Pub Date : 2021-03-24DOI: 10.3390/COATINGS11040370
B. Tiss, Y. Moualhi, N. Bouguila, M. Kraini, S. Alaya, C. Croitoru, I. Ghiuta, D. Cristea, D. Pătroi, C. Moura, L. Cunha
Spray pyrolysis was used to deposit indium sulfide (In2S3) films, with or without silver doping. The films are polycrystalline, and the inclusion of Ag in the In2S3 structure leads to the formation of a solid solution, with the crystallite size of the order of tens of nanometers. In2S3 films exhibit a semiconductive behavior, and the incorporation of Ag leads to an increase of the charge carrier concentration, enhancing the electrical conductivity of the films. The small polaron hopping mechanism, deduced by the fittings according to the double Jonscher variation, explains the evolution of the direct current (dc) conductivity at high temperature of the Ag-doped indium sulfide. From impedance spectroscopy, it was found that the doped film presents dielectric relaxation, and Nyquist diagrams indicate the importance of the grain and the grain boundaries’ contributions to the transport phenomena. The physical characteristics of the films have an influence on the photocatalytic performance, achieving photodegradation efficiency above 80% (85.5% in the case of Ag doping), and on the antibacterial activity. The obtained results indicate that indium sulfide films are good candidates for environmental and biological applications, confirming a multifunctional nature.
{"title":"Influence of the Physical Properties on the Antibacterial and Photocatalytic Behavior of Ag-Doped Indium Sulfide Film Deposited by Spray Pyrolysis","authors":"B. Tiss, Y. Moualhi, N. Bouguila, M. Kraini, S. Alaya, C. Croitoru, I. Ghiuta, D. Cristea, D. Pătroi, C. Moura, L. Cunha","doi":"10.3390/COATINGS11040370","DOIUrl":"https://doi.org/10.3390/COATINGS11040370","url":null,"abstract":"Spray pyrolysis was used to deposit indium sulfide (In2S3) films, with or without silver doping. The films are polycrystalline, and the inclusion of Ag in the In2S3 structure leads to the formation of a solid solution, with the crystallite size of the order of tens of nanometers. In2S3 films exhibit a semiconductive behavior, and the incorporation of Ag leads to an increase of the charge carrier concentration, enhancing the electrical conductivity of the films. The small polaron hopping mechanism, deduced by the fittings according to the double Jonscher variation, explains the evolution of the direct current (dc) conductivity at high temperature of the Ag-doped indium sulfide. From impedance spectroscopy, it was found that the doped film presents dielectric relaxation, and Nyquist diagrams indicate the importance of the grain and the grain boundaries’ contributions to the transport phenomena. The physical characteristics of the films have an influence on the photocatalytic performance, achieving photodegradation efficiency above 80% (85.5% in the case of Ag doping), and on the antibacterial activity. The obtained results indicate that indium sulfide films are good candidates for environmental and biological applications, confirming a multifunctional nature.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83500451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-24DOI: 10.3390/COATINGS11040373
Zheng-Xin Yan, Haoran Peng, K. Yuan, Xin Zhang
Yb2O3-Gd2O3-Y2O3 co-doped ZrO2 (YGYZ) is considered to be a promising material in thermal barrier coating (TBC) applications. In this study, 2Yb2O3–2Gd2O3–6Y2O3–90ZrO2 (mol.%) (10YGYZ) feedstock candidates for air plasma spraying (APS) were prepared by calcination of agglomerated powders at 1100, 1200, 1300, 1400, and 1500 °C for 3 h, respectively. Incomplete solid solution was observed in calcined powders at 1100, 1200 and 1300 °C, and the 1500 °C calcined powder exhibited poor flowability due to intense sintering effect. The 1400 °C calcined powders were eventually determined to be the optimized feedstock for proper phase structure (cubic phase), great flowability, suitable apparent density and particle size distribution, etc. 10YGYZ TBCs with the optimized feedstock were prepared by APS, exhibiting pure c phase and good chemical uniformity. Controllable preparation of coatings with different porosity (i.e., 7%–9% and 12%–14%) was realized by stand-off distance adjustment.
{"title":"Optimization of Yb2O3-Gd2O3-Y2O3 Co-Doped ZrO2 Agglomerated and Calcined Powders for Air Plasma Spraying","authors":"Zheng-Xin Yan, Haoran Peng, K. Yuan, Xin Zhang","doi":"10.3390/COATINGS11040373","DOIUrl":"https://doi.org/10.3390/COATINGS11040373","url":null,"abstract":"Yb2O3-Gd2O3-Y2O3 co-doped ZrO2 (YGYZ) is considered to be a promising material in thermal barrier coating (TBC) applications. In this study, 2Yb2O3–2Gd2O3–6Y2O3–90ZrO2 (mol.%) (10YGYZ) feedstock candidates for air plasma spraying (APS) were prepared by calcination of agglomerated powders at 1100, 1200, 1300, 1400, and 1500 °C for 3 h, respectively. Incomplete solid solution was observed in calcined powders at 1100, 1200 and 1300 °C, and the 1500 °C calcined powder exhibited poor flowability due to intense sintering effect. The 1400 °C calcined powders were eventually determined to be the optimized feedstock for proper phase structure (cubic phase), great flowability, suitable apparent density and particle size distribution, etc. 10YGYZ TBCs with the optimized feedstock were prepared by APS, exhibiting pure c phase and good chemical uniformity. Controllable preparation of coatings with different porosity (i.e., 7%–9% and 12%–14%) was realized by stand-off distance adjustment.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85360532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-23DOI: 10.3390/COATINGS11030367
Z. Safari, P. Ding, J. Nakasha, S. F. Yusoff
Tomato Lycopersicon esculentum Mill. is one of the most cultivated and widely consumed vegetables in the world. However, it is very susceptible to the infection initiated by Fusariumoxysporum fruit rot, which shortens post-harvest life and thus reduces market value. This disease can be regulated appropriately by the application of synthetic fungicides. However, chemical fungicides constitute a serious health risk, and have harmful environment effects and increase disease resistance, even when microbes are dead. Hence, to overcome this problem, chitosan and vanillin, which have antimicrobial bioactive properties against the growth of microorganisms, could be an alternative to disease control, while maintaining fruit quality and prolonging shelf life. The aim of this research was to evaluate the antimicrobial activity of chitosan and vanillin towards the inoculate pathogen and to investigate the effect of chitosan and vanillin coating in vivo on Fusarium oxysporum fruit rot and defense-related enzymes (PAL, PPO and POD). Chitosan and vanillin in aqueous solutions, i.e., 0.5% chitosan + 10 mM vanillin, 1% chitosan + 10 mM vanillin, 1.5% chitosan + 10 mM vanillin, 0.5% chitosan + 15 mM vanillin, 1% chitosan + 15 mM vanillin and 1.5% chitosan + 15 mM vanillin, were used as edible coatings on tomatoes stored at 26 ± 2 °C and 60 ± 5 relative humidity. The result revealed 1.5% chitosan + 15 mM vanillin was able to control disease incidence by 70.84% and severity by 70%. These combinations of coatings were also able to retain phenylalanine ammonia-lyase (PAL), peroxidase activity (POD), and polyphenol oxidase (PPO) enzyme activities as well as prolong shelf life of tomatoes up to 15 days.
{"title":"Controlling Fusarium oxysporum Tomato Fruit Rot under Tropical Condition Using Both Chitosan and Vanillin","authors":"Z. Safari, P. Ding, J. Nakasha, S. F. Yusoff","doi":"10.3390/COATINGS11030367","DOIUrl":"https://doi.org/10.3390/COATINGS11030367","url":null,"abstract":"Tomato Lycopersicon esculentum Mill. is one of the most cultivated and widely consumed vegetables in the world. However, it is very susceptible to the infection initiated by Fusariumoxysporum fruit rot, which shortens post-harvest life and thus reduces market value. This disease can be regulated appropriately by the application of synthetic fungicides. However, chemical fungicides constitute a serious health risk, and have harmful environment effects and increase disease resistance, even when microbes are dead. Hence, to overcome this problem, chitosan and vanillin, which have antimicrobial bioactive properties against the growth of microorganisms, could be an alternative to disease control, while maintaining fruit quality and prolonging shelf life. The aim of this research was to evaluate the antimicrobial activity of chitosan and vanillin towards the inoculate pathogen and to investigate the effect of chitosan and vanillin coating in vivo on Fusarium oxysporum fruit rot and defense-related enzymes (PAL, PPO and POD). Chitosan and vanillin in aqueous solutions, i.e., 0.5% chitosan + 10 mM vanillin, 1% chitosan + 10 mM vanillin, 1.5% chitosan + 10 mM vanillin, 0.5% chitosan + 15 mM vanillin, 1% chitosan + 15 mM vanillin and 1.5% chitosan + 15 mM vanillin, were used as edible coatings on tomatoes stored at 26 ± 2 °C and 60 ± 5 relative humidity. The result revealed 1.5% chitosan + 15 mM vanillin was able to control disease incidence by 70.84% and severity by 70%. These combinations of coatings were also able to retain phenylalanine ammonia-lyase (PAL), peroxidase activity (POD), and polyphenol oxidase (PPO) enzyme activities as well as prolong shelf life of tomatoes up to 15 days.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84633068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-23DOI: 10.3390/COATINGS11030365
J. Suk, Sungwook Hong, G. Jang, N. Hwang
Non-classical crystallization, in which charged nanoparticles (NPs) are the building blocks of film growth, has been extensively studied in chemical vapor deposition (CVD). Here, the deposition behavior of silicon oxide films by the two-step growth process, where NPs are generated in the gas phase at high temperature and deposited as films at low temperature, was studied in the CVD process. Although we supplied SiH4, H2, and N2, the deposited film turned out to be silicon oxide, which is attributed to relatively poor vacuum. Also, silicon oxide NPs were captured on transmission electron microscopy (TEM) carbon membranes of a copper grid for 10 s under various conditions. When the quartz tube with a conical nozzle was used, the size of nanoparticles increased drastically with increasing processing time (or delay time) and porous films with a rough surface were deposited. When the quartz tube without a nozzle was used, however, the size did not increase much with increasing processing time and dense films with a smooth surface were deposited. These results suggest that the size of nanoparticles is an important parameter for the deposition of dense films for two-step growth at low temperatures.
{"title":"Two-Step Deposition of Silicon Oxide Films Using the Gas Phase Generation of Nanoparticles in the Chemical Vapor Deposition Process","authors":"J. Suk, Sungwook Hong, G. Jang, N. Hwang","doi":"10.3390/COATINGS11030365","DOIUrl":"https://doi.org/10.3390/COATINGS11030365","url":null,"abstract":"Non-classical crystallization, in which charged nanoparticles (NPs) are the building blocks of film growth, has been extensively studied in chemical vapor deposition (CVD). Here, the deposition behavior of silicon oxide films by the two-step growth process, where NPs are generated in the gas phase at high temperature and deposited as films at low temperature, was studied in the CVD process. Although we supplied SiH4, H2, and N2, the deposited film turned out to be silicon oxide, which is attributed to relatively poor vacuum. Also, silicon oxide NPs were captured on transmission electron microscopy (TEM) carbon membranes of a copper grid for 10 s under various conditions. When the quartz tube with a conical nozzle was used, the size of nanoparticles increased drastically with increasing processing time (or delay time) and porous films with a rough surface were deposited. When the quartz tube without a nozzle was used, however, the size did not increase much with increasing processing time and dense films with a smooth surface were deposited. These results suggest that the size of nanoparticles is an important parameter for the deposition of dense films for two-step growth at low temperatures.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74694094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-21DOI: 10.3390/COATINGS11030359
Jun-Mu Park, Myeong-hoon Lee, Seung-Hyo Lee
In this study, we tried to form the calcareous deposit films by the electrodeposition process. The uniform and compact calcareous deposit films were formed by electrodeposition process and their crystal structure and characteristics were analyzed and evaluated using various surface analytical techniques. The mechanism of formation for the calcareous deposit films could be confirmed and the role of magnesium was verified by experiments in artificial and natural seawater solutions. The highest amount of the calcareous deposit film was obtained at 5 A/m2 while current densities between 1–3 A/m2 facilitated the formation of the most uniform and dense layers. In addition, the adhesion characteristics were found to be the best at 3 A/m2. The excellent characteristics of the calcareous deposit films were obtained when the dense film of brucite-Mg(OH)2 and metastable aragonite-CaCO3 was formed in the appropriate ratio.
{"title":"Characteristics and Crystal Structure of Calcareous Deposit Films Formed by Electrodeposition Process in Artificial and Natural Seawater","authors":"Jun-Mu Park, Myeong-hoon Lee, Seung-Hyo Lee","doi":"10.3390/COATINGS11030359","DOIUrl":"https://doi.org/10.3390/COATINGS11030359","url":null,"abstract":"In this study, we tried to form the calcareous deposit films by the electrodeposition process. The uniform and compact calcareous deposit films were formed by electrodeposition process and their crystal structure and characteristics were analyzed and evaluated using various surface analytical techniques. The mechanism of formation for the calcareous deposit films could be confirmed and the role of magnesium was verified by experiments in artificial and natural seawater solutions. The highest amount of the calcareous deposit film was obtained at 5 A/m2 while current densities between 1–3 A/m2 facilitated the formation of the most uniform and dense layers. In addition, the adhesion characteristics were found to be the best at 3 A/m2. The excellent characteristics of the calcareous deposit films were obtained when the dense film of brucite-Mg(OH)2 and metastable aragonite-CaCO3 was formed in the appropriate ratio.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80431018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-21DOI: 10.3390/COATINGS11030358
Peng Zhao, Jun Li, R. Lei, B. Yuan, M. Xia, X. Li, Ying Zhang
AlCrCoNiFeCTax (x = 0, 0.5 and 1.0) high-entropy alloys coatings were synthesized on 45# steel by laser cladding. The microstructural evolution of the coatings with the change in x was analyzed in detail. The effect of Ta content on the wear behaviors of the coatings at different circumstances (in air and 3.5 wt.% NaCl solution) was especially highlighted. The microstructure presented the following change: equiaxed BCC (Body Centered Cubic) grains + fine MC (carbide, M = Al, Cr, Co and Ni) particles (x = 0) → equiaxed BCC grains + coarse TaC blocks + fine TaC particles (x = 0.5) → flower-like BCC grains + coarse TaC blocks + eutecticum (BCC + TaC) (x = 1.0). The average microhardness of the coatings demonstrated an upward tendency with increasing x due to the combination of the stronger solid solution and dispersion strengthening from the significant difference in atomic radius between Ta and Fe and the formation of TaC with an extremely high hardness. The wear rates of the coatings were gradually reduced both in air and in NaCl solution along with the increase in Ta content, which were lower than those of the substrate. The wear rates of the coatings with x = 0.5 and 1.0 in NaCl solution were slightly reduced by about 17% and 12% when compared with those in air. However, the values of the substrate and the coating without Ta in NaCl solution were sharply enhanced by 191% and 123% when compared with those in air. This indicated that the introduction of Ta contributed to the improvement in wear resistance both in air and in NaCl solution.
{"title":"Investigation into Microstructure, Wear Resistance in Air and NaCl Solution of AlCrCoNiFeCTax High-Entropy Alloy Coatings Fabricated by Laser Cladding","authors":"Peng Zhao, Jun Li, R. Lei, B. Yuan, M. Xia, X. Li, Ying Zhang","doi":"10.3390/COATINGS11030358","DOIUrl":"https://doi.org/10.3390/COATINGS11030358","url":null,"abstract":"AlCrCoNiFeCTax (x = 0, 0.5 and 1.0) high-entropy alloys coatings were synthesized on 45# steel by laser cladding. The microstructural evolution of the coatings with the change in x was analyzed in detail. The effect of Ta content on the wear behaviors of the coatings at different circumstances (in air and 3.5 wt.% NaCl solution) was especially highlighted. The microstructure presented the following change: equiaxed BCC (Body Centered Cubic) grains + fine MC (carbide, M = Al, Cr, Co and Ni) particles (x = 0) → equiaxed BCC grains + coarse TaC blocks + fine TaC particles (x = 0.5) → flower-like BCC grains + coarse TaC blocks + eutecticum (BCC + TaC) (x = 1.0). The average microhardness of the coatings demonstrated an upward tendency with increasing x due to the combination of the stronger solid solution and dispersion strengthening from the significant difference in atomic radius between Ta and Fe and the formation of TaC with an extremely high hardness. The wear rates of the coatings were gradually reduced both in air and in NaCl solution along with the increase in Ta content, which were lower than those of the substrate. The wear rates of the coatings with x = 0.5 and 1.0 in NaCl solution were slightly reduced by about 17% and 12% when compared with those in air. However, the values of the substrate and the coating without Ta in NaCl solution were sharply enhanced by 191% and 123% when compared with those in air. This indicated that the introduction of Ta contributed to the improvement in wear resistance both in air and in NaCl solution.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75702579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-19DOI: 10.3390/COATINGS11030354
Tim Tofan, R. Stonkus, R. Jasevičius
The aim of this research is to investigate related effect of dyeability to linen textiles related to different printing parameters. The study investigated the change in color characteristics when printing on linen fabrics with an inkjet MIMAKI Tx400-1800D printer with pigmented TP 250 inks. The dependence of color reproduction on linen fabrics on the number of print head passes, number of ink layers to be coated, linen fabric density, and different types of linen fabric was investigated. All this affects the quality of print and its mechanical properties. The change in color characteristics on different types of linen fabrics was determined experimentally. We determine at which print settings the most accurate color reproduction can be achieved on different linen fabrics. The difference between the highest and the lowest possible number of head passages was investigated. The possibilities of reproducing different linen fabric colors were determined.
{"title":"Investigation of Color Reproduction on Linen Fabrics when Printing with Mimaki TX400-1800D Inkjet with Pigment TP250 Dyes","authors":"Tim Tofan, R. Stonkus, R. Jasevičius","doi":"10.3390/COATINGS11030354","DOIUrl":"https://doi.org/10.3390/COATINGS11030354","url":null,"abstract":"The aim of this research is to investigate related effect of dyeability to linen textiles related to different printing parameters. The study investigated the change in color characteristics when printing on linen fabrics with an inkjet MIMAKI Tx400-1800D printer with pigmented TP 250 inks. The dependence of color reproduction on linen fabrics on the number of print head passes, number of ink layers to be coated, linen fabric density, and different types of linen fabric was investigated. All this affects the quality of print and its mechanical properties. The change in color characteristics on different types of linen fabrics was determined experimentally. We determine at which print settings the most accurate color reproduction can be achieved on different linen fabrics. The difference between the highest and the lowest possible number of head passages was investigated. The possibilities of reproducing different linen fabric colors were determined.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85577499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-17DOI: 10.3390/COATINGS11030341
Bochun Zhang, Kuiying Chen, N. Baddour
Residual stresses play an essential role in determining the failure mechanisms and life of an electron beam-physical vapour deposition thermal barrier coating (EB-PVD TBC) system. In this paper, a new transitional roughness model was proposed and applied to describe the interfacial roughness profile during thermal cycles. Finite element models were implemented to calculate residual stresses at specific positions close to the interface of TBCs using temperature process-dependent model parameters. Combining stresses evaluated at valleys of the topcoat (TC) and excessive sharp tip roughness profiles, positions where the maximum out-of-plane residual stresses occur were identified and used to explain possible cracking routes of EB-PVD TBCs as interfacial roughness evolves during thermal cycling.
{"title":"The Effect of Interfacial Roughness on Residual Stresses in Electron Beam-Physical Vapor Deposition of Thermal Barrier Coatings","authors":"Bochun Zhang, Kuiying Chen, N. Baddour","doi":"10.3390/COATINGS11030341","DOIUrl":"https://doi.org/10.3390/COATINGS11030341","url":null,"abstract":"Residual stresses play an essential role in determining the failure mechanisms and life of an electron beam-physical vapour deposition thermal barrier coating (EB-PVD TBC) system. In this paper, a new transitional roughness model was proposed and applied to describe the interfacial roughness profile during thermal cycles. Finite element models were implemented to calculate residual stresses at specific positions close to the interface of TBCs using temperature process-dependent model parameters. Combining stresses evaluated at valleys of the topcoat (TC) and excessive sharp tip roughness profiles, positions where the maximum out-of-plane residual stresses occur were identified and used to explain possible cracking routes of EB-PVD TBCs as interfacial roughness evolves during thermal cycling.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82205566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-16DOI: 10.3390/COATINGS11030338
Yanze Liu
Transparent superhydrophobic materials can be used in car glass, curtain walls, mobile phone screens, and other items. However, the hydrophobicity, transparency, and abrasion resistance of the transparent superhydrophobic coating are mutually restricted, and it is difficult to prepare transparent superhydrophobic coating with good performance. In this article, taking the mobile phone screen transparent coating as the research object, the inorganic silicon resin crystal coating as the main material, and the organic silicon resin as the binder and the hardness regulator, with the addition of the hydrophobically modifying nano silica particles, a high-transparent, wear-resistant, and superhydrophobic coating is researched. Experiments showed that when the composition mass ratio of SJ-32F resin to 9825 resin is 9:1 and the mass ratio of modified nano silica is 1.7%, the coating has a hardness of 3H–4H suitable for mobile phone screens, the contact angle of the coating can reach more than 150°, the rolling angle is less than 10°, and the light transmittance of the coating remains high at 91–95%. The cross-hatch adhesion strength of the coating reaches 5B, and the average adhesion strength measured by the adhesion pull tester is about 5.4 MPa. When the rubbing times reached 100, the light transmittance of the coating remained above 80%, and the contact angle remained basically unchanged.
{"title":"Research on a Superhydrophobic Coating of Highly Transparent Wear-Resistant Inorganic/Organic Silicon Composite Resin","authors":"Yanze Liu","doi":"10.3390/COATINGS11030338","DOIUrl":"https://doi.org/10.3390/COATINGS11030338","url":null,"abstract":"Transparent superhydrophobic materials can be used in car glass, curtain walls, mobile phone screens, and other items. However, the hydrophobicity, transparency, and abrasion resistance of the transparent superhydrophobic coating are mutually restricted, and it is difficult to prepare transparent superhydrophobic coating with good performance. In this article, taking the mobile phone screen transparent coating as the research object, the inorganic silicon resin crystal coating as the main material, and the organic silicon resin as the binder and the hardness regulator, with the addition of the hydrophobically modifying nano silica particles, a high-transparent, wear-resistant, and superhydrophobic coating is researched. Experiments showed that when the composition mass ratio of SJ-32F resin to 9825 resin is 9:1 and the mass ratio of modified nano silica is 1.7%, the coating has a hardness of 3H–4H suitable for mobile phone screens, the contact angle of the coating can reach more than 150°, the rolling angle is less than 10°, and the light transmittance of the coating remains high at 91–95%. The cross-hatch adhesion strength of the coating reaches 5B, and the average adhesion strength measured by the adhesion pull tester is about 5.4 MPa. When the rubbing times reached 100, the light transmittance of the coating remained above 80%, and the contact angle remained basically unchanged.","PeriodicalId":22482,"journal":{"name":"THE Coatings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89835193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-15DOI: 10.3390/COATINGS11030332
U. Coscia, A. Longo, M. Palomba, A. Sorrentino, G. Barucca, A. Di Bartolomeo, F. Urban, G. Ambrosone, G. Carotenuto
Morphological, structural, and thermoresistive properties of films deposited on low-density polyethylene (LDPE) substrates are investigated for possible application in flexible electronics. Scanning and transmission electron microscopy analyses, and X-ray diffraction measurements show that the films consist of overlapped graphite nanoplatelets (GNP) each composed on average of 41 graphene layers. Differential scanning calorimetry and dynamic-mechanical-thermal analysis indicate that irreversible phase transitions and large variations of mechanical parameters in the polymer substrates can be avoided by limiting the temperature variations between −40 and 40 °C. Electrical measurements performed in such temperature range reveal that the resistance of GNP films on LDPE substrates increases as a function of the temperature, unlike the behavior of graphite-based materials in which the temperature coefficient of resistance is negative. The explanation is given by the strong influence of the thermal expansion properties of the LDPE substrates on the thermo-resistive features of GNP coating films. The results show that, narrowing the temperature range from 20 to 40 °C, the GNP on LDPE samples can work as temperature sensors having linear temperature-resistance relationship, while keeping constant the temperature and applying mechanical strains in the 0–4.2 × 10−3 range, they can operate as strain gauges with a gauge factor of about 48.
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