). The aim of this laboratory research is to analyze the physical characteristics of three different recycled fillers and compare them with those of a traditional limestone filler. The alternative fillers presented in this paper are: a waste bleaching clay that comes from two consecutive stages in the industrial process for decolouring vegetable oils and producing biogas (Ud filler), a dried mud waste from a tungsten mine (MW filler) and a recycled glass powder (Gl filler). Results show significant differences between the fillers, and, in particular, Rigden Voids (RV) seem to have the largest potential influence on the rheology of ACs.
      PubDate: 2017-06-03
      DOI: 10.3390/coatings7060076
      Issue No: Vol. 7, No. 6 (2017)
  • Coatings, Vol. 7, Pages 77: Optimization of the Laser Hardening Process by
           Adapting the Intensity Distribution to Generate a Top-hat Temperature
           Distribution Using Freeform Optics

    • Authors: Fritz Klocke, Martin Schulz, Stefan Gräfe
      First page: 77
      Abstract: Laser hardening is a surface hardening process which enables high quality results due to the controllability of the energy input. The hardened area is determined by the heat distribution caused by the intensity profile of the laser beam. However, commonly used top-hat laser beams do not provide an ideal temperature profile. Therefore, in this paper the beam profile, and thus the temperature profile, is optimized using freeform optics. The intensity distribution is modified to generate a top-hat temperature profile on the surface. The results of laser hardening with the optimized distribution are thereupon compared with results using a top-hat intensity distribution.
      PubDate: 2017-06-07
      DOI: 10.3390/coatings7060077
      Issue No: Vol. 7, No. 6 (2017)
  • Coatings, Vol. 7, Pages 78: Mn-Promoted Growth and Photoluminescence of
           Molybdenum Disulphide Monolayer

    • Authors: Shengzhong Jin, Shichao Zhao, Jiaxin Weng, Yanfei Lv
      First page: 78
      Abstract: Molybdenum disulphide (MoS2) monolayer is a two-dimensional semiconductor material with potential applications in nano electronic devices. However, it is still a challenge to reproducibly synthesize single layer MoS2 in high quality. Herein, we report the growth of monolayer of MoS2 on the SiO2/Si substrate with manganese heterogeneous nucleation. It was shown that the Mn promotes the growth of monolayer MoS2 via heterogeneous nucleation. The growth temperature range expanded two-fold, the nucleation density increased as well. The monolayer prepared in the presence of Mn exhibits a unique red emission peak at 732 nm at room temperature compared to the sample in the absence of Mn.
      PubDate: 2017-06-08
      DOI: 10.3390/coatings7060078
      Issue No: Vol. 7, No. 6 (2017)
  • Coatings, Vol. 7, Pages 79: Nitrogen Trapping Ability of Hydrogen-Induced
           Vacancy and the Effect on the Formation of AlN in Aluminum

    • Authors: Duy Vo, Aleksey Lipnitskii, Truong Nguyen, Thoi Nguyen
      First page: 79
      Abstract: This paper presents the ternary interaction of N, H, and vacancy point defects and the nitrogen trapping ability of aluminum vacancies induced by hydrogen by means of DFT methods employed in VASP (Vienna Ab initio Simulation Package) and Abinit packages. The obtained vacancy formation energy of 0.65 eV is close to experimental values. Although the N–vacancy complex is unstable with the negative binding energy of −0.51 eV, the stability of H–vacancy–N is proved by the positive binding energy of 0.59 eV and the appearance of the orbital hybridization in the density of state (DOS) of atoms connecting to this complex. Moreover, Al vacancies can trap more than 4 N atoms, which prevents the formation of aluminum nitride and subsequently affects not only the hardness of the Al surface but also many practical applications of AlN coating.
      PubDate: 2017-06-09
      DOI: 10.3390/coatings7060079
      Issue No: Vol. 7, No. 6 (2017)
  • Coatings, Vol. 7, Pages 80: Development of a TiC/Cr23C6 Composite Coating
           on a 304 Stainless Steel Substrate through a Tungsten Inert Gas Process

    • Authors: Behzad Heidarshenas, Ghulam Hussain, Mohammed. Asmael
      First page: 80
      Abstract: The aim of this study was to develop a composite coating on 304 stainless steel employing a TIG (tungsten inert gas) process. Ti wire cored with graphite powder was used as the means of coating material. The process parameters were controlled to develop a coating with optimum characteristics (i.e., hardness and wear resistance). The microstructure of the coating was analyzed with SEM and XRD. It was found that both the hardness and the wear resistance increase as the current increases, while both of these properties decrease as travelling speed increases. It was found that the coated samples with composite layers were harder than the substrate and can range up to 1100 HV, almost 4.5 times higher than the hardness of 304 stainless steel. Likewise, the wear resistance of the coating was observed to be 4.5 times higher than that of the substrate. The high performance of the coating, as revealed by microstructural analysis, was due to the formation of TiC and Cr23C6.The optimum conditions for producing the coating are thus proposed to include a 120 A current and a 3.17 mm/s travel speed.
      PubDate: 2017-06-14
      DOI: 10.3390/coatings7060080
      Issue No: Vol. 7, No. 6 (2017)
  • Coatings, Vol. 7, Pages 81: Maximum Deformation Ratio of Droplets of
           Water-Based Paint Impact on a Flat Surface

    • Authors: Weiwei Xu, Jianfei Luo, Jun Qin, Yongming Zhang
      First page: 81
      Abstract: In this research, the maximum deformation ratio of water-based paint droplets impacting and spreading onto a flat solid surface was investigated numerically based on the Navier–Stokes equation coupled with the level set method. The effects of droplet size, impact velocity, and equilibrium contact angle are taken into account. The maximum deformation ratio increases as droplet size and impact velocity increase, and can scale as We1/4, where We is the Weber number, for the case of the effect of the droplet size. Finally, the effect of equilibrium contact angle is investigated, and the result shows that spreading radius decreases with the increase in equilibrium contact angle, whereas the height increases. When the dimensionless time t* < 0.3, there is a linear relationship between the dimensionless spreading radius and the dimensionless time to the 1/2 power. For the case of 80° ≤ θe ≤ 120°, where θe is the equilibrium contact angle, the simulation result of the maximum deformation ratio follows the fitting result. The research on the maximum deformation ratio of water-based paint is useful for water-based paint applications in the automobile industry, as well as in the biomedical industry and the real estate industry. Please check all the part in the whole passage that highlighted in blue whether retains meaning before.
      PubDate: 2017-06-19
      DOI: 10.3390/coatings7060081
      Issue No: Vol. 7, No. 6 (2017)
  • Coatings, Vol. 7, Pages 82: Functionalized Textile Based Therapy for the
           Treatment of Atopic Dermatitis

    • Authors: Wenyi Wang, Patrick Hui, Chi-Wai Kan
      First page: 82
      Abstract: Atopic dermatitis (AD) is a common chronic inflammatory skin condition characterized by intense puritus and skin dryness. The pathogenesis for AD has not been fully understood to date. Complementary therapies are very popular as effective treatment for AD among clinical practitioners. This study presents a comprehensive review of published works associated with textiles-based complementary therapies for AD treatment such as wet-wrap dressing, functionalized textiles, and the application of hydrogel techniques in the textile industry to provide a better understanding of the development and design of new textiles-based transdermal therapies.
      PubDate: 2017-06-17
      DOI: 10.3390/coatings7060082
      Issue No: Vol. 7, No. 6 (2017)
  • Coatings, Vol. 7, Pages 83: Aluminizing via Ionic Liquid Electrodeposition
           and Pack Cementation: A Comparative Study with Inconel 738 and a CoNiCrAlY

    • Authors: Luca Tagliaferri, Enrico Berretti, Andrea Giaccherini, Stefano M. Martinuzzi, Francesco Bozza, Martin Thoma, Ugo Bardi, Stefano Caporali
      First page: 83
      Abstract: A novel aluminizing process based upon room temperature Al-electrodeposition from Ionic Liquids followed by diffusion heat treatment was applied on bare- and CoNiCrAlY-coated Inconel 738 (IN738). The aluminized samples were tested by isothermal oxidation at 1000 °C in air. The microstructural and chemical evolution of the samples were determined as function of oxidation time and compared with the currently applied coatings obtained via pack cementation. The newly proposed method is suitable for the CoNiCrAlY coating, but not for the bare IN738. In the latter, the formed Al-enriched layer is much thinner and the anticorrosion properties resulted in being reduced. This is probably due to the presence of precipitates, which slow down the aluminum inward diffusion impairing the formation of a well-developed interdiffusion zone (IDZ). Traces of the electrolyte, embedded during the Al-electrodeposition process, can be seen as the origin of these precipitates.
      PubDate: 2017-06-19
      DOI: 10.3390/coatings7060083
      Issue No: Vol. 7, No. 6 (2017)
  • Coatings, Vol. 7, Pages 57: Theoretical Studies of the Adsorption and
           Migration Behavior of Boron Atoms on Hydrogen-Terminated Diamond (001)

    • Authors: Xuejie Liu, Congjie Kang, Haimao Qiao, Yuan Ren, Xin Tan, Shiyang Sun
      First page: 57
      Abstract: The adsorption and migration activation energies of boron atoms on a hydrogen-terminated diamond (001) surface were calculated using first principles methods based on density functional theory. The values were then used to investigate the behavior of boron atoms in the deposition process of B-doped diamond film. On the fully hydrogen-terminated surface, the adsorption energy of a boron atom is relatively low and the maximum value is 1.387 eV. However, on the hydrogen-terminated surface with one open radical site or two open radical sites, the adsorption energy of a boron atom increases to 4.37 eV, and even up to 5.94 eV, thereby forming a stable configuration. When a boron atom deposits nearby a radical site, it can abstract a hydrogen atom from a surface carbon atom, and then form a BH radical and create a new radical site. This study showed that the number and distribution of open radical sites, namely, the adsorption of hydrogen atoms and the abstraction of surface hydrogen atoms, can influence the adsorption and migration of boron atoms on hydrogen-terminated diamond surfaces.
      PubDate: 2017-04-27
      DOI: 10.3390/coatings7050057
      Issue No: Vol. 7, No. 5 (2017)
  • Coatings, Vol. 7, Pages 58: Field Evaluation of Red-Coloured Hot Mix
           Asphalt Pavements for Bus Rapid Transit Lanes in Ontario, Canada

    • Authors: Qingfan Liu, Sina Varamini, Susan Tighe
      First page: 58
      Abstract: Coloured pavements have been implemented by metropolitan areas to denote dedicated lanes for bus rapid transit to maintain a high level of safety. Transit benefits of these installations are well documented. However, field performance of various types of coloured pavement has not been investigated systematically, with questions not being answered. In collaboration with the Regional Municipality of York (ON, Canada) where red pavement sections have been in operation for years for its bus rapid transit lanes, the Centre for Pavement and Transportation Technology at the University of Waterloo (Waterloo, ON, Canada) assessed the performance of various types of red pavements including epoxy paint and red asphalt mixes. It was found that, with significant lower texture depth, epoxy paint surface has disadvantages to red asphalt pavement from a pavement texture and safety perspective. The red asphalt sections in this study were observed as lower yet compatible frictional levels to conventional black pavement. Various types of contamination onto the red pavement were observed during field survey. In addition, the ultraviolet radiation degraded the colour of red asphalt pavement over time and may make it less effective for lane designation. Long-term monitoring is recommended to evaluate the functional and structural performance of red asphalt pavement.
      PubDate: 2017-04-26
      DOI: 10.3390/coatings7050058
      Issue No: Vol. 7, No. 5 (2017)
  • Coatings, Vol. 7, Pages 59: Ride Quality Due to Road Surface
           Irregularities: Comparison of Different Methods Applied on a Set of Real
           Road Profiles

    • Authors: Giuseppe Loprencipe, Pablo Zoccali
      First page: 59
      Abstract: Road roughness evaluation can be carried out using different approaches. Among these, the assessment of ride quality level perceived by road users is one of the most-used. In this sense, different evaluation methods have been developed in order to link the level of irregularities present on road surface profiles with the induced detrimental effects in terms of discomfort. In particular, relationships between wavelength content of road profiles and consequent level of comfort perceived had been investigated by using, in general, a mean panel ratings approach. In this paper, four ride quality evaluation methods (Ride Number, Michigan Ride Quality Index (RQI), Minnesota Ride Quality Index and frequency-weighted vertical acceleration, awz, according to ISO 2631 were applied to a set of real road profiles. The obtained results were analyzed, investigating a possible relation between the different indices, comparing them also with the most-used road roughness method worldwide: the International Roughness Index (IRI). The analyses carried out in this work have highlighted how the various rating scales may lead to a different ride quality assessment of the same road pavements. Furthermore, comparing the awz with the values obtained for the other three methods, it was found that their rating scales are set for speeds within the range 80–100 km/h. For this reason, it is necessary to identify new thresholds to be applied for lower speeds, as in the case of urban roads. In this sense, the use of the ISO 2631 approach would seem to be a useful tool.
      PubDate: 2017-04-26
      DOI: 10.3390/coatings7050059
      Issue No: Vol. 7, No. 5 (2017)
  • Coatings, Vol. 7, Pages 60: Water and Oil Repellent Finishing of Textiles

    • Authors: Franco Ferrero, Monica Periolatto, Lorenzo Tempestini
      First page: 60
      Abstract: In this work, various textile fabrics were coated with silicone and fluorocarbon-based resins by photo-curing using ultraviolet irradiation. A great number of large fabric samples were impregnated by padding with commercial finishing agents and then irradiated in air with a high power, semi-industrial UV source. The add-on of various finishing agents was kept low to reduce the treatment cost. White and dyed samples of different textile composition were treated and evaluated in terms of conferred repellency, yellowing, or color changes. Most relevant process parameters were investigated, utilizing the thermal process normally adopted at industrial level as reference. The results were statistically evaluated by ANOVA using Minitab 16 software, in order to identify the most influential parameters and to evaluate the real possibility of replacing the thermal treatment with UV curing.
      PubDate: 2017-04-26
      DOI: 10.3390/coatings7050060
      Issue No: Vol. 7, No. 5 (2017)
  • Coatings, Vol. 7, Pages 61: Kinetic Analysis of Additive on Plasma
           Electrolytic Boriding

    • Authors: Yongfeng Jiang, Yefeng Bao, Min Wang
      First page: 61
      Abstract: Plasma electrolytic boriding (PEB) is a method of combination surface strengthening and surface texturing on metal. In this study, the kinetics and the lubrication friction of borided layers in the plasma electrolytic boriding on the Q235 were investigated in an aqueous solution for 5–15 min. The cross-section and surface morphologies of the boriding layers were confirmed using scanning electron microscope (SEM). The presence of phases on the surface was determined using the X-ray diffraction. The hardness and the lubrication friction were evaluated using a micro-hardness tester and pin-on-disk friction tester in an oil sliding condition, respectively. The PEB layer contains phases in FeB, Fe2B, Ni3B4, NiB, and Ni2B. It is indicated that the value of activation energy in the PEB treatment is approximately 186.17 kJ/mol. The random micro-pores in surface texturing are unevenly distributed on the surface of the Q235. The micro-hardness of the boriding layer is up to 900 HV, whereas that of the substrate is approximately 181 HV. The weight loss of PEB sample in 10 min is 0.0017 mg in the lubrication friction, whereas that of untreated sample is 0.0047 mg in the same condition. The formation of boriding strengthening surface texturing in PEB improves lubrication friction greatly.
      PubDate: 2017-04-28
      DOI: 10.3390/coatings7050061
      Issue No: Vol. 7, No. 5 (2017)
  • Coatings, Vol. 7, Pages 62: An All Sol-Gel Process for the Heteroepitaxial
           Growth of YBa2Cu3O7−x/LaNiO3/YBa2Cu3O7−x Tri-layer

    • Authors: Chuanbao Wu, Gaoyang Zhao, Po Fang, Shasha Wang, Ye Zhang
      First page: 62
      Abstract: The preparation of a YBa2Cu3O7−x/LaNiO3/YBa2Cu3O7−x sandwich structured film on a LaAlO3 (100) substrate by a sol-gel method was investigated. YBa2Cu3O7−x/LaNiO3/YBa2Cu3O7−x tri-layer heterostructures with different epitaxial characteristics can be deposited by controlling the heat treatment temperature. X-ray diffraction and transmission electron microscopy results show that the bottom YBCO film grows epitaxially on the LaAlO3 substrate along the c axis, and that this epitaxial growth trend is extended to the subsequently deposited LaNiO3 film. For this reason, the LaNiO3 film also grows epitaxially along the c axis. Furthermore, this epitaxial growth trend is extended to the top YBa2Cu3O7−x film, yielding YBa2Cu3O7−x/LaNiO3/YBa2Cu3O7−x tri-layer heterostructures with epitaxial growth characteristics along the c axis, which enables both the bottom and top YBa2Cu3O7−x layers to possess superconducting abilities.
      PubDate: 2017-04-28
      DOI: 10.3390/coatings7050062
      Issue No: Vol. 7, No. 5 (2017)
  • Coatings, Vol. 7, Pages 63: Fabrication of Photovoltaic Textiles

    • Authors: Robert Mather, John Wilson
      First page: 63
      Abstract: Solar photovoltaic (PV) arrays are providing an increasing fraction of global electrical demand, with an accelerating rate of new installations. Most of these employ conventional glass-fronted panels, but this type of PV array does not satisfy applications that require a light-weight, flexible PV generator. An option discussed in this article is to consider textiles for such solar cell substrates. As explained in this review, combining the choice of PV cell type with the choice of textile offers alternative structures for flexible PV cells. In particular, the relative advantages and disadvantages are contrasted, either forming PV-coated fibres into a fabric, or coating an already formed fabric with the PV materials. It is shown that combining thin-film amorphous silicon PV technology and woven polyester fabric offers one solution to realizing flexible fabric PV cells, using well-understood coating methods from the textile and semiconductor industries. Finally a few applications are presented that are addressed by this approach.
      PubDate: 2017-04-29
      DOI: 10.3390/coatings7050063
      Issue No: Vol. 7, No. 5 (2017)
  • Coatings, Vol. 7, Pages 64: Strain Effects by Surface Oxidation of Cu3N
           Thin Films Deposited by DC Magnetron Sputtering

    • Authors: Abhijit Majumdar, Steffen Drache, Harm Wulff, Arun Mukhopadhyay, Satyaranjan Bhattacharyya, Christiane Helm, Rainer Hippler
      First page: 64
      Abstract: We report the self-buckling (or peeling off) of cubic Cu3N films deposited by DC magnetron sputtering of a Cu target in a nitrogen environment at a gas pressure of 1 Pa. The deposited layer partially peels off as it is exposed to ambient air at atmospheric pressure, but still adheres to the substrate. The chemical composition of the thin film as investigated by means of X-ray photoelectron spectroscopy (XPS) shows a considerable surface oxidation after exposure to ambient air. Grazing incidence X-ray diffraction (GIXRD) confirms the formation of a crystalline Cu3N phase of the quenched film. Notable are the peak shifts in the deposited film to smaller angles in comparison to stress-free reference material. The X-ray pattern of Cu3N exhibits clear differences in the integral width of the line profiles. Changes in the film microstructure are revealed by X-ray diffraction, making use of X-ray line broadening (Williamson–Hall and Stokes–Fourier/Warren–Averbach method); it indicates that the crystallites are anisotropic in shape and show remarkable stress and micro-strain.
      PubDate: 2017-04-29
      DOI: 10.3390/coatings7050064
      Issue No: Vol. 7, No. 5 (2017)
  • Coatings, Vol. 7, Pages 65: A Specified Procedure for Distress
           Identification and Assessment for Urban Road Surfaces Based on PCI

    • Authors: Giuseppe Loprencipe, Antonio Pantuso
      First page: 65
      Abstract: In this paper, a simplified procedure for the assessment of pavement structural integrity and the level of service for urban road surfaces is presented. A sample of 109 Asphalt Concrete (AC) urban pavements of an Italian road network was considered to validate the methodology. As part of this research, the most recurrent defects, those never encountered and those not defined with respect to the list collected in the ASTM D6433 have been determined by statistical analysis. The goal of this research is the improvement of the ASTM D6433 Distress Identification Catalogue to be adapted to urban road surfaces. The presented methodology includes the implementation of a Visual Basic for Application (VBA) language-based program for the computerization of Pavement Condition Index (PCI) calculation with interpolation by the parametric cubic spline of all of the density/deduct value curves of ASTM D6433 distress types. Also, two new distress definitions (for manholes and for tree roots) and new density/deduct curve values were proposed to achieve a new distress identification manual for urban road pavements. To validate the presented methodology, for the 109 urban pavements considered, the PCI was calculated using the new distress catalogue and using the ASTM D6433 implemented on PAVERTM. The results of the linear regression between them and their statistical parameters are presented in this paper. The comparison of the results shows that the proposed method is suitable for the identification and assessment of observed distress in urban pavement surfaces at the PCI-based scale.
      PubDate: 2017-04-30
      DOI: 10.3390/coatings7050065
      Issue No: Vol. 7, No. 5 (2017)
  • Coatings, Vol. 7, Pages 66: Fatigue and Healing Properties of Low
           Environmental Impact Rubberized Bitumen for Asphalt Pavement

    • Authors: Ayad Subhy, Davide Lo Presti
      First page: 66
      Abstract: The addition of recycled tyre rubber as a modifier to enhance the mechanical properties of bitumen has proven to provide asphalt mixtures with better mechanical performance. However the rubberised bitumen presents the limitation of requiring higher manufacturing and compaction temperatures. This could be solved by subjecting the tyre rubber to sort of pre-treatments such as: Adding warm-mix additives and/or using partial devulcanisation. These solutions have the potential of lowering the overall environmental impact of the asphalt pavement, however it is still not clear whether these can be detrimental for the rubberized asphalt binder mechanical properties. This paper investigates the effect on fatigue and healing properties of rubberized bitumen blended with pre-treated crumb rubber. An innovative combined fatigue and healing analysis will be presented and used to compare the several rubberised binders with a neat bitumen. The analysis consists in conducting time sweep tests by means of dynamic shear rheometer, by applying repeated cycles of stress or strain loading at selected temperatures and loading frequency. The healing potential of binders was evaluated by introducing short rest periods after a certain number of load pulses. At last, the unique energy parameter obtained using the Ratio of Dissipated Energy Change approach, was applied to obtain a unique index that could provide combined information for both fatigue binder damage and healing phenomenon. The results showed that the analysed rubberised bitumens show having better fatigue and healing performance when compared to the straight-run bitumen.
      PubDate: 2017-05-05
      DOI: 10.3390/coatings7050066
      Issue No: Vol. 7, No. 5 (2017)
  • Coatings, Vol. 7, Pages 67: Characterization of the Anti-Graffiti
           Properties of Powder Organic Coatings Applied in Train Field

    • Authors: Stefano Rossi, Michele Fedel, Simone Petrolli, Flavio Deflorian
      First page: 67
      Abstract: The widespread prevalence of the phenomenon of graffiti and the growth of the removal cost—in particular in public transport systems—has pushed the research for technical solutions to this problem. Suitable solutions to address graffiti-related concerns are needed in order to reduce the cleaning costs as well as the downtime of trains. Graffiti are a big problem for painted metal, because the protective coatings and graffiti have the same chemical nature (polymeric matter). A permanent coating is expected to be able to resist the highest possible number of cleanings of the graffiti without modifying its aesthetic and corrosion protection properties. The purpose of this study is to develop a methodological approach for the characterization of graffiti-resistant organic coatings. For this purpose, a critical review of the existing standards is carried out. The anti-graffiti properties of a polyurethane organic coating were investigated before and after accelerated weathering. In order to understand the behavior of the coatings during cleaning, the aging of the coating in contact with the remover was carried out. The effect on the corrosion protection properties was assessed during the accelerated aging. The resistance of the coating was proved to be strongly affected by the surface finishing. UV exposure modified surface properties and graffiti removal efficiency.
      PubDate: 2017-05-06
      DOI: 10.3390/coatings7050067
      Issue No: Vol. 7, No. 5 (2017)
  • Coatings, Vol. 7, Pages 68: Stiffness of Plasma Sprayed Thermal Barrier

    • Authors: Shiladitya Paul
      First page: 68
      Abstract: Thermal spray coatings (TSCs) have complex microstructures and they often operate in demanding environments. Plasma sprayed (PS) thermal barrier coating (TBC) is one such ceramic layer that is applied onto metallic components where a low macroscopic stiffness favors stability by limiting the stresses from differential thermal contraction. In this paper, the Young’s modulus of TBC top coat, measured using different techniques, such as four-point bending, indentation and impulse excitation is reported, along with a brief description of how the techniques probe different length scales. Zirconia-based TBC top coats were found to have a much lower global stiffness than that of dense zirconia. A typical value for the as-sprayed Young’s modulus was ~23 GPa, determined by beam bending. Indentation, probing a local area, gave significantly higher values. The difference between the two stiffness values is thought to explain the wide range of TBC top coat Young’s modulus values reported in the literature. On exposure to high temperature, due to the sintering process, detached top coats exhibit an increase in stiffness. This increase in stiffness caused by the sintering of fine-scale porosity has significant impact on the strain tolerance of the TBC. The paper discusses the different techniques for measuring the Young’s modulus of the TBC top coats and implications of the measured values.
      PubDate: 2017-05-09
      DOI: 10.3390/coatings7050068
      Issue No: Vol. 7, No. 5 (2017)
  • Coatings, Vol. 7, Pages 69: Influence of Heating Conditions for Formation
           of a Thin Apatite Film on Zirconia Using a Molecular Precursor Method

    • Authors: Masatsugu Hirota, Chihiro Mochizuki, Mitsunobu Sato, Tohru Hayakawa
      First page: 69
      Abstract: The influence of heating conditions, heating temperature, and heating time on the formation of a thin carbonate-containing hydroxyapatite (CA) film onto partially stabilized zirconia using a molecular precursor method was evaluated. The molecular precursor solution was prepared from a mixture of calcium-ethylenediaminetetraacetic acid complex and phosphate compounds at Ca/P ratio of 1.67. After the application of molecular precursor solution onto zirconia, four different heating conditions—namely, 600 °C-2 h, 800 °C-2 h, 1000 °C-2 h, and 600 °C-4 h—were applied. No distinct difference of surface appearance of CA coating was observed between 600 and 800 °C-2 h. Fusion of apatite crystals was observed at 1000 °C-2 h. Surface roughness of CA film at 1000 °C-2 h was significantly higher than those under other heating conditions. Heating at 800 °C produced a significantly more hydrophilic surface and higher degree of crystallization. No significant differences were recognized in the critical load at the first crack in the coating among the four samples by scratch tests. After 30 days’ immersion in phosphate buffered saline, the four different CA coating films were still present. Simulated body fluid immersion experiments were performed as in vitro biocompatibility tests. After 48 h immersion, the CA film at 800 °C-2 h showed a greater amount of spherical crystal precipitation. It was suggested that properties of CA coating on partially stabilized zirconia using a molecular precursor method were influenced by the heating temperature and time.
      PubDate: 2017-05-09
      DOI: 10.3390/coatings7050069
      Issue No: Vol. 7, No. 5 (2017)
  • Coatings, Vol. 7, Pages 70: A New Finite Element Formulation for Nonlinear
           Vibration Analysis of the Hard-Coating Cylindrical Shell

    • Authors: Yue Zhang, Wei Sun, Jian Yang
      First page: 70
      Abstract: In this paper, a four-node composite cylindrical shell finite element model based on Love’s first approximation theory is proposed to solve the nonlinear vibration of the hard-coating cylindrical shell efficiently. The developed model may have great significance for vibration reduction of the cylindrical shell structures of the aero engine or aircraft. The influence of the strain dependence of the coating material on the complex stiffness matrix is considered in this model. Nonlinear iterative solution formulas with a unified iterative method are theoretically derived for solving the resonant frequency and response of the composite cylindrical shell. Then, a cylindrical shell coated with a thin layer of NiCoCrAlY + yttria-stabilized zirconia (YSZ) is chosen to demonstrate the proposed formulation, and the rationality is validated by comparing with the finite element iteration method (FEIM). Results show that the developed finite element method is more efficient, and the hard-coating cylindrical shell has the characteristics of soft nonlinearity due to the strain dependence of the coating material.
      PubDate: 2017-05-11
      DOI: 10.3390/coatings7050070
      Issue No: Vol. 7, No. 5 (2017)
  • Coatings, Vol. 7, Pages 71: Predicting the Wear of High Friction Surfacing

    • Authors: David Woodward, Shaun Friel
      First page: 71
      Abstract: High friction surfacing (HFS) is a specialist type of road coating with very high skid resistance. It is used in the UK at locations where there is significant risk of serious or fatal accidents. This paper considers the aggregate used in HFS. Calcined bauxite is the only aggregate that provides the highest levels of skid resistance over the longest period. No naturally occurring aggregate has been found to give a comparable level of in-service performance. This paper reviews the historical development of HFS in the UK relating to aggregate. In-service performance is predicted in the laboratory using the Wear test which subjects test specimens to an estimated 5–8 years simulated trafficking. Examples are given of Wear test data. They illustrate why calcined bauxite performs better than natural aggregate. They show how the amount of calcined bauxite can be reduced by blending with high skid resistant natural aggregates. Data from the Wear test can be related to every HFS laboratory experiment and road trial carried out in the UK for over the last 50 years. Anyone considering the prediction of HFS performance needs to carefully consider the data given in this paper with any other test method currently being considered or used to investigate HFS.
      PubDate: 2017-05-16
      DOI: 10.3390/coatings7050071
      Issue No: Vol. 7, No. 5 (2017)
  • Coatings, Vol. 7, Pages 46: Internally Oxidized Ru–Zr Multilayer

    • Authors: Yung-I Chen, Tso-Shen Lu, Zhi-Ting Zheng
      First page: 46
      Abstract: In this study, equiatomic Ru–Zr coatings were deposited on Si wafers at 400 °C by using direct current magnetron cosputtering. The plasma focused on the circular track of the substrate holder and the substrate holder rotated at speeds within 1–30 rpm, resulting in cyclical gradient concentration in the growth direction. The nanoindentation hardness levels of the as-deposited Ru–Zr coatings increased as the stacking periods of the cyclical gradient concentration decreased. After the coatings were annealed in a 1% O2–99% Ar atmosphere at 600 °C for 30 min, the internally oxidized coatings shifted their respective structures to a laminated structure, misaligned laminated structure, and nanocomposite, depending on their stacking periods. The effects of the stacking period of the cyclical gradient concentration on the mechanical properties and structural evolution of the annealed Ru–Zr coatings were investigated in this study.
      PubDate: 2017-03-23
      DOI: 10.3390/coatings7040046
      Issue No: Vol. 7, No. 4 (2017)
  • Coatings, Vol. 7, Pages 47: Fabrication and Characterization of
           AlxCoFeNiCu1−x High Entropy Alloys by Laser Metal Deposition

    • Authors: Xueyang Chen, Lei Yan, Sreekar Karnati, Yunlu Zhang, Frank Liou
      First page: 47
      Abstract: High entropy alloys are multicomponent alloys that have at least five different principal elements as alloying elements. Each of these elements has an atomic percentage between 5% and 35%. Typically, they form body-centered cubic (bcc) or face-centered cubic (fcc) structure and are known to possess excellent mechanical properties, corrosion resistance, excellent electric and magnetic properties. Owing to their excellent corrosion and wear resistance, researchers are focusing on employing these materials as coatings. In this research, Laser Metal Deposition (LMD) was used to fabricate AlxCoFeNiCu1−x (x = 0.25, 0.5, 0.75) high entropy alloys from elemental powder based feedstocks. Thin wall claddings fabricated via LMD were characterized by a variety of techniques. Data from X-ray Diffraction (XRD) and Electron Back Scatter Diffraction (EBSD) suggested that with increase in Al content and decrease in Cu content, a change in crystal structure from a predominantly fcc to a combined fcc and bcc structure can be observed. The microstructure of the material was observed to be columnar dendritic. Data from standard less EDS analysis showed that the dendritic phase was Fe and Co enriched while the matrix was Cu and Al enriched in all the considered high entropy alloy fabrications. The Vickers hardness data was used to estimate the mechanical properties of these deposits. Results also showed that with the increase in aluminum content, AlxCoFeNiCu1−x displayed higher hardness. The high hardness values imply potential applications in wear resistant coatings.
      PubDate: 2017-03-25
      DOI: 10.3390/coatings7040047
      Issue No: Vol. 7, No. 4 (2017)
  • Coatings, Vol. 7, Pages 48: Statistical Determination of a
           Fretting-Induced Failure of an Electro-Deposited Coating

    • Authors: Kyungmok Kim
      First page: 48
      Abstract: This paper describes statistical determination of fretting-induced failure of an electro-deposited coating. A fretting test is conducted using a ball-on-flat plate configuration. During a test, a frictional force is measured, along with the relative displacement between an AISI52100 ball and a coated flat specimen. Measured data are analyzed with statistical process control tools; a frictional force versus number of fretting cycles is plotted on a control chart. On the control chart, critical number of cycles to coating failure is statistically determined. Fretted surfaces are observed after interrupting a series of fretting tests. Worn surface images and wear profiles provide that the increase on the kinetic friction coefficient after a steady-state sliding is attributed to the substrate enlarged at a contact surface. There is a good agreement between observation of worn surfaces and statistical determination for fretting-induced coating failure.
      PubDate: 2017-03-31
      DOI: 10.3390/coatings7040048
      Issue No: Vol. 7, No. 4 (2017)
  • Coatings, Vol. 7, Pages 49: Hybrid Metaheuristic-Neural Assessment of the
           Adhesion in Existing Cement Composites

    • Authors: Łukasz Sadowski, Mehdi Nikoo, Mohammad Nikoo
      First page: 49
      Abstract: The article presents the hybrid metaheuristic-neural assessment of the pull-off adhesion in existing multi-layer cement composites using artificial neural networks (ANNs) and the imperialist competitive algorithm (ICA). The ICA is a metaheuristic algorithm inspired by the human political-social evolution. This method is based solely on the use of ANNs and two non-destructive testing (NDT) methods: the impact-echo method (I-E) and the impulse response method (IR). In this research, the ICA has been used to optimize the weights of the ANN. The combined ICA-ANN model has been compared to the genetic algorithm (GA) and particle swarm optimization (PSO) to evaluate its accuracy. The results showed that the ICA-ANN model outperforms other techniques when testing datasets in terms of both effectiveness and efficiency. As presented in the validation stage, it is possible to reliably map the adhesion level on a tested surface without local damage to the latter.
      PubDate: 2017-04-01
      DOI: 10.3390/coatings7040049
      Issue No: Vol. 7, No. 4 (2017)
  • Coatings, Vol. 7, Pages 50: Studies on the Effect of Arc Current Mode and
           Substrate Rotation Configuration on the Structure and Corrosion Behavior
           of PVD TiN Coatings

    • Authors: Liam Ward, Antony Pilkington, Steve Dowey
      First page: 50
      Abstract: Thin, hard cathodic arc evaporated (CAE) metal nitride coatings are known to contain defects such as macro-particles, pinholes, voids and increased porosity, leading to reduced corrosion resistance. The focus of this research investigation was to compare the structure and corrosion behaviour of cathodic arc evaporated (CAE) TiN coatings deposited on AISI 1020 low carbon steel substrates using a pulsed current arc and a more conventional constant current arc source (DC). The effects of a double (2R) and triple (3R) substrate rotation configuration were also studied. Coating morphology and chemical composition were characterised using optical, SEM imaging and XRD analysis. Focus variation microscopy (FVM), an optical 3D measurement technique, was used to measure surface roughness. Corrosion studies were carried out using potentiodynamic scanning in 3.5% NaCl. Tafel extrapolation was carried out to determine Ecorr and Icorr values for the coated samples. In general, increased surface roughness, and to a certain extent, corrosion resistance, were associated with thicker coatings deposited using 2R, compared to 3R rotation configuration. The arc source mode (continuous or pulsed) was shown to have little effect on the corrosion behavior. Corrosion behavior was controlled by the presence of defects, pinholes and macro-particles at lower anodic potentials, while the formation of large pitted regions and aggressive corrosion of the underlying substrate was observed at higher anodic potentials.
      PubDate: 2017-04-04
      DOI: 10.3390/coatings7040050
      Issue No: Vol. 7, No. 4 (2017)
  • Coatings, Vol. 7, Pages 51: Effect on Concrete Surface Water Absorption
           upon Addition of Lactate Derived Agent

    • Authors: Renee Mors, Henk Jonkers
      First page: 51
      Abstract: Water tightness of a concrete cover layer is important, as it is typically used as a protective coating of the steel reinforcement. Water tightness can be impaired by crack formation or by permeability. A bacteria-based lactate-derived healing agent (HA) can be added to concrete to enhance the potential for restoration of water tightness. Bacterial conversion of the included carbon source results in CO2 production and subsequent CaCO3 precipitation, similar to the mechanism of concrete carbonation. Carbonation is known to densify concrete, particularly when using ordinary Portland cement (OPC), but to a much lower extend in slag-based concrete (CEM III/B). To identify the effect of HA addition on concrete properties, this study focusses on the ingress of moisture in non-cracked concrete surfaces by assessing capillary water absorption. Surface properties were determined for sealed and unsealed surfaces of concrete—either based on OPC or CEM III/B—before and after curing under three different conditions: Dry, wet, or humid. HA addition to concrete containing slag cement generated a surface less prone to continued drying, but resulted in higher water absorption. In contrast, surface water absorption significantly decreased upon HA addition to OPC-based samples, independent of the curing regime. It is therefore concluded that HA in its current form is suitable for application in OPC, but less in CEM III/B-based mixtures.
      PubDate: 2017-04-07
      DOI: 10.3390/coatings7040051
      Issue No: Vol. 7, No. 4 (2017)
  • Coatings, Vol. 7, Pages 52: The Effect of Temperature and Local pH on
           Calcareous Deposit Formation in Damaged Thermal Spray Aluminum (TSA)
           Coatings and Its Implication on Corrosion Mitigation of Offshore Steel

    • Authors: Nataly Ce, Shiladitya Paul
      First page: 52
      Abstract: This paper is based on experimental data and provides better understanding of the mechanism of calcareous deposit formation on cathodically polarized steel surfaces exposed to synthetic seawater at 30 °C and 60 °C. The study comprises measurement of the interfacial pH of thermally sprayed aluminum (TSA) coated steel samples with and without a holiday (exposing 20% of the surface area). Tests were conducted at the corrosion potential for up to 350 h. It was experimentally determined that the local pH adjacent to the steel surface in the holiday region reached a maximum of 10.19 and 9.54 at 30 °C and 60 °C, respectively, before stabilizing at about 8.8 and 7.9 at the two temperatures. The interfacial pH on the TSA coating at 30 °C was initially 7.74 dropping to 4.76 in 220 h, while at 60 °C it increased from pH 6.41 to the range pH 7.0–8.5. The interfacial pH governed the deposition of brucite and aragonite from seawater on the steel surface cathodically polarized by the TSA. This mechanism is likely to affect the performance of TSA-coated offshore steel structures, especially when damaged in service.
      PubDate: 2017-04-11
      DOI: 10.3390/coatings7040052
      Issue No: Vol. 7, No. 4 (2017)
  • Coatings, Vol. 7, Pages 53: Preparation of Metal Coatings on Steel Balls
           Using Mechanical Coating Technique and Its Process Analysis

    • Authors: Liang Hao, Hiroyuki Yoshida, Takaomi Itoi, Yun Lu
      First page: 53
      Abstract: We successfully applied mechanical coating technique to prepare Ti coatings on the substrates of steel balls and stainless steel balls. The prepared samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The weight increase of the ball substrates and the average thickness of Ti coatings were also monitored. The results show that continuous Ti coatings were prepared at different revolution speeds after different durations. Higher revolution speed can accelerate the formation of continuous Ti coatings. Substrate hardness also markedly affected the formation of Ti coatings. Specifically, the substance with lower surface hardness was more suitable as the substrate on which to prepare Ti coatings. The substrate material plays a key role in the formation of Ti coatings. Specifically, Ti coatings formed more easily on metal/alloy balls than ceramic balls. The above conclusion can also be applied to other metal or alloy coatings on metal/alloy and ceramic substrates.
      PubDate: 2017-04-10
      DOI: 10.3390/coatings7040053
      Issue No: Vol. 7, No. 4 (2017)
  • Coatings, Vol. 7, Pages 54: Erosion Wear Investigation of HVOF Sprayed
           WC-10Co4Cr Coating on Slurry Pipeline Materials

    • Authors: Kaushal Kumar, Satish Kumar, Gurprit Singh, Jatinder Singh, Jashanpreet Singh
      First page: 54
      Abstract: In the present work, erosion wear due to slurry mixture flow has been investigated using a slurry erosion pot tester. Erosion tests are conducted on three different slurry pipe materials, namely, mild steel, SS202, and SS304, to establish the influence of rotational speed, concentration, and time period. In order to increase erosion wear resistance, a high-velocity oxy-fuel (HVOF) coating technique is used to deposit a WC-10Co4Cr coating on the surface of all piping materials. Experimental results show that rotational speed is a highly-influencing parameter for the erosion wear rate as compared to solid concentration, time duration, and weighted mean diameter. WC-10Co4Cr HVOF coating improved the erosion resistance of piping materials up to 3.5 times. From experimental data, the exponents of solid concentration, velocity, and the size of particles are calculated for the empirical erosion wear equation. A functional equation of the erosion wear rate is developed. The predicted erosion wear is in agreement with the experimental data and found to be within a deviation of ±12%.
      PubDate: 2017-04-12
      DOI: 10.3390/coatings7040054
      Issue No: Vol. 7, No. 4 (2017)
  • Coatings, Vol. 7, Pages 55: Application of High-Velocity Oxygen-Fuel
           (HVOF) Spraying to the Fabrication of Yb-Silicate Environmental Barrier

    • Authors: Emine Bakan, Georg Mauer, Yoo Sohn, Dietmar Koch, Robert Vaßen
      First page: 55
      Abstract: From the literature, it is known that due to their glass formation tendency, it is not possible to deposit fully-crystalline silicate coatings when the conventional atmospheric plasma spraying (APS) process is employed. In APS, rapid quenching of the sprayed material on the substrate facilitates the amorphous deposit formation, which shrinks when exposed to heat and forms pores and/or cracks. This paper explores the feasibility of using a high-velocity oxygen-fuel (HVOF) process for the cost-effective fabrication of dense, stoichiometric, and crystalline Yb2Si2O7 environmental barrier coatings. We report our findings on the HVOF process optimization and its resultant influence on the microstructure development and crystallinity of the Yb2Si2O7 coatings. The results reveal that partially crystalline, dense, and vertical crack-free EBCs can be produced by the HVOF technique. However, the furnace thermal cycling results revealed that the bonding of the Yb2Si2O7 layer to the Silicon bond coat needs to be improved.
      PubDate: 2017-04-18
      DOI: 10.3390/coatings7040055
      Issue No: Vol. 7, No. 4 (2017)
  • Coatings, Vol. 7, Pages 56: State of the Art of Antimicrobial Edible
           Coatings for Food Packaging Applications

    • Authors: Arantzazu Valdés, Marina Ramos, Ana Beltrán, Alfonso Jiménez, María Garrigós
      First page: 56
      Abstract: The interest for the development of new active packaging materials has rapidly increased in the last few years. Antimicrobial active packaging is a potential alternative to protect perishable products during their preparation, storage and distribution to increase their shelf-life by reducing bacterial and fungal growth. This review underlines the most recent trends in the use of new edible coatings enriched with antimicrobial agents to reduce the growth of different microorganisms, such as Gram-negative and Gram-positive bacteria, molds and yeasts. The application of edible biopolymers directly extracted from biomass (proteins, lipids and polysaccharides) or their combinations, by themselves or enriched with natural extracts, essential oils, bacteriocins, metals or enzyme systems, such as lactoperoxidase, have shown interesting properties to reduce the contamination and decomposition of perishable food products, mainly fish, meat, fruits and vegetables. These formulations can be also applied to food products to control gas exchange, moisture permeation and oxidation processes.
      PubDate: 2017-04-19
      DOI: 10.3390/coatings7040056
      Issue No: Vol. 7, No. 4 (2017)
  • Coatings, Vol. 7, Pages 35: Pitted Corrosion Detection of Thermal Sprayed
           Metallic Coatings Using Fiber Bragg Grating Sensors

    • Authors: Fodan Deng, Ying Huang, Fardad Azarmi, Yechun Wang
      First page: 35
      Abstract: Metallic coatings using thermal spraying techniques are widely applied to structural steels to protect infrastructure against corrosion and improve durability of the associated structures for longer service life. The thermal sprayed metallic coatings consisting of various metals, although have higher corrosion resistance, will still corrode in a long run and may also subject to corrosion induced damages such as cracks. Corrosion and the induced damages on the metallic coatings will reduce the effectiveness of the coatings for protection of the structures. Timely repair on these damaged metallic coatings will significantly improve the reliability of protected structures again deterioration. In this paper, an inline detection system for corrosion and crack detection was developed using fiber Bragg (FBG) grating sensors. Experimental results from laboratory accelerated corrosion tests showed that the developed sensing system can quantitatively detect corrosion rate of the coating, corrosion propagations, and cracks initialized in the metallic coating in real time. The developed system can be used for real-time corrosion detection of coated metal structures in field.
      PubDate: 2017-02-24
      DOI: 10.3390/coatings7030035
      Issue No: Vol. 7, No. 3 (2017)
  • Coatings, Vol. 7, Pages 36: Effect of Electrochemically Deposited MgO
           Coating on Printable Perovskite Solar Cell Performance

    • Authors: T. A. Peiris, Ajay Baranwal, Hiroyuki Kanda, Shouta Fukumoto, Shusaku Kanaya, Takeru Bessho, Ludmila Cojocaru, Tsutomu Miyasaka, Hiroshi Segawa, Seigo Ito
      First page: 36
      Abstract: Herein, we studied the effect of MgO coating thickness on the performance of printable perovskite solar cells (PSCs) by varying the electrodeposition time of Mg(OH)2 on the fluorine-doped tin oxide (FTO)/TiO2 electrode. Electrodeposited Mg(OH)2 in the electrode was confirmed by energy dispersive X-ray (EDX) analysis and scanning electron microscopic (SEM) images. The performance of printable PSC structures on different deposition times of Mg(OH)2 was evaluated on the basis of their photocurrent density-voltage characteristics. The overall results confirmed that the insulating MgO coating has an adverse effect on the photovoltaic performance of the solid state printable PSCs. However, a marginal improvement in the device efficiency was obtained for the device made with the 30 s electrodeposited TiO2 electrode. We believe that this undesirable effect on the photovoltaic performance of the printable PSCs is due to the higher coverage of TiO2 by the insulating MgO layer attained by the electrodeposition technique.
      PubDate: 2017-02-27
      DOI: 10.3390/coatings7030036
      Issue No: Vol. 7, No. 3 (2017)
  • Coatings, Vol. 7, Pages 37: Investigation of Coating Performance of
           UV-Curable Hybrid Polymers Containing
           1H,1H,2H,2H-Perfluorooctyltriethoxysilane Coated on Aluminum Substrates

    • Authors: Mustafa Çakır
      First page: 37
      Abstract: This study describes preparation and characterization of fluorine-containing organic-inorganic hybrid coatings. The organic part consists of bisphenol-A glycerolate (1 glycerol/phenol) diacrylate resin and 1,6-hexanediol diacrylate reactive diluent. The inorganically rich part comprises trimethoxysilane-terminated urethane, 1H,1H,2H,2H-perfluorooctyltriethoxysilane, 3-(trimethoxysilyl) propyl methacrylate and sol–gel precursors that are products of hydrolysis and condensation reactions. Bisphenol-A glycerolate (1 glycerol/phenol) diacrylate resin was added to the inorganic part in predetermined amounts. The resultant mixture was utilized in the preparation of free films as well as coatings on aluminum substrates. Thermal and mechanical tests such as DSC, thermo-gravimetric analysis (TGA), and tensile and shore D hardness tests were performed on free films. Water contact angle, gloss, Taber abrasion test, cross-cut and tubular impact tests were conducted on the coated samples. SEM examination and EDS analysis was performed on the fractured surfaces of free films. The hybrid coatings on the aluminum sheets gave rise to properties such as moderately glossed surface; low wear rate and hydrophobicity. Tensile strength of free films increased with up to 10% inorganic content in the hybrid structure and this increase was approximately three times that of the control sample. As expected; the % strain value decreased by 17.3 with the increase in inorganic content and elastic modulus values increased by a factor of approximately 6. Resistance to ketone-based solvents was proven and an increase in hardness was observed as the ratio of the inorganic part increased. Samples which contain 10% sol–gel content were observed to provide optimal properties.
      PubDate: 2017-03-02
      DOI: 10.3390/coatings7030037
      Issue No: Vol. 7, No. 3 (2017)
  • Coatings, Vol. 7, Pages 38: A Field Performance Evaluation Scheme for
           Microwave-Absorbing Material Coatings

    • Authors: Shaopeng Guan, Yongyu Wang, Daiping Jia
      First page: 38
      Abstract: Performance evaluation is an important aspect in the study of microwave-absorbing material coatings. The reflectivity of the incident wave is usually taken as the performance indicator. There have been various methods to directly or indirectly measure the reflectivity, but existing methods are mostly cumbersome and require a strict testing environment. What is more, they cannot be applied to field measurement. In this paper, we propose a scheme to achieve field performance evaluation of microwave-absorbing materials, which adopts a small H-plane sectoral horn antenna as the testing probe and a small microwave reflectometer as the indicator. When the size of the H-plane sectoral horn antenna is specially designed, the field distribution at the antenna aperture can be approximated as a plane wave similar to the far field of the microwave emitted by a radar unit. Therefore, the reflectivity can be obtained by a near-field measurement. We conducted experiments on a kind of ferrite-based microwave-absorbing material at X band (8.2–12.4 GHz) to validate the scheme. The experimental results show that the reflectivity is in agreement with the reference data measured by the conventional method as a whole.
      PubDate: 2017-03-02
      DOI: 10.3390/coatings7030038
      Issue No: Vol. 7, No. 3 (2017)
  • Coatings, Vol. 7, Pages 39: Influence of the Electrolyte Concentration on
           the Smooth TiO2 Anodic Coatings on Ti-6Al-4V

    • Authors: María Vera, Ángeles Colaccio, Mario Rosenberger, Carlos Schvezov, Alicia Ares
      First page: 39
      Abstract: To obtain smooth TiO2 coatings for building a new design of Ti-6Al-4V heart valve, the anodic oxidation technique in pre-spark conditions was evaluated. TiO2 coating is necessary for its recognized biocompatibility and corrosion resistance. A required feature on surfaces in contact with blood is a low level of roughness (Ra ≤ 50 nm) that does not favor the formation of blood clots. The present paper compares the coatings obtained by anodic oxidation of the Ti-6Al-4V alloy using H2SO4 at different concentrations (0.1–4 M) as electrolyte and applying different voltages (from 20 to 70 V). Color and morphological analysis of coatings are performed using optical and scanning microscopy. The crystalline phases were analyzed by glancing X-ray diffraction. By varying the applied voltage, different interference colors coatings were obtained. The differences in morphologies of the coatings caused by changes in acid concentration are more evident at high voltages, limiting the oxidation conditions for the desired application. Anatase phase was detected from 70 V for 1 M H2SO4. An increase in the concentration of H2SO4 decreases the voltage at which the transformation of amorphous to crystalline coatings occurs; i.e., with 4 M H2SO4, the anatase phase appears at 60 V.
      PubDate: 2017-03-03
      DOI: 10.3390/coatings7030039
      Issue No: Vol. 7, No. 3 (2017)
  • Coatings, Vol. 7, Pages 40: Development of a Fabrication Process Using
           Suspension Plasma Spray for Titanium Oxide Photovoltaic Device

    • Authors: Hsian Sagr Hadi A, Yasutaka Ando
      First page: 40
      Abstract: In order to reduce the high costs of conventional materials, and to reduce the power necessary for the deposition of titanium dioxide, titanium tetrabutoxide has been developed in the form of a suspension of TiO2 using water instead of expensive ethanol. To avoid sedimentation of hydroxide particles in the suspension, mechanical milling of the suspension was conducted in order to create diffusion in colloidal suspension before using it as feedstock. Consequently, through the creation of a colloidal suspension, coating deposition was able to be conducted without sedimentation of the hydroxide particles in the suspension during the deposition process. Though an amorphous as-deposited coating was able to be deposited, through post heat treatment at 630 °C for 60 min, the chemical structure became anatase rich. In addition, it was confirmed that the post heat treated anatase rich coating had enough photo-catalytic activity to decolor methylene-blue droplets. From these results, this technique was found to have high potential in the low cost photo-catalytic titanium coating production process.
      PubDate: 2017-03-04
      DOI: 10.3390/coatings7030040
      Issue No: Vol. 7, No. 3 (2017)
  • Coatings, Vol. 7, Pages 41: Ozone Resistance, Water Permeability, and
           Concrete Adhesion of Metallic Films Sprayed on a Concrete Structure for
           Advanced Water Purification

    • Authors: Jin-Ho Park, Jitendra Singh, Han-Seung Lee
      First page: 41
      Abstract: We evaluated the applicability of metal spray coating as a waterproofing/corrosion protection method for a concrete structure used for water purification. We carried out an ozone resistance test on four metal sprays and evaluated the water permeability and bond strength of the metals with superior ozone resistance, depending on the surface treatment method. In the ozone resistance test, four metal sprays and an existing ozone-proof paint were considered. In the experiment on the water permeability and bond strength depending on the surface treatment method, the methods of no treatment, surface polishing, and two types of pore sealing agents were considered. The results showed that the sprayed titanium had the best ozone resistance. Applying a pore sealing agent provided the best adhesion performance, of about 3.2 MPa. Applying a pore sealing agent also provided the best waterproofing performance. Scanning electron microscope analysis showed that applying a pore sealing agent resulted in an excellent waterproofing performance because a coating film formed on top of the metal spray coating. Thus, when using a metal spray as waterproofing/corrosion protection for a water treatment concrete structure, applying a pore sealing agent on top of a film formed by spraying titanium was concluded to be the most appropriate method.
      PubDate: 2017-03-10
      DOI: 10.3390/coatings7030041
      Issue No: Vol. 7, No. 3 (2017)
  • Coatings, Vol. 7, Pages 42: Defect-Free Large-Area (25 cm2) Light
           Absorbing Perovskite Thin Films Made by Spray Coating

    • Authors: Mehran Habibi, Amin Rahimzadeh, Inas Bennouna, Morteza Eslamian
      First page: 42
      Abstract: In this work, we report on reproducible fabrication of defect-free large-area mixed halide perovskite (CH3NH3PbI3−xClx) thin films by scalable spray coating with the area of 25 cm2. This is essential for the commercialization of the perovskite solar cell technology. Using an automated spray coater, the film thickness and roughness were optimized by controlling the solution concentration and substrate temperature. For the first time, the surface tension, contact angle, and viscosity of mixed halide perovskite dissolved in dimethylformamide (DMF) are reported as a function of the solution concentration. A low perovskite solution concentration of 10% was selected as an acceptable value to avoid crystallization dewetting. The determined optimum substrate temperature of 150 °C, followed by annealing at 100 °C render the highest perovskite precursor conversion, as well as the highest possible droplet spreading, desired to achieve a continuous thin film. The number of spray passes was also tuned to achieve a fully-covered film, for the condition of the spray nozzle used in this work. This work demonstrates that applying the optimum substrate temperature decreases the standard deviation of the film thickness and roughness, leading to an increase in the quality and reproducibility of the large-area spray-on films. The optimum perovskite solution concentration and the substrate temperature are universally applicable to other spray coating systems.
      PubDate: 2017-03-12
      DOI: 10.3390/coatings7030042
      Issue No: Vol. 7, No. 3 (2017)
  • Coatings, Vol. 7, Pages 43: Investigation of a Simplified Mechanism Model
           for Prediction of Gallium Nitride Thin Film Growth through Numerical

    • Authors: Chih-Kai Hu, Chun-Jung Chen, Ta-Chin Wei, Tomi Li, Ching-Chiun Wang, Chih-Yung Huang
      First page: 43
      Abstract: A numerical procedure was performed to simplify the complicated mechanism of an epitaxial thin-film growth process. In this study, three numerical mechanism models are presented for verifying the growth rate of the gallium nitride (GaN) mechanism. The mechanism models were developed through rate of production analysis. All of the results can be compared in one schematic diagram, and the differences among these three mechanisms are pronounced at high temperatures. The simplified reaction mechanisms were then used as input for a two-dimensional computational fluid dynamics code FLUENT, enabling the accurate prediction of growth rates. Validation studies are presented for two types of laboratory-scale reactors (vertical and horizontal). A computational study including thermal and flow field was also performed to investigate the fluid dynamic in those reactors. For each study, the predictions agree acceptably well with the experimental data, indicating the reasonable accuracy of the reaction mechanisms.
      PubDate: 2017-03-15
      DOI: 10.3390/coatings7030043
      Issue No: Vol. 7, No. 3 (2017)
  • Coatings, Vol. 7, Pages 44: High-Temperature Corrosion of AlCrSiN Film in
           Ar-1%SO2 Gas

    • Authors: Poonam Yadav, Dong Lee, Yue Lin, Shihong Zhang, Sik Kwon
      First page: 44
      Abstract: AlCrSiN film with a composition of 29.1Al-17.1Cr-2.1Si-51.7N in at. % was deposited on a steel substrate by cathodic arc ion plating at a thickness of 1.8 μm. It consisted of nanocrystalline hcp-AlN and fcc-CrN, where a small amount of Si was dissolved. Corrosion tests were carried out at 800 °C for 5–200 h in Ar-1%SO2 gas. The major corrosion reaction was oxidation owing to the high oxygen affinity of Al and Cr in the film. The formed oxide scale consisted primarily of (Al,Cr)2O3, within which Fe, Si, and S were dissolved. Even after corrosion for 200 h, the thickness of the scale was about 0.7–1.2 μm, indicating that the film had good corrosion resistance in the SO2-containing atmosphere.
      PubDate: 2017-03-13
      DOI: 10.3390/coatings7030044
      Issue No: Vol. 7, No. 3 (2017)
  • Coatings, Vol. 7, Pages 45: Review of Antibacterial Activity of
           Titanium-Based Implants’ Surfaces Fabricated by Micro-Arc Oxidation

    • Authors: Xiaojing He, Xiangyu Zhang, Xin Wang, Lin Qin
      First page: 45
      Abstract: Ti and its alloys are the most commonly-used materials for biomedical applications. However, bacterial infection after implant placement is still one of the significant rising complications. Therefore, the application of the antimicrobial agents into implant surfaces to prevent implant-associated infection has attracted much attention. Scientific papers have shown that inorganic antibacterial metal elements (e.g., Ag, Cu, Zn) can be introduced into implant surfaces with the addition of metal nanoparticles or metallic compounds into an electrolyte via micro-arc oxidation (MAO) technology. In this review, the effects of the composition and concentration of electrolyte and process parameters (e.g., voltage, current density, oxidation time) on the morphological characteristics (e.g., surface morphology, bonding strength), antibacterial ability and biocompatibility of MAO antimicrobial coatings are discussed in detail. Anti-infection and osseointegration can be simultaneously accomplished with the selection of the proper antibacterial elements and operating parameters. Besides, MAO assisted by magnetron sputtering (MS) to endow Ti-based implant materials with superior antibacterial ability and biocompatibility is also discussed. Finally, the development trend of MAO technology in the future is forecasted.
      PubDate: 2017-03-22
      DOI: 10.3390/coatings7030045
      Issue No: Vol. 7, No. 3 (2017)
  • Coatings, Vol. 7, Pages 17: Electroplating of CdTe Thin Films from Cadmium
           Sulphate Precursor and Comparison of Layers Grown by 3-Electrode and
           2-Electrode Systems

    • Authors: Imyhamy Dharmadasa, Mohammad Madugu, Olajide Olusola, Obi Echendu, Fijay Fauzi, Dahiru Diso, Ajith Weerasinghe, Thad Druffel, Ruvini Dharmadasa, Brandon Lavery, Jacek Jasinski, Tatiana Krentsel, Gamini Sumanasekera
      First page: 17
      Abstract: Electrodeposition of CdTe thin films was carried out from the late 1970s using the cadmium sulphate precursor. The solar energy group at Sheffield Hallam University has carried out a comprehensive study of CdTe thin films electroplated using cadmium sulfate, cadmium nitrate and cadmium chloride precursors, in order to select the best electrolyte. Some of these results have been published elsewhere, and this manuscript presents the summary of the results obtained on CdTe layers grown from cadmium sulphate precursor. In addition, this research program has been exploring the ways of eliminating the reference electrode, since this is a possible source of detrimental impurities, such as K+ and Ag+ for CdS/CdTe solar cells. This paper compares the results obtained from CdTe layers grown by three-electrode (3E) and two-electrode (2E) systems for their material properties and performance in CdS/CdTe devices. Thin films were characterized using a wide range of analytical techniques for their structural, morphological, optical and electrical properties. These layers have also been used in device structures; glass/FTO/CdS/CdTe/Au and CdTe from both methods have produced solar cells to date with efficiencies in the region of 5%–13%. Comprehensive work carried out to date produced comparable and superior devices fabricated from materials grown using 2E system.
      PubDate: 2017-01-24
      DOI: 10.3390/coatings7020017
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 18: Influence of the Distribution of a Spray Paint
           on the Efficacy of Anti-Graffiti Coatings on a Highly Porous Natural Stone

    • Authors: Maurizio Masieri, Mariateresa Lettieri
      First page: 18
      Abstract: Graffiti on facades often has a heavy impact in social and economic terms, particularly when historical and artistic artefacts are affected. To limit the damages to the surfaces, preventive plans are implemented and anti-graffiti coatings are used as a protective measure. In this study, the distribution of a spray paint inside a highly porous stone, with and without anti-graffiti protection, was investigated. Two commercial sacrificial anti-graffiti systems were used and an acrylic-based paint was applied as staining agent. Environmental scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDS) microanalysis were performed to characterise, from the morphological and chemical point of view, the anti-graffiti coatings and the paint. Maps of the main elements were acquired to locate the different products inside the stone. Chemical removers were used to clean the stained surfaces, then the effectiveness of the cleaning was assessed by visual observations and colour measurements, as well as on the basis of percentage of residual stain. The obtained results highlighted that the anti-graffiti efficacy strongly depended on the characteristics of the applied coating. This latter usually acted as a barrier, but good results were obtained only where the stain did not remain as a separate layer, but penetrated the protective coating. Microcracks in the anti-graffiti coating were able to nullify the protective action.
      PubDate: 2017-01-24
      DOI: 10.3390/coatings7020018
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 19: Fabrication of Efficient Cu2ZnSnS4 Solar Cells
           by Sputtering Single Stoichiometric Target

    • Authors: Hongtao Cui, Xiaolei Liu, Lingling Sun, Fangyang Liu, Chang Yan, Xiaojing Hao
      First page: 19
      Abstract: Low cost single stoichiometric target sputtering of Cu2ZnSnS4 (CZTS) precursor has been adopted to fabricate CZTS solar cells. The effect of a series of deposition pressures and deposition durations on the device performance has been investigated. A 3.74% efficient solar cell has been achieved at a base pressure of 1 × 10−4 Torr with a stoichiometric target, which to the authors’ knowledge, is the record efficiency for such a stoichiometric target.
      PubDate: 2017-01-24
      DOI: 10.3390/coatings7020019
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 20: Recent Developments in Accelerated
           Antibacterial Inactivation on 2D Cu-Titania Surfaces under Indoor Visible

    • Authors: Sami Rtimi, Cesar Pulgarin, John Kiwi
      First page: 20
      Abstract: This review focuses on Cu/TiO2 sequentially sputtered and Cu-TiO2 co-sputtered catalytic/photocatalytic surfaces that lead to bacterial inactivation, discussing their stability, synthesis, adhesion, and antibacterial kinetics. The intervention of TiO2, Cu, and the synergic effect of Cu and TiO2 on films prepared by a colloidal sol-gel method leading to bacterial inactivation is reviewed. Processes in aerobic and anaerobic media leading to bacterial loss of viability in multidrug resistant (MDR) pathogens, Gram-negative, and Gram-positive bacteria are described. Insight is provided for the interfacial charge transfer mechanism under solar irradiation occurring between TiO2 and Cu. Surface properties of 2D TiO2/Cu and TiO2-Cu films are correlated with the bacterial inactivation kinetics in dark and under light conditions. The intervention of these antibacterial sputtered surfaces in health-care facilities, leading to Methicillin-resistant Staphylococcus Aureus (MRSA)-isolates inactivation, is described in dark and under actinic light conditions. The synergic intervention of the Cu and TiO2 films leading to bacterial inactivation prepared by direct current magnetron sputtering (DCMS), pulsed direct current magnetron sputtering (DCMSP), and high power impulse magnetron sputtering (HIPIMS) is reported in a detailed manner.
      PubDate: 2017-02-06
      DOI: 10.3390/coatings7020020
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 21: Interfacial Mechanics Analysis of a Brittle
           Coating–Ductile Substrate System Involved in Thermoelastic Contact

    • Authors: Chi Zhang, Le Gu, Chongyang Nie, Chuanwei Zhang, Liqin Wang
      First page: 21
      Abstract: In this paper, interfacial stress analysis for a brittle coating/ductile substrate system, which is involved in a sliding contact with a rigid ball, is presented. By combining interface mechanics theory and the image point method, stress and displacement responses within a coated material for normal load, tangential load, and thermal load are obtained; further, the Green’s functions are established. The effects of coating thickness, friction coefficient, and a coating’s thermoelastic properties on the interfacial shear stress, τxz, and transverse stress, σxx, distributions are discussed in detail. A phenomenon, where interfacial shear stress tends to be relieved by frictional heating, is found in the case of a coating material’s thermal expansion coefficient being less than a substrate material’s thermal expansion coefficient. Additionally, numerical results show that distribution of interfacial stress can be altered and, therefore, interfacial damage can be modified by adjusting a coating’s structural parameters and thermoelastic properties.
      PubDate: 2017-02-06
      DOI: 10.3390/coatings7020021
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 22: Multiscale Computational Fluid Dynamics:
           Methodology and Application to PECVD of Thin Film Solar Cells

    • Authors: Marquis Crose, Anh Tran, Panagiotis Christofides
      First page: 22
      Abstract: This work focuses on the development of a multiscale computational fluid dynamics (CFD) simulation framework with application to plasma-enhanced chemical vapor deposition of thin film solar cells. A macroscopic, CFD model is proposed which is capable of accurately reproducing plasma chemistry and transport phenomena within a 2D axisymmetric reactor geometry. Additionally, the complex interactions that take place on the surface of a-Si:H thin films are coupled with the CFD simulation using a novel kinetic Monte Carlo scheme which describes the thin film growth, leading to a multiscale CFD model. Due to the significant computational challenges imposed by this multiscale CFD model, a parallel computation strategy is presented which allows for reduced processing time via the discretization of both the gas-phase mesh and microscopic thin film growth processes. Finally, the multiscale CFD model has been applied to the PECVD process at industrially relevant operating conditions revealing non-uniformities greater than 20% in the growth rate of amorphous silicon films across the radius of the wafer.
      PubDate: 2017-02-08
      DOI: 10.3390/coatings7020022
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 23: Silicides and Nitrides Formation in Ti Films
           Coated on Si and Exposed to (Ar-N2-H2) Expanding Plasma

    • Authors: Isabelle Jauberteau, Richard Mayet, Julie Cornette, Denis Mangin, Annie Bessaudou, Pierre Carles, Jean Jauberteau, Armand Passelergue
      First page: 23
      Abstract: The physical properties including the mechanical, optical and electrical properties of Ti nitrides and silicides are very attractive for many applications such as protective coatings, barriers of diffusion, interconnects and so on. The simultaneous formation of nitrides and silicides in Ti films improves their electrical properties. Ti films coated on Si wafers are heated at various temperatures and processed in expanding microwave (Ar-N2-H2) plasma for various treatment durations. The Ti-Si interface is the centre of Si diffusion into the Ti lattice and the formation of various Ti silicides, while the Ti surface is the centre of N diffusion into the Ti film and the formation of Ti nitrides. The growth of silicides and nitrides gives rise to two competing processes which are thermodynamically and kinetically controlled. The effect of thickness on the kinetics of the formation of silicides is identified. The metastable C49TiSi2 phase is the main precursor of the stable C54TiSi2 phase, which crystallizes at about 600 °C, while TiN crystallizes at about 800 °C.
      PubDate: 2017-02-08
      DOI: 10.3390/coatings7020023
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 24: Using an Atmospheric Pressure Chemical Vapor
           Deposition Process for the Development of V2O5 as an Electrochromic

    • Authors: Dimitra Vernardou
      First page: 24
      Abstract: Vanadium pentoxide coatings were grown by atmospheric pressure chemical vapor deposition varying the gas precursor ratio (vanadium (IV) chloride:water) and the substrate temperature. All samples were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, cyclic voltammetry, and transmittance measurements. The water flow rate was found to affect the crystallinity and the morphological characteristics of vanadium pentoxide. Dense stacks of long grains of crystalline oxide are formed at the highest amount of water utilized for a substrate temperature of 450 °C. Accordingly, it was indicated that for higher temperatures and a constant gas precursor ratio of 1:7, the surface morphology becomes flattened, and columnar grains of uniform size and shape are indicated, keeping the high crystalline quality of the material. Hence, it was possible to define a frame of operating parameters wherein single-phase vanadium pentoxide may be reliably expected, including a gas precursor ratio of 1:7 with a substrate temperature of >450 °C. The as-grown vanadium pentoxide at 550 °C for a gas precursor ratio of 1:7 presented the best electrochemical performance, including a diffusion coefficient of 9.19 × 10−11 cm2·s−1, a charge density of 3.1 mC·cm−2, and a coloration efficiency of 336 cm2·C−1. One may then say that this route can be important for the growth of large-scale electrodes with good performance for electrochromic devices.
      PubDate: 2017-02-08
      DOI: 10.3390/coatings7020024
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 25: Corrosion Protection Systems and Fatigue
           Corrosion in Offshore Wind Structures: Current Status and Future

    • Authors: Seth Price, Rita Figueira
      First page: 25
      Abstract: Concerns over reducing CO2 emissions associated with the burning of fossil fuels in combination with an increase in worldwide energy demands is leading to increased development of renewable energies such as wind. The installation of offshore wind power structures (OWS) is one of the most promising approaches for the production of renewable energy. However, corrosion and fatigue damage in marine and offshore environments are major causes of primary steel strength degradation in OWS. Corrosion can reduce the thickness of structural components which may lead towards fatigue crack initiation and buckling. These failure mechanisms affect tower service life and may result in catastrophic structural failure. Additionally, environmental pollution stemming from corrosion’s by-products is possible. As a result, large financial investments are made yearly for both the prevention and recovery of these drawbacks. The corrosion rate of an OWS is dependent on different characteristics of attack which are influenced by access to oxygen and humidity. Structural degradation can occur due to chemical attack, abrasive action of waves, and microorganism attacks. Inspired by technological and scientific advances in recent years, the purpose of this paper is to discuss the current protective coating system technologies used to protect OWS as well as future perspectives.
      PubDate: 2017-02-11
      DOI: 10.3390/coatings7020025
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 26: Surface Enhanced Raman Scattering Substrates
           Made by Oblique Angle Deposition: Methods and Applications

    • Authors: Hin Chu, Shigeng Song, Cheng Li, Des Gibson
      First page: 26
      Abstract: Surface Enhanced Raman Spectroscopy presents a rapid, non-destructive method to identify chemical and biological samples with up to single molecule sensitivity. Since its discovery in 1974, the technique has become an intense field of interdisciplinary research, typically generating >2000 publications per year since 2011. The technique relies on the localised surface plasmon resonance phenomenon, where incident light can couple with plasmons at the interface that result in the generation of an intense electric field. This field can propagate from the surface from the metal-dielectric interface, so molecules within proximity will experience more intense Raman scattering. Localised surface plasmon resonance wavelength is determined by a number of factors, such as size, geometry and material. Due to the requirements of the surface optical response, Ag and Au are typical metals used for surface enhanced Raman applications. These metals then need to have nano features that improve the localised surface plasmon resonance, several variants of these substrates exist; surfaces can range from nanoparticles in a suspension, electrochemically roughened electrodes to metal nanostructures on a substrate. The latter will be the focus of this review, particularly reviewing substrates made by oblique angle deposition. Oblique angle deposition is the technique of growing thin films so that the material flux is not normal to the surface. Films grown in this fashion will possess nanostructures, due to the atomic self-shadowing effect, that are dependent mainly on the deposition angle. Recent developments, applications and highlights of surface enhanced Raman scattering substrates made by oblique angle deposition will be reviewed.
      PubDate: 2017-02-15
      DOI: 10.3390/coatings7020026
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 27: Coating Qualities Deposited Using Three
           Different Thermal Spray Technologies in Relation with Temperatures and
           Velocities of Spray Droplets

    • Authors: Yasuyuki Kawaguchi, Fumihiro Miyazaki, Masafumi Yamasaki, Yukihiko Yamagata, Nozomi Kobayashi, Katsunori Muraoka
      First page: 27
      Abstract: Three guns based on different thermal spray technologies—namely, gas flame spray, wire arc spray, and wire plasma spray—were operated at each best cost–performance condition, and the resulting spray droplets and deposited coating qualities were investigated. For the former, a simple optical monitoring system was used to measure temperatures and velocities of spray droplets ejected from the guns. On the other hand, for the latter, qualities of coating layers on substrates—namely, surface roughness, atomic composition, hardness, adhesive strength, and porosity—were characterized. Then, these coating qualities were discussed with respect to the measured temperatures and velocities of spray droplets, which revealed novel features in the coatings that have not been seen before, such as atomic composition and hardness strongly dependent on temperature and environments of droplets towards the substrates, and porosity on velocity of droplets impinging onto the substrates.
      PubDate: 2017-02-16
      DOI: 10.3390/coatings7020027
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 28: Improving the Wear Resistance of Moulds for
           the Injection of Glass Fibre–Reinforced Plastics Using PVD Coatings: A
           Comparative Study

    • Authors: Francisco Silva, Rui Martinho, Maria Andrade, António Baptista, Ricardo Alexandre
      First page: 28
      Abstract: It is well known that injection of glass fibre–reinforced plastics (GFRP) causes abrasive wear in moulds’ cavities and runners. Physical vapour deposition (PVD) coatings are intensively used to improve the wear resistance of different tools, also being one of the most promising ways to increase the moulds’ lifespan, mainly when used with plastics strongly reinforced with glass fibres. This work compares four different thin, hard coatings obtained using the PVD magnetron sputtering process: TiAlN, TiAlSiN, CrN/TiAlCrSiN and CrN/CrCN/DLC. The first two are monolayer coatings while the last ones are nanostructured and consist of multilayer systems. In order to carry out the corresponding tribological characterization, two different approaches were selected: A laboratorial method, using micro-abrasion wear tests based on a ball-cratering configuration, and an industrial mode, analysing the wear resistance of the coated samples when inserted in a plastic injection mould. As expected, the wear phenomena are not equivalent and the results between micro-abrasion and industrial tests are not similar due to the different means used to promote the abrasion. The best wear resistance performance in the laboratorial wear tests was attained by the TiAlN monolayer coating while the best performance in the industrial wear tests was obtained by the CrN/TiAlCrSiN nanostructured multilayer coating.
      PubDate: 2017-02-16
      DOI: 10.3390/coatings7020028
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 29: Assessment on the Effects of ZnO and Coated

    • Authors: Antonella Marra, Gennaro Rollo, Sossio Cimmino, Clara Silvestre
      First page: 29
      Abstract: This paper compares the properties of iPP based composites and PLA based biocomposites using 5% of ZnO particles or ZnO particles coated with stearic acid as filler. In particular, the effect of coating on the UV stability, thermostability, mechanical, barrier, and antibacterial properties of the polymer matrix were compared and related to the dispersion and distribution of the loads in the polymer matrix and the strength of the adhesion between the matrix and the particles. This survey demonstrated that, among the reported systems, iPP/5%ZnOc and PLA/5%ZnO films are the most suitable active materials for potential application in the active food packaging field.
      PubDate: 2017-02-17
      DOI: 10.3390/coatings7020029
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 30: Effects of Rare Earth Elements on Properties
           of Ni-Base Superalloy Powders and Coatings

    • Authors: Chunlian Hu, Shanglin Hou
      First page: 30
      Abstract: NiCrMoY alloy powders were prepared using inert gas atomization by incorporation of rare earth elements, such as Mo, Nb, and Y into Ni60A powders, the coatings were sprayed by oxy-acetylene flame spray and then remelted with high-frequency induction. The morphologies, hollow particle ratio, particle-size distribution, apparent density, flowability, and the oxygen content of the NiCrMoY alloy powders were investigated, and the microstructure and hardness of the coatings were evaluated by optical microscopy (OM). Due to incorporation of the rare earth elements of Mo, Nb, or Y, the majority of the NiCrMoY alloy particles are near-spherical, the minority of which have small satellites, the surface of the particles is smoother and hollow particles are fewer, the particles exhibit larger apparent density and lower flowability than those of particles without incorporation, i.e., Ni60A powders, and particle-size distribution exhibits a single peak and fits normal distribution. The microstructure of the NiCrMoY alloy coatings exhibits finer structure and Rockwell hardness HRC of 60–63 in which the bulk- and needle-like hard phases are formed.
      PubDate: 2017-02-16
      DOI: 10.3390/coatings7020030
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 31: Microstructural Changes of Al Hot-Dipped P91
           Steel during High-Temperature Oxidation

    • Authors: Muhammad Abro, Dong Lee
      First page: 31
      Abstract: The 9Cr-1Mo steel (ASTM P91) was hot-dip aluminized, and its microstructural changes during oxidation were studied. Before oxidation, the coating consisted of (Al-rich topcoat containing a small amount of Al5Fe2 and Al13Fe4)/(Al13Fe4-rich, Al13Fe4-containing alloy layer)/(Al5Fe2 alloy layer containing a small amount of Al9Cr4 precipitates), from the surface. During oxidation at 700–900 °C for 20–100 h, Al diffused inward and the substrate elements migrated outward to broaden and soften the coating, and also to transform (high Al)-Fe intermetallics to (low Al)-Fe intermetallics. The phases in the coating progressively transformed during oxidation as follows; (Al-rich topcoat)/(Al5Fe2–rich, Al13Fe4-containing alloy layer)/(Al5Fe2 alloy layer)→(α-Al2O3 scale)/(Al13Fe4–rich, Al5Fe2-containing layer)/(Al5Fe2 layer)/(AlFe interlayer)→(α-Al2O3 scale)/(AlFe–rich, Al5Fe2-containing layer)/(AlFe layer)/(AlFe3 layer))→((α-Al2O3, Fe2O3)-mixed scale)/(AlFe3 layer)/(Fe(Al) layer) from the surface. As the oxidation progressed, the scale changed from α-Al2O3 to the (α-Al2O3, Fe2O3)-mixture, which provided the necessary oxidation resistance.
      PubDate: 2017-02-17
      DOI: 10.3390/coatings7020031
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 32: Damping Optimization of Hard-Coating Thin
           Plate by the Modified Modal Strain Energy Method

    • Authors: Wei Sun, Rong Liu
      First page: 32
      Abstract: Due to the medium and small damping characteristics of the hard coating compared with viscoelastic materials, the classical modal strain energy (CMSE) method cannot be applied to the prediction of damping characteristics of hard-coating composite structure directly. In this study, the CMSE method was modified in order to be suitable for this calculation, and then the damping optimization of the hard-coating thin plate was carried out. First, the solution formula of modified modal strain energy (MMSE) method was derived and the relevant calculation procedure was proposed. Then, based on the principle that depositing the hard coating on the locations where modal strain energy is higher, the damping optimization method and procedure were presented. Next, a cantilever thin plate coated with Mg-Al hard coating was taken as an example to demonstrate the solution of the modal damping parameters for the composite plate. Finally, the optimization of coating location was studied according to the proposed method for the cantilever thin plate, and the effect of the coating area on the damping characteristics of hard-coating plate was also discussed.
      PubDate: 2017-02-17
      DOI: 10.3390/coatings7020032
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 33: Static and Dynamic Magnetization Investigation
           in Permalloy Electrodeposited onto High Resistive N-Type Silicon

    • Authors: Kenedy Freitas, José Toledo, Leandro Figueiredo, Paulo Morais, Jorlandio Felix, Clodoaldo de Araujo
      First page: 33
      Abstract: The present study reports on the development of permalloy thin films obtained by electrodeposition onto low-doped n-type silicon substrates. While changing from non-percolated clusters into percolated thin films upon increasing the electrodeposition time, the static and dynamic magnetic properties of the as-obtained structures were investigated. We found the experimental magnetic results to be in very good agreement with the simulations performed by solving the Landau-Lifshitz for the dynamics of the magnetic moment. For short electrodeposition times we found the static and dynamic magnetization behavior of the as-formed nanoclusters evidencing vortex magnetization with random chirality and polarization, which is explained in terms of dipolar interaction minimization. Indeed, it is herein emphasized that recent applications of ferromagnetic materials in silicon-based spintronic devices, such as logic and bipolar magnetic transistors and magnetic memories, have revived the possible utilization of low cost and simple electrodeposition techniques for the development of these upcoming hetero-nanostructured devices.
      PubDate: 2017-02-20
      DOI: 10.3390/coatings7020033
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 34: SnS Thin Film Solar Cells: Perspectives and

    • Authors: Simone Di Mare, Daniele Menossi, Andrei Salavei, Elisa Artegiani, Fabio Piccinelli, Arun Kumar, Gino Mariotto, Alessandro Romeo
      First page: 34
      Abstract: Thin film solar cells have reached commercial maturity and extraordinarily high efficiency that make them competitive even with the cheaper Chinese crystalline silicon modules. However, some issues (connected with presence of toxic and/or rare elements) are still limiting their market diffusion. For this reason new thin film materials, such as Cu2ZnSnS4 or SnS, have been introduced so that expensive In and Te, and toxic elements Se and Cd, are substituted, respectively, in CuInGaSe2 and CdTe. To overcome the abundance limitation of Te and In, in recent times new thin film materials, such as Cu2ZnSnS4 or SnS, have been investigated. In this paper we analyze the limitations of SnS deposition in terms of reproducibility and reliability. SnS deposited by thermal evaporation is analyzed by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and atomic force microscopy. The raw material is also analyzed and a different composition is observed according to the different number of evaporation (runs). The sulfur loss represents one of the major challenges of SnS solar cell technology.
      PubDate: 2017-02-22
      DOI: 10.3390/coatings7020034
      Issue No: Vol. 7, No. 2 (2017)
  • Coatings, Vol. 7, Pages 8: Assessment of Environmental Performance of TiO2
           Nanoparticles Coated Self-Cleaning Float Glass

    • Authors: Martina Pini, Erika Cedillo González, Paolo Neri, Cristina Siligardi, Anna Ferrari
      First page: 8
      Abstract: In recent years, superhydrophilic and photocatalytic self-cleaning nanocoatings have been widely used in the easy-to-clean surfaces field. In the building sector, self-cleaning glass was one of the first nanocoating applications. These products are based on the photocatalytic property of a thin layer of titanium dioxide (TiO2) nanoparticles deposited on the surface of any kind of common glass. When exposed to UV radiation, TiO2 nanoparticles react with the oxygen and water molecules adsorbed on their surface to produce radicals leading to oxidative species. These species are able to reduce or even eliminate airborne pollutants and organic substances deposited on the material’s surface. To date, TiO2 nanoparticles’ benefits have been substantiated; however, their ecological and human health risks are still under analysis. The present work studies the ecodesign of the industrial scale-up of TiO2 nanoparticles self-cleaning coated float glass production performed by the life cycle assessment (LCA) methodology and applies new human toxicity indicators to the impact assessment stage. Production, particularly the TiO2 nanoparticle application, is the life cycle phase most contributing to the total damage. According to the ecodesign approach, the production choices carried out have exacerbated environmental burdens.
      PubDate: 2017-01-12
      DOI: 10.3390/coatings7010008
      Issue No: Vol. 7, No. 1 (2017)
  • Coatings, Vol. 7, Pages 9: Thickness Measurement Methods for Physical
           Vapor Deposited Aluminum Coatings in Packaging Applications: A Review

    • Authors: Martina Lindner, Markus Schmid
      First page: 9
      Abstract: The production of barrier packaging materials, e.g., for food, by physical vapor deposition (PVD) of inorganic coatings such as aluminum on polymer substrates is an established and well understood functionalization technique today. In order to achieve a sufficient barrier against gases, a coating thickness of approximately 40 nm aluminum is necessary. This review provides a holistic overview of relevant methods commonly used in the packaging industry as well as in packaging research for determining the aluminum coating thickness. The theoretical background, explanation of methods, analysis and effects on measured values, limitations, and resolutions are provided. In industrial applications, quartz micro balances (QCM) and optical density (OD) are commonly used for monitoring thickness homogeneity. Additionally, AFM (atomic force microscopy), electrical conductivity, eddy current measurement, interference, and mass spectrometry (ICP-MS) are presented as more packaging research related methods. This work aims to be used as a guiding handbook regarding the thickness measurement of aluminum coatings for packaging technologists working in the field of metallization.
      PubDate: 2017-01-14
      DOI: 10.3390/coatings7010009
      Issue No: Vol. 7, No. 1 (2017)
  • Coatings, Vol. 7, Pages 10: Photocatalytic Properties of Doped TiO2
           Coatings Deposited Using Reactive Magnetron Sputtering

    • Authors: Parnia Navabpour, Kevin Cooke, Hailin Sun
      First page: 10
      Abstract: Mechanically robust photocatalytic titanium oxide coatings can be deposited using reactive magnetron sputtering. In this article, we investigate the effect of doping on the activity of reactively sputtered TiO2. Silver, copper and stainless steel targets were used to co-deposit the dopants. The films were characterised using XRD, SEM and EDX. Adhesion and mechanical properties were evaluated using scratch testing and nano-indentation, respectively, and confirmed that the coatings had excellent adhesion to the stainless steel substrate. All coatings showed superhydrophilicity under UV irradiation. A methylene blue degradation test was used to assess their photocatalytic activity and showed all coatings to be photoactive to varying degrees, dependent upon the dopant, its concentration and the resulting coating structure. The results demonstrated that copper doping at low concentrations resulted in the coatings with the highest photocatalytic activity under both UV and fluorescent light irradiation.
      PubDate: 2017-01-17
      DOI: 10.3390/coatings7010010
      Issue No: Vol. 7, No. 1 (2017)
  • Coatings, Vol. 7, Pages 11: Regenerable Antibacterial Cotton Fabric by
           Plasma Treatment with Dimethylhydantoin: Antibacterial Activity against S.

    • Authors: Chang-E. Zhou, Chi-wai Kan, Jukka Matinlinna, James Tsoi
      First page: 11
      Abstract: This study examined the influence of variables in a finishing process for making cotton fabric with regenerable antibacterial properties against Staphylococcus aureus (S. aureus). 5,5-dimethylhydantoin (DMH) was coated onto cotton fabric by a pad-dry-plasma-cure method. Sodium hypochlorite was used for chlorinating the DMH coated fabric in order to introduce antibacterial properties. An orthogonal array testing strategy (OATS) was used in the finishing process for finding the optimum treatment conditions. After finishing, UV-Visible spectroscopy, Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR) were employed to characterise the properties of the treated cotton fabric, including the concentration of chlorine, morphological properties, and functional groups. The results show that cotton fabric coated with DMH followed by plasma treatment and chlorination can inhibit S. aureus and that the antibacterial property is regenerable.
      PubDate: 2017-01-18
      DOI: 10.3390/coatings7010011
      Issue No: Vol. 7, No. 1 (2017)
  • Coatings, Vol. 7, Pages 12: On the Durability and Wear Resistance of
           Transparent Superhydrophobic Coatings

    • Authors: Ilker Bayer
      First page: 12
      Abstract: Transparent liquid repellent coatings with exceptional wear and abrasion resistance are very demanding to fabricate. The most important reason for this is the fact that majority of the transparent liquid repellent coatings have so far been fabricated by nanoparticle assembly on surfaces in the form of films. These films or coatings demonstrate relatively poor substrate adhesion and rubbing induced wear resistance compared to polymer-based transparent hydrophobic coatings. However, recent advances reported in the literature indicate that considerable progress has now been made towards formulating and applying transparent, hydrophobic and even oleophobic coatings onto various substrates which can withstand certain degree of mechanical abrasion. This is considered to be very promising for anti-graffiti coatings or treatments since they require resistance to wear abrasion. Therefore, this review intends to highlight the state-of-the-art on materials and techniques that are used to fabricate wear resistant liquid repellent transparent coatings so that researchers can assess various aptitudes and limitations related to translating some of these technologies to large scale stain repellent outdoor applications.
      PubDate: 2017-01-18
      DOI: 10.3390/coatings7010012
      Issue No: Vol. 7, No. 1 (2017)
  • Coatings, Vol. 7, Pages 13: Numerical and Experimental Investigation on
           the Spray Coating Process Using a Pneumatic Atomizer: Influences of
           Operating Conditions and Target Geometries

    • Authors: Qiaoyan Ye, Karlheinz Pulli
      First page: 13
      Abstract: This paper presents a numerical simulation of the spray painting process using a pneumatic atomizer with the help of a computational fluid dynamics code. The droplet characteristics that are necessary for the droplet trajectory calculation were experimentally investigated using different shaping air flow rates. It was found that the droplet size distribution depends on both the atomizing and the shaping air flow rate. An injection model for creating the initial droplet conditions is necessary for the spray painting simulation. An approach for creating these initial conditions has been proposed, which takes different operating conditions into account and is suitable for practical applications of spray coating simulation using spray guns. Further, tests on complicated targets and complex alignments of the atomizer have been carried out to verify this numerical approach. The results confirm the applicability and reliability of the chosen method for the painting process.
      PubDate: 2017-01-18
      DOI: 10.3390/coatings7010013
      Issue No: Vol. 7, No. 1 (2017)
  • Coatings, Vol. 7, Pages 14: Combustion Synthesis during Flame Spraying
           (“CAFSY”) for the Production of Catalysts on Substrates

    • Authors: Galina Xanthopoulou, Amalia Marinou, Konstantinos Karanasios, George Vekinis
      First page: 14
      Abstract: Combustion-assisted flame spraying (“CAFSY”) has been used to produce catalytically active nickel aluminide coatings on ceramic substrates. Their catalytic activity was studied in CO2 (dry) reforming of methane, which is particularly significant for environmental protection as well as production of synthesis gas (CO + H2). By varying the CAFSY processing parameters, it is possible to obtain a range of Ni–Al alloys with various ratios of catalytically active phases on the substrate. The influence of the number of coating layers and the type of substrate on the final catalyst composition and on the catalytic activity of the CAFSY coatings was studied and is presented here. The morphology and microstructure of the composite coatings were determined by scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) elemental analysis, X-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET) specific area analysis. Catalytic tests for dry reforming of methane were carried out using crushed pellets from the coatings at temperatures of 750–900 °C, and gas chromatography showed that methane conversion approached 88% whereas that of carbon dioxide reached 100%. The H2/CO ratio in the synthesis gas produced by the reaction varied from about 0.7 to over 1.2, depending on the catalyst and substrate type and testing temperature.
      PubDate: 2017-01-20
      DOI: 10.3390/coatings7010014
      Issue No: Vol. 7, No. 1 (2017)
  • Coatings, Vol. 7, Pages 15: MHD Flow and Heat Transfer Analysis in the
           Wire Coating Process Using Elastic-Viscous

    • Authors: Zeeshan Khan, Rehan Shah, Saeed Islam, Hamid Jan, Bilal Jan, Haroon-Ur Rasheed, Aurangzeeb Khan
      First page: 15
      Abstract: The most important plastic resins used for wire coating are polyvinyl chloride (PVC), nylon, polysulfone, and low-/high-density polyethylene (LDPE/HDPE). In this article, the coating process is performed using elastic-viscous fluid as a coating material for wire coating in a pressure type coating die. The elastic-viscous fluid is electrically conducted in the presence of an applied magnetic field. The governing non-linear equations are modeled and then solved analytically by utilizing an Adomian decomposition method (ADM). The convergence of the series solution is established. The results are also verified by Optimal Homotopy Asymptotic Method (OHAM). The effect of different emerging parameters such as non-Newtonian parameters α and β, magnetic parameter Mand the Brinkman number Br on solutions (velocity and temperature profiles) are discussed through several graphs. Additionally, the current results are compared with published work already available.
      PubDate: 2017-01-22
      DOI: 10.3390/coatings7010015
      Issue No: Vol. 7, No. 1 (2017)
  • Coatings, Vol. 7, Pages 16: Investigation of the Corrosion Behavior of
           Electroless Ni-P Coating in Flue Gas Condensate

    • Authors: Hejie Yang, Yimin Gao, Weichao Qin
      First page: 16
      Abstract: The corrosion behavior of Ni-P coating deposited on 3003 aluminum alloy in flue gas condensate was investigated by electrochemical approaches. The results indicated that nitrite acted as a corrosion inhibitor. The inhibiting effect of nitrite was reduced in solutions containing sulfate or nitrate. Chloride and sulfate accelerated the corrosion of Ni-P coatings greatly. This can provide important information for the researchers to develop special Ni-P coatings with high corrosion resistance in the flue gas condensate.
      PubDate: 2017-01-19
      DOI: 10.3390/coatings7010016
      Issue No: Vol. 7, No. 1 (2017)
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