Pub Date : 2024-08-08DOI: 10.3390/coatings14081009
M. Kohl, Karolína Boštíková, S. Šlang, E. Schmidová, A. Kalendová
Within this study, the influence of particles of different types, natures, and sizes on the mechanical and corrosion resistance of pigmented systems containing spherical zinc was studied. For this study, prominent representatives from the group of transition metal dichalcogenides (MoS2, WS2), layered transition metal oxides (MoO3, WO3), and other semiconductor materials (ZnS and ZnO) were used. The layered ultra-thin structure of these particles was predisposed to provide enhanced mechanical and anti-corrosion performance. The mechanical properties of the studied coatings were tested using standardized mechanical tests, while the anti-corrosion performance of these coatings was studied using standardized cyclic corrosion tests and the linear polarization electrochemical technique. The results of the experimental techniques bring completely original knowledge about the action of these pigments in paint systems pigmented with zinc. The results of experimental techniques have shown enhancement and an increase in both mechanical and anti-corrosion performance when using these special types of inorganic pigments. In particular, with organic coatings pigmented with MoO3, there was an increase in mechanical resistance mainly due to its morphology and layered structure. In addition, a significant enhancement of the anti-corrosion efficiency was noted for this type of organic coating due to the enhancement of individual types of action mechanisms typical and proven for zinc-pigmented systems. These original findings can be used in the search for possibilities to reduce the zinc content in zinc-pigmented organic coatings. This partial replacement of zinc particles leads not only to a reduction in the zinc content in the system but also to a significant strengthening of the mechanical resistance and an increase in the corrosion efficiency of the system.
{"title":"Use of 2D Sulfide and Oxide Compounds as Functional Semiconducting Pigments in Protective Organic Coatings Containing Zinc Dust","authors":"M. Kohl, Karolína Boštíková, S. Šlang, E. Schmidová, A. Kalendová","doi":"10.3390/coatings14081009","DOIUrl":"https://doi.org/10.3390/coatings14081009","url":null,"abstract":"Within this study, the influence of particles of different types, natures, and sizes on the mechanical and corrosion resistance of pigmented systems containing spherical zinc was studied. For this study, prominent representatives from the group of transition metal dichalcogenides (MoS2, WS2), layered transition metal oxides (MoO3, WO3), and other semiconductor materials (ZnS and ZnO) were used. The layered ultra-thin structure of these particles was predisposed to provide enhanced mechanical and anti-corrosion performance. The mechanical properties of the studied coatings were tested using standardized mechanical tests, while the anti-corrosion performance of these coatings was studied using standardized cyclic corrosion tests and the linear polarization electrochemical technique. The results of the experimental techniques bring completely original knowledge about the action of these pigments in paint systems pigmented with zinc. The results of experimental techniques have shown enhancement and an increase in both mechanical and anti-corrosion performance when using these special types of inorganic pigments. In particular, with organic coatings pigmented with MoO3, there was an increase in mechanical resistance mainly due to its morphology and layered structure. In addition, a significant enhancement of the anti-corrosion efficiency was noted for this type of organic coating due to the enhancement of individual types of action mechanisms typical and proven for zinc-pigmented systems. These original findings can be used in the search for possibilities to reduce the zinc content in zinc-pigmented organic coatings. This partial replacement of zinc particles leads not only to a reduction in the zinc content in the system but also to a significant strengthening of the mechanical resistance and an increase in the corrosion efficiency of the system.","PeriodicalId":10520,"journal":{"name":"Coatings","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141927848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.3390/coatings14081003
Jinzhe Deng, Tingting Ding, Xiaoxing Yan
In order to prepare chitosan-coated pomelo peel flavonoid microcapsules with antibacterial properties, chitosan was used as the wall material for the purpose of coating the core material, pomelo peel flavonoids. The pH of the microcapsule crosslinking reaction was 7.5, the mass ratio of the microcapsule core material to the wall material was 1:1, and the concentration of the emulsifier was 1%. The microcapsules obtained under these preparation conditions exhibited superior performance, morphology, and dispersion. Additionally, the yield and coating rates were recorded at 22% and 50%, respectively. To prepare the paint film, the microcapsules were added into the coatings at varying concentrations of 0%, 3.0%, 6.0%, 9.0%, 12.0%, and 15.0%. The antibacterial efficacy of the paint film for both bacteria was progressively enhanced with the incorporation of microcapsules. The antibacterial efficacy against Staphylococcus aureus was observed to be higher than that against Escherichia coli. As the content of microcapsules increased, the color difference in the paint film increased, the gloss loss rate increased, and the light transmission rate reduced. The tensile property and elongation at break reduced, and the roughness increased. At a microcapsule content of 6.0%, the paint film exhibited superior overall performance, with an antibacterial efficacy against Escherichia coli and Staphylococcus aureus of 46.3% and 56.7%, respectively. The color difference was 38.58. The gloss loss rate was 41.0%, the light transmission rate was 90.4%, and the paint film exhibited a large elastic region, with an elongation at break of 21.5% and a roughness of 1.46 μm.
{"title":"Optimization of Preparation Process for Chitosan-Coated Pomelo Peel Flavonoid Microcapsules and Its Effect on Waterborne Paint Film Properties","authors":"Jinzhe Deng, Tingting Ding, Xiaoxing Yan","doi":"10.3390/coatings14081003","DOIUrl":"https://doi.org/10.3390/coatings14081003","url":null,"abstract":"In order to prepare chitosan-coated pomelo peel flavonoid microcapsules with antibacterial properties, chitosan was used as the wall material for the purpose of coating the core material, pomelo peel flavonoids. The pH of the microcapsule crosslinking reaction was 7.5, the mass ratio of the microcapsule core material to the wall material was 1:1, and the concentration of the emulsifier was 1%. The microcapsules obtained under these preparation conditions exhibited superior performance, morphology, and dispersion. Additionally, the yield and coating rates were recorded at 22% and 50%, respectively. To prepare the paint film, the microcapsules were added into the coatings at varying concentrations of 0%, 3.0%, 6.0%, 9.0%, 12.0%, and 15.0%. The antibacterial efficacy of the paint film for both bacteria was progressively enhanced with the incorporation of microcapsules. The antibacterial efficacy against Staphylococcus aureus was observed to be higher than that against Escherichia coli. As the content of microcapsules increased, the color difference in the paint film increased, the gloss loss rate increased, and the light transmission rate reduced. The tensile property and elongation at break reduced, and the roughness increased. At a microcapsule content of 6.0%, the paint film exhibited superior overall performance, with an antibacterial efficacy against Escherichia coli and Staphylococcus aureus of 46.3% and 56.7%, respectively. The color difference was 38.58. The gloss loss rate was 41.0%, the light transmission rate was 90.4%, and the paint film exhibited a large elastic region, with an elongation at break of 21.5% and a roughness of 1.46 μm.","PeriodicalId":10520,"journal":{"name":"Coatings","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141926340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.3390/coatings14081005
Xiaotian Liu, Winnie Wing-Yee Shum, J. Tsoi
This study aims to study the formation quality of the film of dental silanes. Two dental silanes, 3-methacryloxyproyltrimethoxysilane (MPS) and 3-acryloyloxypropyltrimethoxysilane (ACPS), were deposited on the silica glass-equivalent model surface (i.e., n-type silicon(100) wafer) by varying the deposition time (5 h and 22 h). The film quality was then evaluated by ellipsometry, surface contact angle (CA) and surface free energy (SFE), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) in survey and high-resolution modes on Si2p, O1s and C1s. Ellipsometry confirmed that both silanes at the two different deposition times would produce 0.85–1.22 nm thick self-assembled monolayer on the silicon wafer surface. While the water CA of silanized surfaces (60.7–71.5°) was larger than the surface without silane (29.6°), the SFE values of all silanes (40.0–44.5 mN/m) were slightly less than that of the wafer surface (46.3 mN/m). AFM revealed that the MPS with 22 h silanization yielded a significantly higher roughness (0.597 μm) than other groups (0.254–0.297 μm). High-resolution XPS on C1s identified a prominent peak at 288.5 eV, which corresponds to methacrylate O-C*=O, i.e., the silane monolayer is extended fully in the vertical direction, while others are in defect states. This study proves that different dental silanes under various dipping times yield different chemical qualities of the film even if they look thin physically.
{"title":"Ultra-Structural Surface Characteristics of Dental Silane Monolayers","authors":"Xiaotian Liu, Winnie Wing-Yee Shum, J. Tsoi","doi":"10.3390/coatings14081005","DOIUrl":"https://doi.org/10.3390/coatings14081005","url":null,"abstract":"This study aims to study the formation quality of the film of dental silanes. Two dental silanes, 3-methacryloxyproyltrimethoxysilane (MPS) and 3-acryloyloxypropyltrimethoxysilane (ACPS), were deposited on the silica glass-equivalent model surface (i.e., n-type silicon(100) wafer) by varying the deposition time (5 h and 22 h). The film quality was then evaluated by ellipsometry, surface contact angle (CA) and surface free energy (SFE), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) in survey and high-resolution modes on Si2p, O1s and C1s. Ellipsometry confirmed that both silanes at the two different deposition times would produce 0.85–1.22 nm thick self-assembled monolayer on the silicon wafer surface. While the water CA of silanized surfaces (60.7–71.5°) was larger than the surface without silane (29.6°), the SFE values of all silanes (40.0–44.5 mN/m) were slightly less than that of the wafer surface (46.3 mN/m). AFM revealed that the MPS with 22 h silanization yielded a significantly higher roughness (0.597 μm) than other groups (0.254–0.297 μm). High-resolution XPS on C1s identified a prominent peak at 288.5 eV, which corresponds to methacrylate O-C*=O, i.e., the silane monolayer is extended fully in the vertical direction, while others are in defect states. This study proves that different dental silanes under various dipping times yield different chemical qualities of the film even if they look thin physically.","PeriodicalId":10520,"journal":{"name":"Coatings","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141928608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The research on and application of electric fields to promote the rapid infiltration of ions into cement concrete have been widely explored. Still, there are few studies on the migration of sulfate ions using electric fields. In this paper, a new test method is designed using the principle of electric fields, that is, to accelerate the attack of sulfate into concrete under the action of the electric field, to test the resistance of concrete to sulfate attack. By testing different water–cement ratios, different pulse frequencies, different ages, and different soaking environments, the influence of the electric field on the sulfate resistance of concrete was analyzed. The results show that the compressive strength of concrete in a sulfate attack environment is smaller than that of conventional attack and water immersion environment when the water–cement ratio is 0.3, 0.4, and 0.5 under the action of the electric field and increases with the increase of water in the water–cement ratio. Compared with a 14 day test, the compressive strength of concrete in a sulfate attack environment decreased by 1.9%, 8.6%, and 2.9%, respectively, at 28 days, which was faster than that of conventional attack and water immersion. The compressive strength of the concrete in the sulfate attack environment during the full immersion test and the semi-immersion test is smaller than that of the conventional attack and water immersion, and the semi-immersion test method is more obvious than the full immersion test method. The microscopic morphology of the test group, the water group, and the solution group were compared. From the microscopic morphology comparison, it can be seen that the electric field accelerates the diffusion of sulfate ions into the cement concrete and accelerates the reaction of sulfate ions with the relevant components in the cement concrete. Given the demand for concrete to resist sulfate attack under the action of the electric field, developing new and efficient protective materials is an important research direction. At present, the market lacks protective materials specifically for such an attack environment. This paper provides the theoretical basis and technical support for improving the effectiveness of concrete surface protection technology and engineering practices.
{"title":"Study on the Attack of Concrete by External Sulfate under Electric Fields","authors":"Huanqin Liu, Nuoqi Shi, Kaizhao Han, Xu Fu, Yuexin Fang","doi":"10.3390/coatings14081008","DOIUrl":"https://doi.org/10.3390/coatings14081008","url":null,"abstract":"The research on and application of electric fields to promote the rapid infiltration of ions into cement concrete have been widely explored. Still, there are few studies on the migration of sulfate ions using electric fields. In this paper, a new test method is designed using the principle of electric fields, that is, to accelerate the attack of sulfate into concrete under the action of the electric field, to test the resistance of concrete to sulfate attack. By testing different water–cement ratios, different pulse frequencies, different ages, and different soaking environments, the influence of the electric field on the sulfate resistance of concrete was analyzed. The results show that the compressive strength of concrete in a sulfate attack environment is smaller than that of conventional attack and water immersion environment when the water–cement ratio is 0.3, 0.4, and 0.5 under the action of the electric field and increases with the increase of water in the water–cement ratio. Compared with a 14 day test, the compressive strength of concrete in a sulfate attack environment decreased by 1.9%, 8.6%, and 2.9%, respectively, at 28 days, which was faster than that of conventional attack and water immersion. The compressive strength of the concrete in the sulfate attack environment during the full immersion test and the semi-immersion test is smaller than that of the conventional attack and water immersion, and the semi-immersion test method is more obvious than the full immersion test method. The microscopic morphology of the test group, the water group, and the solution group were compared. From the microscopic morphology comparison, it can be seen that the electric field accelerates the diffusion of sulfate ions into the cement concrete and accelerates the reaction of sulfate ions with the relevant components in the cement concrete. Given the demand for concrete to resist sulfate attack under the action of the electric field, developing new and efficient protective materials is an important research direction. At present, the market lacks protective materials specifically for such an attack environment. This paper provides the theoretical basis and technical support for improving the effectiveness of concrete surface protection technology and engineering practices.","PeriodicalId":10520,"journal":{"name":"Coatings","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141926162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.3390/coatings14081007
Yojana J. P. Carreón, Angel A. Pereyra Zarate, Alondra E. Pérez Sánchez, Orlando Díaz-Hernández, J. González-Gutiérrez
Foliar fertilization, an effective agricultural practice, involves the application of nutrients directly through droplets on plant leaves. The mechanisms of mass transport and deposition that arise from the drying of a drop determine the distribution of mass on a surface. Understanding these processes is crucial for optimizing foliar fertilization, ensuring even nutrient distribution, and improving crop yields and quality. This study experimentally investigates deposit formation from the evaporation of fertilizer droplets in various configurations: sessile, vertical, and pendant. We explored the effects of initial droplet volume, vapor pressure, and sorbitol presence on the final deposit morphology. The results reveal distinctive morphological patterns. Sessile drops exhibit two types of deposits—central crystal accumulation with fibrous structures or entirely fibrous structures. In contrast, vertical drops display two zones—fibrous structures at the bottom and small aggregates at the top. On the other hand, pendant drops predominantly feature intertwined crystals with peripheral fibrous structures. We found that high vapor pressures (RH = 60%) inhibit deposit formation within 72 h. Furthermore, the study measures relative evaporation time, showing that sessile droplets exhibit the longest evaporation times, followed by vertical and pendant droplets. Texture analysis, based on GLCM entropy, reveals that deposits generated under low vapor pressure (RH = 20%) show no significant differences in their entropy values, regardless of the droplet configuration and its initial volume. However, at intermediate vapor pressure (RH = 40%), entropy values vary significantly with droplet volume and configuration, being higher in sessile drops and lower in vertical ones. Additionally, we investigated the impact of sorbitol on the coating of sessile fertilizer droplets. We find that configurational entropy decreases exponentially with sorbitol concentration, inducing a morphological transition from fibrous structures to dispersed small aggregates. These findings highlight the complexity of pattern formation in fertilizer deposits and their potential implications for optimizing surface coating processes.
{"title":"Surface Coating with Foliar Fertilizers","authors":"Yojana J. P. Carreón, Angel A. Pereyra Zarate, Alondra E. Pérez Sánchez, Orlando Díaz-Hernández, J. González-Gutiérrez","doi":"10.3390/coatings14081007","DOIUrl":"https://doi.org/10.3390/coatings14081007","url":null,"abstract":"Foliar fertilization, an effective agricultural practice, involves the application of nutrients directly through droplets on plant leaves. The mechanisms of mass transport and deposition that arise from the drying of a drop determine the distribution of mass on a surface. Understanding these processes is crucial for optimizing foliar fertilization, ensuring even nutrient distribution, and improving crop yields and quality. This study experimentally investigates deposit formation from the evaporation of fertilizer droplets in various configurations: sessile, vertical, and pendant. We explored the effects of initial droplet volume, vapor pressure, and sorbitol presence on the final deposit morphology. The results reveal distinctive morphological patterns. Sessile drops exhibit two types of deposits—central crystal accumulation with fibrous structures or entirely fibrous structures. In contrast, vertical drops display two zones—fibrous structures at the bottom and small aggregates at the top. On the other hand, pendant drops predominantly feature intertwined crystals with peripheral fibrous structures. We found that high vapor pressures (RH = 60%) inhibit deposit formation within 72 h. Furthermore, the study measures relative evaporation time, showing that sessile droplets exhibit the longest evaporation times, followed by vertical and pendant droplets. Texture analysis, based on GLCM entropy, reveals that deposits generated under low vapor pressure (RH = 20%) show no significant differences in their entropy values, regardless of the droplet configuration and its initial volume. However, at intermediate vapor pressure (RH = 40%), entropy values vary significantly with droplet volume and configuration, being higher in sessile drops and lower in vertical ones. Additionally, we investigated the impact of sorbitol on the coating of sessile fertilizer droplets. We find that configurational entropy decreases exponentially with sorbitol concentration, inducing a morphological transition from fibrous structures to dispersed small aggregates. These findings highlight the complexity of pattern formation in fertilizer deposits and their potential implications for optimizing surface coating processes.","PeriodicalId":10520,"journal":{"name":"Coatings","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141928188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-08DOI: 10.3390/coatings14081006
Xuanzheng Wang, Jie Liu, Yingfan Liu, Wentao Li, Yanming Chen, Bing-Na Yang
High-entropy nitride AlCrNbSiTiN coatings were deposited by RF magnetron sputtering at different bias voltages. The structure, mechanical properties and water vapor corrosion resistance of the coatings were systematically studied. The coatings exhibit a face-centered cubic (FCC) structure, while achieving a hardness up to 35.8 GPa. The main wear mechanisms of the coatings are adhesive wear and oxidation wear. After 200 h of water vapor corrosion, the content of O in the coatings is 4.30 at.%.
在不同的偏置电压下，通过射频磁控溅射沉积了高熵氮化物 AlCrNbSiTiN 涂层。对涂层的结构、机械性能和耐水蒸气腐蚀性能进行了系统研究。涂层呈现出面心立方（FCC）结构，硬度高达 35.8 GPa。涂层的主要磨损机制是粘着磨损和氧化磨损。经过 200 小时的水蒸气腐蚀后，涂层中的 O 含量为 4.30%。
{"title":"Structure, Mechanical Properties and Water Vapor Corrosion Resistance of AlCrNbSiTiN High-Entropy Nitride Coatings Deposited by RF Magnetron Sputtering","authors":"Xuanzheng Wang, Jie Liu, Yingfan Liu, Wentao Li, Yanming Chen, Bing-Na Yang","doi":"10.3390/coatings14081006","DOIUrl":"https://doi.org/10.3390/coatings14081006","url":null,"abstract":"High-entropy nitride AlCrNbSiTiN coatings were deposited by RF magnetron sputtering at different bias voltages. The structure, mechanical properties and water vapor corrosion resistance of the coatings were systematically studied. The coatings exhibit a face-centered cubic (FCC) structure, while achieving a hardness up to 35.8 GPa. The main wear mechanisms of the coatings are adhesive wear and oxidation wear. After 200 h of water vapor corrosion, the content of O in the coatings is 4.30 at.%.","PeriodicalId":10520,"journal":{"name":"Coatings","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141929324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-07DOI: 10.3390/coatings14080996
Dianying Chen, Christopher Dambra
Higher operating temperatures for gas turbine engines require highly durable thermal barrier coatings (TBCs) with improved insulation properties. A suspension plasma spray process (SPS) had been developed for the deposition of columnar-structured TBCs. SPS columnar TBCs are normally achieved at a short standoff distance (50.0 mm–75.0 mm), which is not practical when coating complex-shaped engine hardware since the plasma torch may collide with the components being sprayed. Therefore, it is critical to develop SPS columnar TBCs at longer standoff distances. In this work, a commercially available pressure-based suspension delivery system was used to deliver the suspension to the plasma jet, and a high-enthalpy TriplexPro-210 plasma torch was used for the SPS coating deposition. Suspension injection pressure was optimized to maximize the number of droplets injected into the hot plasma core and achieving the best particle-melting states and deposition efficiency. The highest deposition efficiency of 51% was achieved at 0.34 MPa injection pressure with a suspension flow rate of 31.0 g/min. With the optimized process parameters, 1000 μm thick columnar-structured SPS 8 wt% Y2O3-stabilized ZrO2 (8YSZ) TBCs were successfully developed at a standoff distance of 100.0 mm. The SPS TBCs have a columnar width between 100 μm and 300 μm with a porosity of ~22%. Furnace cycling tests at 1125 °C showed the SPS columnar TBCs had an average life of 1012 cycles, which is ~2.5 times that of reference air-plasma-sprayed dense vertically cracked TBCs with the same coating thickness. The superior durability of the SPS columnar TBCs can be attributed to the high-strain-tolerant microstructure. SEM cross-section characterization indicated the failure of the SPS TBCs occurred at the ceramic top coat and thermally grown oxide (TGO) interface.
{"title":"Thick Columnar-Structured Thermal Barrier Coatings Using the Suspension Plasma Spray Process","authors":"Dianying Chen, Christopher Dambra","doi":"10.3390/coatings14080996","DOIUrl":"https://doi.org/10.3390/coatings14080996","url":null,"abstract":"Higher operating temperatures for gas turbine engines require highly durable thermal barrier coatings (TBCs) with improved insulation properties. A suspension plasma spray process (SPS) had been developed for the deposition of columnar-structured TBCs. SPS columnar TBCs are normally achieved at a short standoff distance (50.0 mm–75.0 mm), which is not practical when coating complex-shaped engine hardware since the plasma torch may collide with the components being sprayed. Therefore, it is critical to develop SPS columnar TBCs at longer standoff distances. In this work, a commercially available pressure-based suspension delivery system was used to deliver the suspension to the plasma jet, and a high-enthalpy TriplexPro-210 plasma torch was used for the SPS coating deposition. Suspension injection pressure was optimized to maximize the number of droplets injected into the hot plasma core and achieving the best particle-melting states and deposition efficiency. The highest deposition efficiency of 51% was achieved at 0.34 MPa injection pressure with a suspension flow rate of 31.0 g/min. With the optimized process parameters, 1000 μm thick columnar-structured SPS 8 wt% Y2O3-stabilized ZrO2 (8YSZ) TBCs were successfully developed at a standoff distance of 100.0 mm. The SPS TBCs have a columnar width between 100 μm and 300 μm with a porosity of ~22%. Furnace cycling tests at 1125 °C showed the SPS columnar TBCs had an average life of 1012 cycles, which is ~2.5 times that of reference air-plasma-sprayed dense vertically cracked TBCs with the same coating thickness. The superior durability of the SPS columnar TBCs can be attributed to the high-strain-tolerant microstructure. SEM cross-section characterization indicated the failure of the SPS TBCs occurred at the ceramic top coat and thermally grown oxide (TGO) interface.","PeriodicalId":10520,"journal":{"name":"Coatings","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-07DOI: 10.3390/coatings14080998
María Elena Sánchez Vergara, Eva Alejandra Santillán Esquivel, Ricardo Ballinas-Indilí, Octavio Lozada-Flores, René Miranda-Ruvalcaba, Cecilio Álvarez-Toledano
This work presents the synthesis of para-quinone methides (p-QMs), which were deposited as films using the high vacuum sublimation technique after being chemically characterized. The p-QMs films were characterized morphologically and structurally using scanning electron microscopy, atomic force microscopy, and X-ray diffraction. In addition, their optical behavior was studied by means of ultraviolet–visible spectroscopy, and the optical gaps obtained were in the range of 2.21–2.71 eV for indirect transitions, indicating the semiconductor behavior of the p-QMs. The above was verified through the manufacture and evaluation of the electrical behavior of rigid semiconductor devices, in which fluorine-doped tin oxide-coated glass slides (FTO) were used as an anode and substrate. Finally, as an original, ecological, and low-cost application, the FTO was replaced by substrates and anodes made from recycled Tetra Pak®, generating flexible semiconductor devices. Although the electrical current transported depends on the type of p-QMs, the substituent in its structure, and the morphology, the kinds of substrate and anode also influence the type of electrical behavior of the device. This current–voltage study demonstrates that p-QM2 with 4-Cl-Ph as a radical, p-QM3 with 4-Et2N-Ph as a radical, and p-QM6 with 5-(1,3-benzodioxol) as a radical can be used in optoelectronics as semiconductor films.
{"title":"Organic Semiconductor Devices Fabricated with Recycled Tetra Pak®-Based Electrodes and para-Quinone Methides","authors":"María Elena Sánchez Vergara, Eva Alejandra Santillán Esquivel, Ricardo Ballinas-Indilí, Octavio Lozada-Flores, René Miranda-Ruvalcaba, Cecilio Álvarez-Toledano","doi":"10.3390/coatings14080998","DOIUrl":"https://doi.org/10.3390/coatings14080998","url":null,"abstract":"This work presents the synthesis of para-quinone methides (p-QMs), which were deposited as films using the high vacuum sublimation technique after being chemically characterized. The p-QMs films were characterized morphologically and structurally using scanning electron microscopy, atomic force microscopy, and X-ray diffraction. In addition, their optical behavior was studied by means of ultraviolet–visible spectroscopy, and the optical gaps obtained were in the range of 2.21–2.71 eV for indirect transitions, indicating the semiconductor behavior of the p-QMs. The above was verified through the manufacture and evaluation of the electrical behavior of rigid semiconductor devices, in which fluorine-doped tin oxide-coated glass slides (FTO) were used as an anode and substrate. Finally, as an original, ecological, and low-cost application, the FTO was replaced by substrates and anodes made from recycled Tetra Pak®, generating flexible semiconductor devices. Although the electrical current transported depends on the type of p-QMs, the substituent in its structure, and the morphology, the kinds of substrate and anode also influence the type of electrical behavior of the device. This current–voltage study demonstrates that p-QM2 with 4-Cl-Ph as a radical, p-QM3 with 4-Et2N-Ph as a radical, and p-QM6 with 5-(1,3-benzodioxol) as a radical can be used in optoelectronics as semiconductor films.","PeriodicalId":10520,"journal":{"name":"Coatings","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, based on the element powder metallurgy method, a new hybrid method is proposed, which firstly prepares TiAl-based deposit precursors by the cold spraying of mixed Ti and Al powders and then combines this with hot isostatic pressing to achieve the preparation of TiAl-based alloys. This paper explores the effects of deposition parameters on deposition efficiency and coating composition and investigates the evolution of the microstructure and properties of TiAl-based alloys by different hot isostatic pressing parameters. The results show that the prepared TiAl deposits are dense and free of microstructural defects; a high deposition efficiency (75%) and small deviation of coating composition (3 at %) are obtained under the spraying parameters of 5 MPa, 500 °C. The TiAl-based alloy with a dense microstructure can be prepared by controlling the parameters such as temperature, pressure, and heating rate of subsequent hot isostatic pressing.
本研究在元素粉末冶金方法的基础上，提出了一种新的混合方法，即首先通过冷喷Ti和Al混合粉末制备TiAl基沉积前驱体，然后将其与热等静压相结合，实现TiAl基合金的制备。本文探讨了沉积参数对沉积效率和涂层成分的影响，并研究了不同热等静压参数对 TiAl 基合金微观结构和性能的影响。结果表明，制备的 TiAl 沉积物致密且无微观结构缺陷；在 5 兆帕、500 ℃ 的喷涂参数下，沉积效率高（75%），涂层成分偏差小（3%）。通过控制后续热等静压的温度、压力和加热速率等参数，可以制备出具有致密微观结构的 TiAl 基合金。
{"title":"Preparation of Dense TiAl Intermetallics by Cold Spraying the Precursor–Hot Isostatic Pressing","authors":"Jiayan Ma, Xin Chu, Yingchun Xie, Jizhan Li, Min Liu, Jiwu Huang","doi":"10.3390/coatings14080999","DOIUrl":"https://doi.org/10.3390/coatings14080999","url":null,"abstract":"In this study, based on the element powder metallurgy method, a new hybrid method is proposed, which firstly prepares TiAl-based deposit precursors by the cold spraying of mixed Ti and Al powders and then combines this with hot isostatic pressing to achieve the preparation of TiAl-based alloys. This paper explores the effects of deposition parameters on deposition efficiency and coating composition and investigates the evolution of the microstructure and properties of TiAl-based alloys by different hot isostatic pressing parameters. The results show that the prepared TiAl deposits are dense and free of microstructural defects; a high deposition efficiency (75%) and small deviation of coating composition (3 at %) are obtained under the spraying parameters of 5 MPa, 500 °C. The TiAl-based alloy with a dense microstructure can be prepared by controlling the parameters such as temperature, pressure, and heating rate of subsequent hot isostatic pressing.","PeriodicalId":10520,"journal":{"name":"Coatings","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-07DOI: 10.3390/coatings14081000
Yanfeng Miao, Xuefei Gao, Tianming Miao, Wei Xu
This study on oriented strand board (OSB) wood doors with veneer as the door leaf aimed to investigate consumers’ preference for visual–tactile elements of OSB. First, we utilized the questionnaire and interview methods to extract specific elements as experimental variables for this study. Then, through subjective evaluation experiments and eye-movement experiments, as well as correlation analyses of the experimental results, we explored the relationship between the slice size, gloss, and color of oriented strand boards and consumers’ visual preferences and summarized the eye-movement indexes that can represent consumers’ aesthetic evaluation of the visual elements of oriented strand boards. Unidirectional haptic experiments analyzed the relationships between the slice size, gloss, and roughness of the oriented strand boards and consumers’ haptic preferences. The results showed that, visually, chip size and surface gloss had little effect on people’s subjective aesthetic evaluations of oriented strand-board wood doors. At the same time, the quantitative mean pupil diameter could represent consumers’ aesthetic evaluations of oriented strand boards. Regarding haptics, the size of the wood chips on the surface of the oriented strand-board specimens did not significantly correlate with participants’ haptic preferences. All participants’ tactile preferences for the unpainted specimens were positively correlated with the fineness of sanding. The visual and tactile effects presented on the surface of an object are essential factors that influence the perception of a material. Oriented strand board (OSB) has excellent advantages in providing a healthy and environmentally friendly living environment, so exploring the visual and tactile perception of OSB from the consumer’s point of view plays a vital role in promoting the use of OSB. The visual–tactile experimental results and the conclusions drawn from the analysis in this study can enable OSB to provide more opinions and potential information from consumers for the design of OSB wooden doors under the premise of conforming to the actual production and meeting the quality standards so that the designed and produced OSB wooden doors can satisfy the users’ preferences based on safety and stability.
{"title":"A Study on the Visual and Tactile Perception of Oriented Strand Board Combined with Consumer-Preference Analysis","authors":"Yanfeng Miao, Xuefei Gao, Tianming Miao, Wei Xu","doi":"10.3390/coatings14081000","DOIUrl":"https://doi.org/10.3390/coatings14081000","url":null,"abstract":"This study on oriented strand board (OSB) wood doors with veneer as the door leaf aimed to investigate consumers’ preference for visual–tactile elements of OSB. First, we utilized the questionnaire and interview methods to extract specific elements as experimental variables for this study. Then, through subjective evaluation experiments and eye-movement experiments, as well as correlation analyses of the experimental results, we explored the relationship between the slice size, gloss, and color of oriented strand boards and consumers’ visual preferences and summarized the eye-movement indexes that can represent consumers’ aesthetic evaluation of the visual elements of oriented strand boards. Unidirectional haptic experiments analyzed the relationships between the slice size, gloss, and roughness of the oriented strand boards and consumers’ haptic preferences. The results showed that, visually, chip size and surface gloss had little effect on people’s subjective aesthetic evaluations of oriented strand-board wood doors. At the same time, the quantitative mean pupil diameter could represent consumers’ aesthetic evaluations of oriented strand boards. Regarding haptics, the size of the wood chips on the surface of the oriented strand-board specimens did not significantly correlate with participants’ haptic preferences. All participants’ tactile preferences for the unpainted specimens were positively correlated with the fineness of sanding. The visual and tactile effects presented on the surface of an object are essential factors that influence the perception of a material. Oriented strand board (OSB) has excellent advantages in providing a healthy and environmentally friendly living environment, so exploring the visual and tactile perception of OSB from the consumer’s point of view plays a vital role in promoting the use of OSB. The visual–tactile experimental results and the conclusions drawn from the analysis in this study can enable OSB to provide more opinions and potential information from consumers for the design of OSB wooden doors under the premise of conforming to the actual production and meeting the quality standards so that the designed and produced OSB wooden doors can satisfy the users’ preferences based on safety and stability.","PeriodicalId":10520,"journal":{"name":"Coatings","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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