Pub Date : 2024-04-26DOI: 10.3103/s1068375524020066
V. M. Kosenkov, L. P. Kolomiytseva
Abstract
Using the example of stamping a box-shaped part from high-strength sheet steel by a pulsed electro-hydraulic method, the limiting possibilities of its shaping, taking into account the springing of the material, are studied. The influence of the radius of the curvature and the shape of the surface of the corners of the part on the change in the structure of high-strength steel DP780 and the appearance of defects in it is determined. Relations between the radius of the curvature of the surface of the part and the thickness of the workpiece at which there are no defects in the structure of DP780 steel and the limiting possibilities of its deformation are achieved with minimal springing of the material are obtained.
{"title":"The Influence of Springing of High-Strength Steel DP780 on the Ultimate Possibilities of Its Formation during Electro-Hydraulic Stamping","authors":"V. M. Kosenkov, L. P. Kolomiytseva","doi":"10.3103/s1068375524020066","DOIUrl":"https://doi.org/10.3103/s1068375524020066","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Using the example of stamping a box-shaped part from high-strength sheet steel by a pulsed electro-hydraulic method, the limiting possibilities of its shaping, taking into account the springing of the material, are studied. The influence of the radius of the curvature and the shape of the surface of the corners of the part on the change in the structure of high-strength steel DP780 and the appearance of defects in it is determined. Relations between the radius of the curvature of the surface of the part and the thickness of the workpiece at which there are no defects in the structure of DP780 steel and the limiting possibilities of its deformation are achieved with minimal springing of the material are obtained.</p>","PeriodicalId":782,"journal":{"name":"Surface Engineering and Applied Electrochemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140804729","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 : 2024-04-26DOI: 10.3103/s1068375524020145
E. V. Yurchenko, G. V. Ghilețchii, S. A. Vatavu, V. I. Petrenko, D. Harea, C. Bubulinca, A. I. Dikusar
Abstract—
A combination of X-ray diffraction and X-ray fluorescence analysis has shown that the strengthened layer formed during electric spark alloying of 65G steel with a processing electrode made of the T15K6 hard alloy is a nanocrystalline material, the ratio of the crystalline and amorphous phases in which is achieved by changing the discharge energy. Since an increase in discharge energy leads to an increase in surface roughness and its amorphization, there is an optimal value of discharge energy at which maximum wear resistance of the resulting nanocomposites is achieved. At E = 0.2 J, the wear resistance of the hardened layer is 7–10 times higher than the wear resistance of the untreated surface.
摘要 结合 X 射线衍射和 X 射线荧光分析表明，用 T15K6 硬质合金制成的加工电极对 65G 钢进行电火花合金化时形成的强化层是一种纳米结晶材料，其中结晶相和非晶相的比例可通过改变放电能量来实现。由于放电能量的增加会导致表面粗糙度的增加及其非晶化，因此存在一个最佳放电能量值，在该值下所产生的纳米复合材料可达到最大耐磨性。在 E = 0.2 J 时，硬化层的耐磨性是未处理表面耐磨性的 7-10 倍。
{"title":"Composition, Structure, and Wear Resistance of Surface Nanostructures Obtained by Electric Spark Alloying of 65G Steel","authors":"E. V. Yurchenko, G. V. Ghilețchii, S. A. Vatavu, V. I. Petrenko, D. Harea, C. Bubulinca, A. I. Dikusar","doi":"10.3103/s1068375524020145","DOIUrl":"https://doi.org/10.3103/s1068375524020145","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract—</h3><p>A combination of X-ray diffraction and X-ray fluorescence analysis has shown that the strengthened layer formed during electric spark alloying of 65G steel with a processing electrode made of the T15K6 hard alloy is a nanocrystalline material, the ratio of the crystalline and amorphous phases in which is achieved by changing the discharge energy. Since an increase in discharge energy leads to an increase in surface roughness and its amorphization, there is an optimal value of discharge energy at which maximum wear resistance of the resulting nanocomposites is achieved. At <i>E</i> = 0.2 J, the wear resistance of the hardened layer is 7–10 times higher than the wear resistance of the untreated surface.</p>","PeriodicalId":782,"journal":{"name":"Surface Engineering and Applied Electrochemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140804699","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 : 2024-04-26DOI: 10.3103/s1068375524020078
Muhammad Natsir, Muhammad Nurdin, Zainal Rahmad Syah, Suryani Dyah Astuti, Thamrin Azis, La Ode Muhammad Zuhdi Mulkiyan, La Ode Agus Salim, Faizal Mustapa, Ahmad Zulfan, Maulidiyah Maulidiyah
Abstract
This research explores the heightened sensitivity of the electrochemical formaldehyde detection achieved by incorporating a modified graphene paste electrode with a titanium dioxide-silver (TiO2/Ag) composite (GTA). The G-TiO2 matrix was augmented with varying masses of silver modifiers, namely, 0.2, 0.4, 0.6, and 0.8 g, aiming to establish the most effective composition for formaldehyde detection. Characterization through scanning electron microscopy and energy-dispersive X-ray spectroscopy confirmed the material’s composition, revealing GTA electrode nanocomposites consisting of carbon, oxygen, titanium, and silver with the compositions of 77.05, 19.46, 2.39, and 1.11%, respectively. An electrochemical analysis was conducted to assess the efficacy of the developed electrode in a 1 M K3[Fe(CN)6] solution. Furthermore, a real sample testing was performed to evaluate the practical utility of the electrode gauging its efficiency through the calculation of percentage recovery before and after treatment. The GTA electrode with a 0.4 g Ag modifier exhibited the optimal performance, as evidenced by a Horwitz Ratio stability test result of 1.38% and a limit of detection of 0.0168 µg/L. This research highlights the promising potential of the GTA electrode for the precise and sensitive formaldehyde detection, particularly in processed food products.
摘要 本研究探讨了通过在改性石墨烯浆电极中加入二氧化钛-银（TiO2/Ag）复合材料（GTA）来提高电化学甲醛检测灵敏度的问题。在 G-TiO2 基质中添加了不同质量的银改性剂，分别为 0.2、0.4、0.6 和 0.8 克，目的是确定最有效的甲醛检测成分。通过扫描电子显微镜和能量色散 X 射线光谱分析确认了材料的成分，发现 GTA 电极纳米复合材料由碳、氧、钛和银组成，含量分别为 77.05%、19.46%、2.39% 和 1.11%。在 1 M K3[Fe(CN)6] 溶液中进行了电化学分析，以评估所开发电极的功效。此外，还进行了实际样品测试，通过计算处理前后的回收百分比来评估电极的实际效用。使用 0.4 g Ag 改性剂的 GTA 电极表现出最佳性能，其 Horwitz 比率稳定性测试结果为 1.38%，检测限为 0.0168 µg/L。这项研究凸显了 GTA 电极在精确灵敏地检测甲醛方面的巨大潜力，尤其是在加工食品中。
{"title":"Design and Fabrication of a High-Performance Sensor for Formaldehyde Detection Based on Graphene-TiO2/Ag Electrode","authors":"Muhammad Natsir, Muhammad Nurdin, Zainal Rahmad Syah, Suryani Dyah Astuti, Thamrin Azis, La Ode Muhammad Zuhdi Mulkiyan, La Ode Agus Salim, Faizal Mustapa, Ahmad Zulfan, Maulidiyah Maulidiyah","doi":"10.3103/s1068375524020078","DOIUrl":"https://doi.org/10.3103/s1068375524020078","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This research explores the heightened sensitivity of the electrochemical formaldehyde detection achieved by incorporating a modified graphene paste electrode with a titanium dioxide-silver (TiO<sub>2</sub>/Ag) composite (GTA). The G-TiO<sub>2</sub> matrix was augmented with varying masses of silver modifiers, namely, 0.2, 0.4, 0.6, and 0.8 g, aiming to establish the most effective composition for formaldehyde detection. Characterization through scanning electron microscopy and energy-dispersive X-ray spectroscopy confirmed the material’s composition, revealing GTA electrode nanocomposites consisting of carbon, oxygen, titanium, and silver with the compositions of 77.05, 19.46, 2.39, and 1.11%, respectively. An electrochemical analysis was conducted to assess the efficacy of the developed electrode in a 1 M K<sub>3</sub>[Fe(CN)<sub>6</sub>] solution. Furthermore, a real sample testing was performed to evaluate the practical utility of the electrode gauging its efficiency through the calculation of percentage recovery before and after treatment. The GTA electrode with a 0.4 g Ag modifier exhibited the optimal performance, as evidenced by a Horwitz Ratio stability test result of 1.38% and a limit of detection of 0.0168 µg/L. This research highlights the promising potential of the GTA electrode for the precise and sensitive formaldehyde detection, particularly in processed food products.</p>","PeriodicalId":782,"journal":{"name":"Surface Engineering and Applied Electrochemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140804706","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 : 2024-04-26DOI: 10.3103/s1068375524020029
M. I. Baranov
Abstract
A special case of equality of the conduction current density and the displacement current density in a homogeneous nonmagnetic conducting medium was used to consider the results of approximate calculation estimation of the relative permittivity εr of nonmagnetic conducting materials (metals and alloys), which are extensively used in electrical power engineering, electric power industry, and high-voltage pulse technology under the influence of variable (pulsed) electric currents and electromagnetic fields (EMF) with various amplitude–time parameters. It was demonstrated that, in the investigated case, at low frequencies f0 of conduction current and EMF (at a frequency on the order of 102 Hz) in the range of extremely low-frequency electromagnetic waves (EMW), the materials under consideration exhibit extremely high values of the electrophysical parameter εr (on the order of 1015). For extremely high frequencies f0 of current and EMF (at a frequency on the order of 5 × 1013 Hz) in the infrared range of EMW, these conducting materials are characterized by εr values on the order of 102–104, and in terms of the electrophysical parameter εr, they approach solid dielectrics and ferroelectrics.
{"title":"Calculation Estimation of the Relative Permittivity of Nonmagnetic Conducting Materials under the Action of Variable Conduction Current","authors":"M. I. Baranov","doi":"10.3103/s1068375524020029","DOIUrl":"https://doi.org/10.3103/s1068375524020029","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>A special case of equality of the conduction current density and the displacement current density in a homogeneous nonmagnetic conducting medium was used to consider the results of approximate calculation estimation of the relative permittivity ε<sub><i>r</i></sub> of nonmagnetic conducting materials (metals and alloys), which are extensively used in electrical power engineering, electric power industry, and high-voltage pulse technology under the influence of variable (pulsed) electric currents and electromagnetic fields (EMF) with various amplitude–time parameters. It was demonstrated that, in the investigated case, at low frequencies <i>f</i><sub>0</sub> of conduction current and EMF (at a frequency on the order of 10<sup>2</sup> Hz) in the range of extremely low-frequency electromagnetic waves (EMW), the materials under consideration exhibit extremely high values of the electrophysical parameter ε<sub><i>r</i></sub> (on the order of 10<sup>15</sup>). For extremely high frequencies <i>f</i><sub>0</sub> of current and EMF (at a frequency on the order of 5 × 10<sup>13</sup> Hz) in the infrared range of EMW, these conducting materials are characterized by ε<sub><i>r</i></sub> values on the order of 10<sup>2</sup>–10<sup>4</sup>, and in terms of the electrophysical parameter ε<sub><i>r</i></sub>, they approach solid dielectrics and ferroelectrics.</p>","PeriodicalId":782,"journal":{"name":"Surface Engineering and Applied Electrochemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140806716","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 : 2024-04-26DOI: 10.3103/s1068375524020030
A. A. Burkov, A. Yu. Bytsura
Abstract
Deposition of protective coatings improves the corrosion resistance and tribological behavior of the surfaces of metallic components. However, surface preparation prior to coating application increases the cost per unit area of the coating. Substrates made of St3 steel with surface roughness Ra ranging from 0.01 to 0.597 μm were prepared, including those with a layer of rust, and were subjected to electro-spark deposition of Cr–Fe–Cu coatings. The performed studies led to the conclusion that the initial surface roughness of St3 steel does not affect the nature of material deposition during the electro-spark alloying (ESA) and the structure of the deposited coatings. This is unequivocally confirmed by the data on heat resistance and tribological properties of the coatings. Electro-spark treatment can promote self-cleaning of the rust layer; however, complete elimination is not achieved, and large pores are formed in the coating. This significantly reduces the heat resistance and wear resistance of the coating.
{"title":"Influence of Substrate Surface Quality on Electro-Spark Alloying","authors":"A. A. Burkov, A. Yu. Bytsura","doi":"10.3103/s1068375524020030","DOIUrl":"https://doi.org/10.3103/s1068375524020030","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Deposition of protective coatings improves the corrosion resistance and tribological behavior of the surfaces of metallic components. However, surface preparation prior to coating application increases the cost per unit area of the coating. Substrates made of St3 steel with surface roughness <i>R</i><sub><i>a</i></sub> ranging from 0.01 to 0.597 μm were prepared, including those with a layer of rust, and were subjected to electro-spark deposition of Cr–Fe–Cu coatings. The performed studies led to the conclusion that the initial surface roughness of St3 steel does not affect the nature of material deposition during the electro-spark alloying (ESA) and the structure of the deposited coatings. This is unequivocally confirmed by the data on heat resistance and tribological properties of the coatings. Electro-spark treatment can promote self-cleaning of the rust layer; however, complete elimination is not achieved, and large pores are formed in the coating. This significantly reduces the heat resistance and wear resistance of the coating.</p>","PeriodicalId":782,"journal":{"name":"Surface Engineering and Applied Electrochemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140806663","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 : 2024-04-26DOI: 10.3103/s1068375524020091
K. D. Poluektova, S. A. Vasilkov, A. V. Slesarenko
Abstract
High voltage silicone insulators that are placed close to coastal marine areas have the problem of salt fog depositing on their surfaces in the form of conductive droplets. Under the influence of an electric field, those droplets initiate partial discharges, which leads to the degradation of the hydrophobic properties of silicone rubber. This phenomenon, in which droplets serve as the cause of partial discharges, has been studied in considerable detail elsewhere. However, it remains unclear whether the droplets themselves, as moisture-laden areas, affect the properties of silicone rubber. The current work is focused on studying the combined effect of an AC electric field (E = 17 kV/cm) and a 4% solution of sodium chloride on the water-repellent properties of silicone rubber in the absence of electrical discharges. The results of the study show that the influence of moisture and an electric field leads to slowing down the droplet runoff from the inclined sample of Powersil 310 rubber. An AC electric field did not have a noticeable effect on the rate of water runoff; the slowdown was due to the pre-treatment of the sample with the solution.
{"title":"Silicone Rubber Treatment with a Sodium Chloride Solution in the Presence of an Electric Field","authors":"K. D. Poluektova, S. A. Vasilkov, A. V. Slesarenko","doi":"10.3103/s1068375524020091","DOIUrl":"https://doi.org/10.3103/s1068375524020091","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>High voltage silicone insulators that are placed close to coastal marine areas have the problem of salt fog depositing on their surfaces in the form of conductive droplets. Under the influence of an electric field, those droplets initiate partial discharges, which leads to the degradation of the hydrophobic properties of silicone rubber. This phenomenon, in which droplets serve as the cause of partial discharges, has been studied in considerable detail elsewhere. However, it remains unclear whether the droplets themselves, as moisture-laden areas, affect the properties of silicone rubber. The current work is focused on studying the combined effect of an AC electric field (<i>E</i> = 17 kV/cm) and a 4% solution of sodium chloride on the water-repellent properties of silicone rubber in the absence of electrical discharges. The results of the study show that the influence of moisture and an electric field leads to slowing down the droplet runoff from the inclined sample of Powersil 310 rubber. An AC electric field did not have a noticeable effect on the rate of water runoff; the slowdown was due to the pre-treatment of the sample with the solution.</p>","PeriodicalId":782,"journal":{"name":"Surface Engineering and Applied Electrochemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140804667","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 : 2024-04-26DOI: 10.3103/s1068375524020133
A. P. Smirnov, O. V. Khvoshchan
Abstract—
Electric, energy, and hydrodynamic characteristics of high-voltage electrochemical explosion (HVECE) in confined liquid volumes were experimentally investigated with varying the charging voltage, the stored electrical energy, and the mass of the burnt exothermic mixture. A comparison with other methods of initiating an electrical discharge under similar conditions was conducted. The obtained results showed that HVECE allows achieving a high-voltage electrical discharge with low energy losses (less than 9%) and implementing an electrical breakdown mode close to aperiodic. It was found that HVECE generates compression waves with amplitudes up to 37% and specific impulse up to 45% higher (at a charging voltage of 25 kV and above) than in the case of electrical explosion of an initiating metallic conductor under identical initial conditions. It was revealed that increasing the charging voltage leads to a linear increase in the amplitude and specific impulse of the generated compression wave. A comprehensive analysis of the dependences of energy and hydrodynamic characteristics showed that both the stored electrical energy and the interrelation of electrical parameters of the discharge circuit with the mass of the burning exothermic mixture have a significant influence on the formation of the specific impulse of the compression wave in HVECE, determining the shape of the discharge characteristics.
{"title":"Experimental Studies of Hydrodynamic and Energy Characteristics of High-Voltage Electrochemical Explosion in Confined Volumes of Liquid","authors":"A. P. Smirnov, O. V. Khvoshchan","doi":"10.3103/s1068375524020133","DOIUrl":"https://doi.org/10.3103/s1068375524020133","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">\u0000<b>Abstract</b>—</h3><p>Electric, energy, and hydrodynamic characteristics of high-voltage electrochemical explosion (HVECE) in confined liquid volumes were experimentally investigated with varying the charging voltage, the stored electrical energy, and the mass of the burnt exothermic mixture. A comparison with other methods of initiating an electrical discharge under similar conditions was conducted. The obtained results showed that HVECE allows achieving a high-voltage electrical discharge with low energy losses (less than 9%) and implementing an electrical breakdown mode close to aperiodic. It was found that HVECE generates compression waves with amplitudes up to 37% and specific impulse up to 45% higher (at a charging voltage of 25 kV and above) than in the case of electrical explosion of an initiating metallic conductor under identical initial conditions. It was revealed that increasing the charging voltage leads to a linear increase in the amplitude and specific impulse of the generated compression wave. A comprehensive analysis of the dependences of energy and hydrodynamic characteristics showed that both the stored electrical energy and the interrelation of electrical parameters of the discharge circuit with the mass of the burning exothermic mixture have a significant influence on the formation of the specific impulse of the compression wave in HVECE, determining the shape of the discharge characteristics.</p>","PeriodicalId":782,"journal":{"name":"Surface Engineering and Applied Electrochemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140804808","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 : 2024-04-26DOI: 10.3103/s106837552402011x
O. B. Shmychkova, V. A. Knysh, T. V. Luk’yanenko, A. B. Velichenko
Abstract
The influence of the synthesis conditions on the surface morphology, phase composition, and electrocatalytic activity of materials in oxygen and hydrogen evolution reactions was investigated. For instance, the slopes in the potential verses the logarithm of the current density dependencies during oxygen evolution were 221 and 109 mV/dec for TiO2 nanotubes and platinum-coated layers, respectively. In the latter case, small deviations may be attributed to the structural heterogeneity of the material or the developed surface of the coating. As for pristine TiO2 nanotubes, an atypical Tafel slope was observed, almost twice the theoretical value, indicating the presence of a semiconductor component in the electrode capacitance. Studies showed that the materials are n-type semiconductors. The cathodic polarization stage leads to the formation of titanium suboxides in the nanotube recovery phase, contributing to an increase in the material electrical conductivity. This also allows for the creation of a porous developed surface matrix for the electrodeposition of catalytic metal layers. Tafel slopes were calculated for the investigated materials in the hydrogen evolution reaction. For TiO2 nanotubes, a slope of 175 mV/dec was observed. The material surface was partially blocked by hydroxides, resulting in a low number of active centers for the hydrogen evolution, and the polarization curve had a steep slope. In the case of TiO2 nanotubes coated with a platinum layer, a high number of cationic vacancies in the matrix and a deficit of oxygen ions facilitated the mobility of platinum atoms, leading to the emergence of a large number of active centers for the hydrogen evolution. As a result, the Tafel slope of the polarization curve was found to be 30 mV/dec.
{"title":"Physicochemical and Electrochemical Properties of Materials Based on Titanium Suboxides","authors":"O. B. Shmychkova, V. A. Knysh, T. V. Luk’yanenko, A. B. Velichenko","doi":"10.3103/s106837552402011x","DOIUrl":"https://doi.org/10.3103/s106837552402011x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The influence of the synthesis conditions on the surface morphology, phase composition, and electrocatalytic activity of materials in oxygen and hydrogen evolution reactions was investigated. For instance, the slopes in the potential verses the logarithm of the current density dependencies during oxygen evolution were 221 and 109 mV/dec for TiO<sub>2</sub> nanotubes and platinum-coated layers, respectively. In the latter case, small deviations may be attributed to the structural heterogeneity of the material or the developed surface of the coating. As for pristine TiO<sub>2</sub> nanotubes, an atypical Tafel slope was observed, almost twice the theoretical value, indicating the presence of a semiconductor component in the electrode capacitance. Studies showed that the materials are n-type semiconductors. The cathodic polarization stage leads to the formation of titanium suboxides in the nanotube recovery phase, contributing to an increase in the material electrical conductivity. This also allows for the creation of a porous developed surface matrix for the electrodeposition of catalytic metal layers. Tafel slopes were calculated for the investigated materials in the hydrogen evolution reaction. For TiO<sub>2</sub> nanotubes, a slope of 175 mV/dec was observed. The material surface was partially blocked by hydroxides, resulting in a low number of active centers for the hydrogen evolution, and the polarization curve had a steep slope. In the case of TiO<sub>2</sub> nanotubes coated with a platinum layer, a high number of cationic vacancies in the matrix and a deficit of oxygen ions facilitated the mobility of platinum atoms, leading to the emergence of a large number of active centers for the hydrogen evolution. As a result, the Tafel slope of the polarization curve was found to be 30 mV/dec.</p>","PeriodicalId":782,"journal":{"name":"Surface Engineering and Applied Electrochemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140804665","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 : 2024-04-26DOI: 10.3103/s1068375524020157
I. A. Zagidullina, M. F. Galikhanov, A. A. Guzhova, I. I. Muratov, R. M. Garipov, A. A. Efremova
Abstract
This paper describes the study of corona electrets made of a polyethylene terephthalate (PET) laminate film with an aluminum oxide nanolayer with a protective coating based on acrylic copolymers. Those films showed rather high and stable electret properties. Furthermore, dipole polarization prevailed at the acrylic layer due to the orientation of oxygen-containing groups of atoms and macromolecular segments under the corona discharge, while injected charge carriers were located predominantly in polyethylene terephthalate layer at interfaces of both PET-aluminum oxide and amorphous-crystalline regions of the polymer.
{"title":"Electret Properties of PET/AlOx Films with a Protective Coating Based on Acrylic Copolymers","authors":"I. A. Zagidullina, M. F. Galikhanov, A. A. Guzhova, I. I. Muratov, R. M. Garipov, A. A. Efremova","doi":"10.3103/s1068375524020157","DOIUrl":"https://doi.org/10.3103/s1068375524020157","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper describes the study of corona electrets made of a polyethylene terephthalate (PET) laminate film with an aluminum oxide nanolayer with a protective coating based on acrylic copolymers. Those films showed rather high and stable electret properties. Furthermore, dipole polarization prevailed at the acrylic layer due to the orientation of oxygen-containing groups of atoms and macromolecular segments under the corona discharge, while injected charge carriers were located predominantly in polyethylene terephthalate layer at interfaces of both PET-aluminum oxide and amorphous-crystalline regions of the polymer.</p>","PeriodicalId":782,"journal":{"name":"Surface Engineering and Applied Electrochemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140804700","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 : 2024-04-26DOI: 10.3103/s106837552402008x
V. V. Parshutin, A. M. Paramonov, A. V. Koval’
Abstract
The comparative corrosion resistance and electrochemical behavior in acidic, alkaline, and neutral media of both pure metals and the Ni–Re alloys doped with zirconium, hafnium, tungsten, and palladium were investigated. A positive effect of zirconium on the corrosion resistance of the Ni–Re alloy in all studied media was demonstrated. It is shown that the Ni–Re alloy doped with hafnium also improves corrosion resistance and compensates its reduction at introduction to a tungsten alloy. It is shown that the Ni–Re alloy doped with zirconium together with palladium has the maximum corrosion resistance.
{"title":"Corrosion and Electrochemical Properties of Alloys of Ni–Re Systems Alloyed with Zirconium, Hafnium, Tungsten, and Palladium","authors":"V. V. Parshutin, A. M. Paramonov, A. V. Koval’","doi":"10.3103/s106837552402008x","DOIUrl":"https://doi.org/10.3103/s106837552402008x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The comparative corrosion resistance and electrochemical behavior in acidic, alkaline, and neutral media of both pure metals and the Ni–Re alloys doped with zirconium, hafnium, tungsten, and palladium were investigated. A positive effect of zirconium on the corrosion resistance of the Ni–Re alloy in all studied media was demonstrated. It is shown that the Ni–Re alloy doped with hafnium also improves corrosion resistance and compensates its reduction at introduction to a tungsten alloy. It is shown that the Ni–Re alloy doped with zirconium together with palladium has the maximum corrosion resistance.</p>","PeriodicalId":782,"journal":{"name":"Surface Engineering and Applied Electrochemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140804811","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}
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