The Experts below are selected from a list of 12 Experts worldwide ranked by ideXlab platform
J Clavilier - One of the best experts on this subject based on the ideXlab platform.
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electrochemical behaviour of pt 100 in various acidic media part i on a new voltammetric profile of pt 100 in perchloric acid and effects of surface defects
Journal of Electroanalytical Chemistry, 1991Co-Authors: Antonio Rodes, M A Zamakhchari, El K Achi, J ClavilierAbstract:A new voltammetric profile is obtained for Pt(100) electrodes in perchloric acid solutions when the amount of oxygen adsorbed during the Flame Cleaning procedure is reduced to a minimum by cooling the sample in a H2 + Ar atmosphere. A reduction in the amount of hydrogen adsorbed below 0.2 V as well as the positive shift of the onset of electrochemical oxygen adsorption suggest that these cooling conditions give rise to a surface with a very low content of surface defects. On the other hand, the increase in the population of the adsorption states between 0.35 and 0.70 V indicates an increase of the two-dimensional long range order of the (100) surface domains. This is concluded from the effect on these states of repeated cycles of electrochemical oxygen adsorption and desorption, which are known to disrupt the two-dimensional long range order. These conclusions parallel those reached for the same orientation in sulphuric acid. A difference between the two media is a well marked peak for oxygen adsorption at 1.025 V appearing in perchloric acid for the H2 + Ar cooled electrode. An excess of charge measured in perchloric medium between 0.15 and 0.73 V is tentatively assigned to an increase of the density of hydrogen adsorption sites since SHG results indicate that hydrogen is the only species giving rise to the adsorption states in this potential range. According to quantitative data for hydrogen adsorption, the new voltammetric profile can be ascribed provisionally to the Pt(100) (5×20) closely packed surface structure. The effect of electrochemical oxygen adsorption is discussed and electrochemical criteria for the absence of surface defects on the voltammograms obtained for Pt(100) and Pt(111) in perchloric solutions are given.
Antonio Rodes - One of the best experts on this subject based on the ideXlab platform.
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electrochemical behaviour of pt 100 in various acidic media part i on a new voltammetric profile of pt 100 in perchloric acid and effects of surface defects
Journal of Electroanalytical Chemistry, 1991Co-Authors: Antonio Rodes, M A Zamakhchari, El K Achi, J ClavilierAbstract:A new voltammetric profile is obtained for Pt(100) electrodes in perchloric acid solutions when the amount of oxygen adsorbed during the Flame Cleaning procedure is reduced to a minimum by cooling the sample in a H2 + Ar atmosphere. A reduction in the amount of hydrogen adsorbed below 0.2 V as well as the positive shift of the onset of electrochemical oxygen adsorption suggest that these cooling conditions give rise to a surface with a very low content of surface defects. On the other hand, the increase in the population of the adsorption states between 0.35 and 0.70 V indicates an increase of the two-dimensional long range order of the (100) surface domains. This is concluded from the effect on these states of repeated cycles of electrochemical oxygen adsorption and desorption, which are known to disrupt the two-dimensional long range order. These conclusions parallel those reached for the same orientation in sulphuric acid. A difference between the two media is a well marked peak for oxygen adsorption at 1.025 V appearing in perchloric acid for the H2 + Ar cooled electrode. An excess of charge measured in perchloric medium between 0.15 and 0.73 V is tentatively assigned to an increase of the density of hydrogen adsorption sites since SHG results indicate that hydrogen is the only species giving rise to the adsorption states in this potential range. According to quantitative data for hydrogen adsorption, the new voltammetric profile can be ascribed provisionally to the Pt(100) (5×20) closely packed surface structure. The effect of electrochemical oxygen adsorption is discussed and electrochemical criteria for the absence of surface defects on the voltammograms obtained for Pt(100) and Pt(111) in perchloric solutions are given.
M A Zamakhchari - One of the best experts on this subject based on the ideXlab platform.
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electrochemical behaviour of pt 100 in various acidic media part i on a new voltammetric profile of pt 100 in perchloric acid and effects of surface defects
Journal of Electroanalytical Chemistry, 1991Co-Authors: Antonio Rodes, M A Zamakhchari, El K Achi, J ClavilierAbstract:A new voltammetric profile is obtained for Pt(100) electrodes in perchloric acid solutions when the amount of oxygen adsorbed during the Flame Cleaning procedure is reduced to a minimum by cooling the sample in a H2 + Ar atmosphere. A reduction in the amount of hydrogen adsorbed below 0.2 V as well as the positive shift of the onset of electrochemical oxygen adsorption suggest that these cooling conditions give rise to a surface with a very low content of surface defects. On the other hand, the increase in the population of the adsorption states between 0.35 and 0.70 V indicates an increase of the two-dimensional long range order of the (100) surface domains. This is concluded from the effect on these states of repeated cycles of electrochemical oxygen adsorption and desorption, which are known to disrupt the two-dimensional long range order. These conclusions parallel those reached for the same orientation in sulphuric acid. A difference between the two media is a well marked peak for oxygen adsorption at 1.025 V appearing in perchloric acid for the H2 + Ar cooled electrode. An excess of charge measured in perchloric medium between 0.15 and 0.73 V is tentatively assigned to an increase of the density of hydrogen adsorption sites since SHG results indicate that hydrogen is the only species giving rise to the adsorption states in this potential range. According to quantitative data for hydrogen adsorption, the new voltammetric profile can be ascribed provisionally to the Pt(100) (5×20) closely packed surface structure. The effect of electrochemical oxygen adsorption is discussed and electrochemical criteria for the absence of surface defects on the voltammograms obtained for Pt(100) and Pt(111) in perchloric solutions are given.
El K Achi - One of the best experts on this subject based on the ideXlab platform.
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electrochemical behaviour of pt 100 in various acidic media part i on a new voltammetric profile of pt 100 in perchloric acid and effects of surface defects
Journal of Electroanalytical Chemistry, 1991Co-Authors: Antonio Rodes, M A Zamakhchari, El K Achi, J ClavilierAbstract:A new voltammetric profile is obtained for Pt(100) electrodes in perchloric acid solutions when the amount of oxygen adsorbed during the Flame Cleaning procedure is reduced to a minimum by cooling the sample in a H2 + Ar atmosphere. A reduction in the amount of hydrogen adsorbed below 0.2 V as well as the positive shift of the onset of electrochemical oxygen adsorption suggest that these cooling conditions give rise to a surface with a very low content of surface defects. On the other hand, the increase in the population of the adsorption states between 0.35 and 0.70 V indicates an increase of the two-dimensional long range order of the (100) surface domains. This is concluded from the effect on these states of repeated cycles of electrochemical oxygen adsorption and desorption, which are known to disrupt the two-dimensional long range order. These conclusions parallel those reached for the same orientation in sulphuric acid. A difference between the two media is a well marked peak for oxygen adsorption at 1.025 V appearing in perchloric acid for the H2 + Ar cooled electrode. An excess of charge measured in perchloric medium between 0.15 and 0.73 V is tentatively assigned to an increase of the density of hydrogen adsorption sites since SHG results indicate that hydrogen is the only species giving rise to the adsorption states in this potential range. According to quantitative data for hydrogen adsorption, the new voltammetric profile can be ascribed provisionally to the Pt(100) (5×20) closely packed surface structure. The effect of electrochemical oxygen adsorption is discussed and electrochemical criteria for the absence of surface defects on the voltammograms obtained for Pt(100) and Pt(111) in perchloric solutions are given.
C. Shen - One of the best experts on this subject based on the ideXlab platform.
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Effect of Flame Cleaning of ceramic surface on the bond strength of composite to ceramic.
Journal of oral rehabilitation, 2005Co-Authors: C. ShenAbstract:This study tested the hypothesis that Flame Cleaning of ceramic surface would increase the bond strength of composite to ceramic than pressure-vaporized steam Cleaning. Eris and IPS-Empress ceramic blocks were fabricated, polished (control), airborne-particle abraded with 50-microm alumina particle (A), etched with 5% hydrofluoric acid gel for 2 min (E), or treated with a combination of A and E (AE). They were subjected to either steam Cleaning for 20 s or Flame Cleaning over a gas burner for 2 s. Followed by an application of an adhesive resin, a composite was built-up. Twenty micro-tensile test specimens (approximately 0.9 x 0.9 x 16 mm) were obtained from each group and loaded to failure under tensile force using a universal testing machine at a crosshead speed of 0.5 mm min(-1). anova showed statistically significant differences in the mean bond strength by ceramic, surface roughness, and Cleaning method (P steam-cleaned; IPS-Empress > Eris; and AE > E > A for IPS-Empress and AE > E approximately A for Eris (Duncan's multiple analysis; alpha = 0.05). This in vitro study suggests that mechanical bond of composite to ceramic can be improved with Flame Cleaning of ceramic surface.