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H. S. Mohran - One of the best experts on this subject based on the ideXlab platform.
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Effect of Indium Alloying with Lead on the Mechanical Properties and Corrosion Resistance of Lead-Indium Alloys in Sulfuric Acid Solution
Metallurgical and Materials Transactions A, 2015Co-Authors: Abdel-rahman El-sayed, H. S. Mohran, E.m.m. Ibrahim, Mohamed Ismael, Hoda Abdel Shafy ShilkamyAbstract:Effect of Indium alloying in various concentrations with lead on both microhardness and crystallite structure of lead-Indium alloy was investigated. The corrosion behavior of lead-Indium Alloys in 4 M H2SO4 acid solution was investigated by Tafel plot and electrochemical impedance spectroscopy (EIS) methods. The results of both Tafel plot extrapolation and EIS measurements exhibited the same trend. Generally, the corrosion resistance of the alloy is more significant compared with that observed for pure lead. This study shows that the addition of 0.5 pct In to Pb decreases the corrosion. However, with a further increase of alloying In, the corrosion rate of alloy starts to increase up to 5 pct In compared with that of Pb-0.5 pct In alloy. Then the corrosion rate decreases gradually with the increase in the percentage of In up to 15 pct. The values of activation energy (Ea) supported this trend of the corrosion rate which is obtained for Pb and Pb-In Alloys. X-ray diffraction data exhibited broadness of peaks, which is due to lattice distortion or grain refinement. Clearly the peaks shift to higher angles for Pb-15 pct In alloy which can be attributed to changes in lattice structure of Pb. Scanning electron microscope images confirmed that the microstructure is changed with Indium alloying content. The solute content tends to refine the microstructure array.
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Effect of some nitrogen-heterocyclic compounds on corrosion of tin, Indium, and their Alloys in HClO4
Monatshefte für Chemie - Chemical Monthly, 2012Co-Authors: Abdel-rahman El-sayed, H. S. Mohran, Hany M. Abd El-lateefAbstract:The effect of adenine, adenosine, and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPTZ) on the electrochemical and corrosion behavior of tin, Indium, and tin-Indium Alloys in 0.5 M HClO4 solution at different temperatures was studied. The inhibition efficiency increases with an increase in the concentration of adenine and adenosine in the case of tin and Indium. However, the effect of two mentioned compounds on the corrosion rate of the studied Alloys gives an opposite effect. In the presence of TPTZ, the inhibition efficiency increases as the concentration of the inhibitor is increased in the case of tin. In the case of both Indium and its investigated Alloys, the maximum inhibition efficiency is obtained at the lowest concentration of TPTZ (10−6 M). The adsorption of the studied compounds is found to obey the Frumkin adsorption isotherm. The standard enthalpy $$ \Updelta H_{\rm ads}^{^\circ } , $$ entropy $$ \Updelta S_{\rm ads}^{^\circ } , $$ and free energy changes of adsorption $$ \Updelta G_{\rm ads}^{^\circ } $$ are calculated and discussed.Graphical abstract
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Effect of some nitrogen-heterocyclic compounds on corrosion of tin, Indium, and their Alloys in HClO_4
Monatshefte für Chemie - Chemical Monthly, 2012Co-Authors: Abdel-rahman El-sayed, H. S. Mohran, Hany M. Abd El-lateefAbstract:The effect of adenine, adenosine, and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPTZ) on the electrochemical and corrosion behavior of tin, Indium, and tin-Indium Alloys in 0.5 M HClO_4 solution at different temperatures was studied. The inhibition efficiency increases with an increase in the concentration of adenine and adenosine in the case of tin and Indium. However, the effect of two mentioned compounds on the corrosion rate of the studied Alloys gives an opposite effect. In the presence of TPTZ, the inhibition efficiency increases as the concentration of the inhibitor is increased in the case of tin. In the case of both Indium and its investigated Alloys, the maximum inhibition efficiency is obtained at the lowest concentration of TPTZ (10^−6 M). The adsorption of the studied compounds is found to obey the Frumkin adsorption isotherm. The standard enthalpy $$ \Updelta H_{\rm ads}^{^\circ } , $$ entropy $$ \Updelta S_{\rm ads}^{^\circ } , $$ and free energy changes of adsorption $$ \Updelta G_{\rm ads}^{^\circ } $$ are calculated and discussed. Graphical abstract
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the inhibition effect of 2 4 6 tris 2 pyridyl 1 3 5 triazine on corrosion of tin Indium and tin Indium Alloys in hydrochloric acid solution
Corrosion Science, 2010Co-Authors: Abdelrahman Elsayed, H. S. Mohran, Hany Abd M EllateefAbstract:Abstract The influence of 2,4,6-tris (2-pyridyl)-1,3,5-triazine (TPTZ) on the corrosion of tin, Indium and tin–Indium Alloys in 0.5 M HCl solution at different temperatures was studied. Potentiodynamic cathodic polarization and extrapolation of cathodic and anodic Tafel lines techniques were used to obtained experimental data. In the case of tin, the percent inhibition efficiency (IE%) increases as both concentration of TPTZ and temperature are increased. The value of activation energy ( E a ) is smaller in the presence of TPTZ than that in uninhibited solution, and decreases with increasing the concentration. However, the effect of TPTZ on Indium and the investigated Alloys exhibited similar behavior; so, the maximum inhibition efficiency is observed at lowest concentration (10 −6 M) of TPTZ. Then, the value of inhibition efficiency starts to decrease gradually with increasing TPTZ concentration than that of 10 −6 M. But at higher concentration (10 −3 M) the corrosion current density ( I corr ) is still lower than that in uninhibited solution. SEM photographs support that the higher inhibition efficiency is observed at 10 −6 M of TPTZ. The plots of ln K versus 1/ T in the presence of the TPTZ in the case of tin, the inhibitor showed linear behavior. The standard enthalpy, Δ H° ads. , entropy, Δ S° ads. and free energy changes of adsorption Δ G° ads. were evaluated using Frumkin adsorption isotherm.
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The inhibition effect of 2,4,6-tris (2-pyridyl)-1,3,5-triazine on corrosion of tin, Indium and tin–Indium Alloys in hydrochloric acid solution
Corrosion Science, 2010Co-Authors: Abdel-rahman El-sayed, H. S. Mohran, Hany M. Abd El-lateefAbstract:Abstract The influence of 2,4,6-tris (2-pyridyl)-1,3,5-triazine (TPTZ) on the corrosion of tin, Indium and tin–Indium Alloys in 0.5 M HCl solution at different temperatures was studied. Potentiodynamic cathodic polarization and extrapolation of cathodic and anodic Tafel lines techniques were used to obtained experimental data. In the case of tin, the percent inhibition efficiency (IE%) increases as both concentration of TPTZ and temperature are increased. The value of activation energy ( E a ) is smaller in the presence of TPTZ than that in uninhibited solution, and decreases with increasing the concentration. However, the effect of TPTZ on Indium and the investigated Alloys exhibited similar behavior; so, the maximum inhibition efficiency is observed at lowest concentration (10 −6 M) of TPTZ. Then, the value of inhibition efficiency starts to decrease gradually with increasing TPTZ concentration than that of 10 −6 M. But at higher concentration (10 −3 M) the corrosion current density ( I corr ) is still lower than that in uninhibited solution. SEM photographs support that the higher inhibition efficiency is observed at 10 −6 M of TPTZ. The plots of ln K versus 1/ T in the presence of the TPTZ in the case of tin, the inhibitor showed linear behavior. The standard enthalpy, Δ H° ads. , entropy, Δ S° ads. and free energy changes of adsorption Δ G° ads. were evaluated using Frumkin adsorption isotherm.
Hany Abd M Ellateef - One of the best experts on this subject based on the ideXlab platform.
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the inhibition effect of 2 4 6 tris 2 pyridyl 1 3 5 triazine on corrosion of tin Indium and tin Indium Alloys in hydrochloric acid solution
Corrosion Science, 2010Co-Authors: Abdelrahman Elsayed, H. S. Mohran, Hany Abd M EllateefAbstract:Abstract The influence of 2,4,6-tris (2-pyridyl)-1,3,5-triazine (TPTZ) on the corrosion of tin, Indium and tin–Indium Alloys in 0.5 M HCl solution at different temperatures was studied. Potentiodynamic cathodic polarization and extrapolation of cathodic and anodic Tafel lines techniques were used to obtained experimental data. In the case of tin, the percent inhibition efficiency (IE%) increases as both concentration of TPTZ and temperature are increased. The value of activation energy ( E a ) is smaller in the presence of TPTZ than that in uninhibited solution, and decreases with increasing the concentration. However, the effect of TPTZ on Indium and the investigated Alloys exhibited similar behavior; so, the maximum inhibition efficiency is observed at lowest concentration (10 −6 M) of TPTZ. Then, the value of inhibition efficiency starts to decrease gradually with increasing TPTZ concentration than that of 10 −6 M. But at higher concentration (10 −3 M) the corrosion current density ( I corr ) is still lower than that in uninhibited solution. SEM photographs support that the higher inhibition efficiency is observed at 10 −6 M of TPTZ. The plots of ln K versus 1/ T in the presence of the TPTZ in the case of tin, the inhibitor showed linear behavior. The standard enthalpy, Δ H° ads. , entropy, Δ S° ads. and free energy changes of adsorption Δ G° ads. were evaluated using Frumkin adsorption isotherm.
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corrosion inhibition of tin Indium and tin Indium Alloys by adenine or adenosine in hydrochloric acid solution
Corrosion Science, 2010Co-Authors: Abdelrahman Elsayed, Ali M. Shaker, Hany Abd M EllateefAbstract:Abstract The influence of the concentration of adenine (AD), adenosine (ADS) on the electrochemical corrosion behavior of tin, Indium and tin–Indium Alloys in 0.5 M HCl solution at different temperatures was studied. The investigation involved potentiodynamic cathodic polarization and extrapolation of cathodic and anodic Tafel lines techniques. The inhibition efficiency (IE%) increases with an increase in the concentration of adenine or adenosine of all investigated electrodes. The inhibition process was attributed to the formation of adsorbed film on the surfaces of the electrodes that protects the surface against corrosive agent. The data exhibited that the inhibition efficiency slightly decreases with increasing temperature. Frumkin adsorption isotherm fits well the experimental data. The plots of ln K vs. 1/ T in the presence of the two studied inhibitors showed linear behavior. The standard enthalpy, Δ H ads ∘ , entropy, Δ S ads ∘ and free energy changes of adsorption Δ G ads ∘ were evaluated; the calculated values of Δ H ads ∘ and Δ G ads ∘ were negative while those for Δ S ads ∘ were positive. Mainly, all the above results are suggestive of physisorption of the inhibitor molecules on the surfaces of the investigated electrodes.
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potentiodynamic studies on anodic dissolution and passivation of tin Indium and tin Indium Alloys in some fruit acids solutions
Corrosion Science, 2009Co-Authors: Abdelrahman Elsayed, H. S. Mohran, Hany Abd M EllateefAbstract:Abstract The anodic dissolution and passivation of tin, Indium and tin–Indium Alloys were studied in 0.5 M solutions of both malic and citric acids, using potentiodynamic technique and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The E / I curves showed that the anodic behavior of all investigated electrodes exhibits active/passive transition. The active region of tin involves two anodic peaks (I and II) prior to the passive region in both the investigated acids, while Indium exhibits two peaks (I and II) in malic and one peak in citric acid. These two peaks (I and II) correspond to the formation of InOOH and In(OH) 3 /In 2 O 3 system, respectively, but that observed peak in citric acid is to InOOH. The active region for tin–Indium Alloys ( I , II and III ) in citric acid showed one peak (I) and shoulders (II). This shoulder predominates with increasing temperature due to little In 2 O 3 formation and its dissolution at higher temperatures. The disappearance of this shoulder for the Alloys ( IV and V ) with high Indium percent may be due to the formation of large amounts of In 2 O 3 with tin oxides on the surface.
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anodic behavior of tin Indium and tin Indium Alloys in oxalic acid solution
Journal of Solid State Electrochemistry, 2009Co-Authors: H. S. Mohran, Abdelrahman Elsayed, Hany Abd M EllateefAbstract:The anodic behavior of tin, Indium, and tin–Indium Alloys was studied in oxalic acid solution using potentiodynamic technique and characterized by X-ray diffraction and scanning electron microscopy. The E/I curves showed that the anodic behavior of all investigated electrodes exhibits active/passive transition. In the case of tin, the active dissolution region involves two anodic peaks (I and II) prior to permanent passive region. On the other hand, the active dissolution of Indium involves four peaks (I–IV) prior to permanent passive region. The first (I) can be associated with the active dissolution of Indium to InOOH, the second peak (II) to the formation of In(OH)3, the third peak (III) to partially dehydration of In(OH)3, and the peak (IV) to complete dehydration of In(OH)3 to In2O3. When the surface is entirely covered with In2O3 film, the anodic current falls to a small value (I pass) indicating the onset of passivation. The active dissolution potential region of the first three tin–Indium Alloys involves a net anodic contribution peak, and this is followed by a passive region. It is expected that the investigated peak is related to the formation of In2O3 and SnO (mixed oxides). When the formation of oxides (the oxides of In and Sn) exceeds its dissolution rate, the current drops, indicating the onset of passivation precipitation of In2O3/SnO and SnO2 on the surface which blocks the dissolution of active sites. The Alloys IV and V showed small second peak at about −620 mV which may be related to oxidation of In to In2O3 due to high In content in the two examined Alloys. The active dissolution and passive current are increase with increasing temperature for all investigated metals and their Alloys.
Hany M. Abd El-lateef - One of the best experts on this subject based on the ideXlab platform.
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Corrosion inhibition of tin, Indium and tin–Indium Alloys by adenine or adenosine in hydrochloric acid solution
Corrosion Science, 2010Co-Authors: Abdel-rahman El-sayed, Ali M. Shaker, Hany M. Abd El-lateefAbstract:Abstract The influence of the concentration of adenine (AD), adenosine (ADS) on the electrochemical corrosion behavior of tin, Indium and tin–Indium Alloys in 0.5 M HCl solution at different temperatures was studied. The investigation involved potentiodynamic cathodic polarization and extrapolation of cathodic and anodic Tafel lines techniques. The inhibition efficiency (IE%) increases with an increase in the concentration of adenine or adenosine of all investigated electrodes. The inhibition process was attributed to the formation of adsorbed film on the surfaces of the electrodes that protects the surface against corrosive agent. The data exhibited that the inhibition efficiency slightly decreases with increasing temperature. Frumkin adsorption isotherm fits well the experimental data. The plots of ln K vs. 1/ T in the presence of the two studied inhibitors showed linear behavior. The standard enthalpy, Δ H ads ∘ , entropy, Δ S ads ∘ and free energy changes of adsorption Δ G ads ∘ were evaluated; the calculated values of Δ H ads ∘ and Δ G ads ∘ were negative while those for Δ S ads ∘ were positive. Mainly, all the above results are suggestive of physisorption of the inhibitor molecules on the surfaces of the investigated electrodes.
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The inhibition effect of 2,4,6-tris (2-pyridyl)-1,3,5-triazine on corrosion of tin, Indium and tin–Indium Alloys in hydrochloric acid solution
Corrosion Science, 2010Co-Authors: Abdel-rahman El-sayed, H. S. Mohran, Hany M. Abd El-lateefAbstract:Abstract The influence of 2,4,6-tris (2-pyridyl)-1,3,5-triazine (TPTZ) on the corrosion of tin, Indium and tin–Indium Alloys in 0.5 M HCl solution at different temperatures was studied. Potentiodynamic cathodic polarization and extrapolation of cathodic and anodic Tafel lines techniques were used to obtained experimental data. In the case of tin, the percent inhibition efficiency (IE%) increases as both concentration of TPTZ and temperature are increased. The value of activation energy ( E a ) is smaller in the presence of TPTZ than that in uninhibited solution, and decreases with increasing the concentration. However, the effect of TPTZ on Indium and the investigated Alloys exhibited similar behavior; so, the maximum inhibition efficiency is observed at lowest concentration (10 −6 M) of TPTZ. Then, the value of inhibition efficiency starts to decrease gradually with increasing TPTZ concentration than that of 10 −6 M. But at higher concentration (10 −3 M) the corrosion current density ( I corr ) is still lower than that in uninhibited solution. SEM photographs support that the higher inhibition efficiency is observed at 10 −6 M of TPTZ. The plots of ln K versus 1/ T in the presence of the TPTZ in the case of tin, the inhibitor showed linear behavior. The standard enthalpy, Δ H° ads. , entropy, Δ S° ads. and free energy changes of adsorption Δ G° ads. were evaluated using Frumkin adsorption isotherm.
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Potentiodynamic studies on anodic dissolution and passivation of tin, Indium and tin–Indium Alloys in some fruit acids solutions
Corrosion Science, 2009Co-Authors: Abdel-rahman El-sayed, H. S. Mohran, Hany M. Abd El-lateefAbstract:Abstract The anodic dissolution and passivation of tin, Indium and tin–Indium Alloys were studied in 0.5 M solutions of both malic and citric acids, using potentiodynamic technique and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The E / I curves showed that the anodic behavior of all investigated electrodes exhibits active/passive transition. The active region of tin involves two anodic peaks (I and II) prior to the passive region in both the investigated acids, while Indium exhibits two peaks (I and II) in malic and one peak in citric acid. These two peaks (I and II) correspond to the formation of InOOH and In(OH) 3 /In 2 O 3 system, respectively, but that observed peak in citric acid is to InOOH. The active region for tin–Indium Alloys ( I , II and III ) in citric acid showed one peak (I) and shoulders (II). This shoulder predominates with increasing temperature due to little In 2 O 3 formation and its dissolution at higher temperatures. The disappearance of this shoulder for the Alloys ( IV and V ) with high Indium percent may be due to the formation of large amounts of In 2 O 3 with tin oxides on the surface.
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Anodic behavior of tin, Indium, and tin–Indium Alloys in oxalic acid solution
Journal of Solid State Electrochemistry, 2008Co-Authors: H. S. Mohran, Abdel-rahman El-sayed, Hany M. Abd El-lateefAbstract:The anodic behavior of tin, Indium, and tin–Indium Alloys was studied in oxalic acid solution using potentiodynamic technique and characterized by X-ray diffraction and scanning electron microscopy. The E/I curves showed that the anodic behavior of all investigated electrodes exhibits active/passive transition. In the case of tin, the active dissolution region involves two anodic peaks (I and II) prior to permanent passive region. On the other hand, the active dissolution of Indium involves four peaks (I–IV) prior to permanent passive region. The first (I) can be associated with the active dissolution of Indium to InOOH, the second peak (II) to the formation of In(OH)3, the third peak (III) to partially dehydration of In(OH)3, and the peak (IV) to complete dehydration of In(OH)3 to In2O3. When the surface is entirely covered with In2O3 film, the anodic current falls to a small value (I pass) indicating the onset of passivation. The active dissolution potential region of the first three tin–Indium Alloys involves a net anodic contribution peak, and this is followed by a passive region. It is expected that the investigated peak is related to the formation of In2O3 and SnO (mixed oxides). When the formation of oxides (the oxides of In and Sn) exceeds its dissolution rate, the current drops, indicating the onset of passivation precipitation of In2O3/SnO and SnO2 on the surface which blocks the dissolution of active sites. The Alloys IV and V showed small second peak at about −620 mV which may be related to oxidation of In to In2O3 due to high In content in the two examined Alloys. The active dissolution and passive current are increase with increasing temperature for all investigated metals and their Alloys.
Abdel-rahman El-sayed - One of the best experts on this subject based on the ideXlab platform.
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Effect of Indium Alloying with Lead on the Mechanical Properties and Corrosion Resistance of Lead-Indium Alloys in Sulfuric Acid Solution
Metallurgical and Materials Transactions A, 2015Co-Authors: Abdel-rahman El-sayed, H. S. Mohran, E.m.m. Ibrahim, Mohamed Ismael, Hoda Abdel Shafy ShilkamyAbstract:Effect of Indium alloying in various concentrations with lead on both microhardness and crystallite structure of lead-Indium alloy was investigated. The corrosion behavior of lead-Indium Alloys in 4 M H2SO4 acid solution was investigated by Tafel plot and electrochemical impedance spectroscopy (EIS) methods. The results of both Tafel plot extrapolation and EIS measurements exhibited the same trend. Generally, the corrosion resistance of the alloy is more significant compared with that observed for pure lead. This study shows that the addition of 0.5 pct In to Pb decreases the corrosion. However, with a further increase of alloying In, the corrosion rate of alloy starts to increase up to 5 pct In compared with that of Pb-0.5 pct In alloy. Then the corrosion rate decreases gradually with the increase in the percentage of In up to 15 pct. The values of activation energy (Ea) supported this trend of the corrosion rate which is obtained for Pb and Pb-In Alloys. X-ray diffraction data exhibited broadness of peaks, which is due to lattice distortion or grain refinement. Clearly the peaks shift to higher angles for Pb-15 pct In alloy which can be attributed to changes in lattice structure of Pb. Scanning electron microscope images confirmed that the microstructure is changed with Indium alloying content. The solute content tends to refine the microstructure array.
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Effect of some nitrogen-heterocyclic compounds on corrosion of tin, Indium, and their Alloys in HClO4
Monatshefte für Chemie - Chemical Monthly, 2012Co-Authors: Abdel-rahman El-sayed, H. S. Mohran, Hany M. Abd El-lateefAbstract:The effect of adenine, adenosine, and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPTZ) on the electrochemical and corrosion behavior of tin, Indium, and tin-Indium Alloys in 0.5 M HClO4 solution at different temperatures was studied. The inhibition efficiency increases with an increase in the concentration of adenine and adenosine in the case of tin and Indium. However, the effect of two mentioned compounds on the corrosion rate of the studied Alloys gives an opposite effect. In the presence of TPTZ, the inhibition efficiency increases as the concentration of the inhibitor is increased in the case of tin. In the case of both Indium and its investigated Alloys, the maximum inhibition efficiency is obtained at the lowest concentration of TPTZ (10−6 M). The adsorption of the studied compounds is found to obey the Frumkin adsorption isotherm. The standard enthalpy $$ \Updelta H_{\rm ads}^{^\circ } , $$ entropy $$ \Updelta S_{\rm ads}^{^\circ } , $$ and free energy changes of adsorption $$ \Updelta G_{\rm ads}^{^\circ } $$ are calculated and discussed.Graphical abstract
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Effect of some nitrogen-heterocyclic compounds on corrosion of tin, Indium, and their Alloys in HClO_4
Monatshefte für Chemie - Chemical Monthly, 2012Co-Authors: Abdel-rahman El-sayed, H. S. Mohran, Hany M. Abd El-lateefAbstract:The effect of adenine, adenosine, and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPTZ) on the electrochemical and corrosion behavior of tin, Indium, and tin-Indium Alloys in 0.5 M HClO_4 solution at different temperatures was studied. The inhibition efficiency increases with an increase in the concentration of adenine and adenosine in the case of tin and Indium. However, the effect of two mentioned compounds on the corrosion rate of the studied Alloys gives an opposite effect. In the presence of TPTZ, the inhibition efficiency increases as the concentration of the inhibitor is increased in the case of tin. In the case of both Indium and its investigated Alloys, the maximum inhibition efficiency is obtained at the lowest concentration of TPTZ (10^−6 M). The adsorption of the studied compounds is found to obey the Frumkin adsorption isotherm. The standard enthalpy $$ \Updelta H_{\rm ads}^{^\circ } , $$ entropy $$ \Updelta S_{\rm ads}^{^\circ } , $$ and free energy changes of adsorption $$ \Updelta G_{\rm ads}^{^\circ } $$ are calculated and discussed. Graphical abstract
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Corrosion inhibition of tin, Indium and tin–Indium Alloys by adenine or adenosine in hydrochloric acid solution
Corrosion Science, 2010Co-Authors: Abdel-rahman El-sayed, Ali M. Shaker, Hany M. Abd El-lateefAbstract:Abstract The influence of the concentration of adenine (AD), adenosine (ADS) on the electrochemical corrosion behavior of tin, Indium and tin–Indium Alloys in 0.5 M HCl solution at different temperatures was studied. The investigation involved potentiodynamic cathodic polarization and extrapolation of cathodic and anodic Tafel lines techniques. The inhibition efficiency (IE%) increases with an increase in the concentration of adenine or adenosine of all investigated electrodes. The inhibition process was attributed to the formation of adsorbed film on the surfaces of the electrodes that protects the surface against corrosive agent. The data exhibited that the inhibition efficiency slightly decreases with increasing temperature. Frumkin adsorption isotherm fits well the experimental data. The plots of ln K vs. 1/ T in the presence of the two studied inhibitors showed linear behavior. The standard enthalpy, Δ H ads ∘ , entropy, Δ S ads ∘ and free energy changes of adsorption Δ G ads ∘ were evaluated; the calculated values of Δ H ads ∘ and Δ G ads ∘ were negative while those for Δ S ads ∘ were positive. Mainly, all the above results are suggestive of physisorption of the inhibitor molecules on the surfaces of the investigated electrodes.
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The inhibition effect of 2,4,6-tris (2-pyridyl)-1,3,5-triazine on corrosion of tin, Indium and tin–Indium Alloys in hydrochloric acid solution
Corrosion Science, 2010Co-Authors: Abdel-rahman El-sayed, H. S. Mohran, Hany M. Abd El-lateefAbstract:Abstract The influence of 2,4,6-tris (2-pyridyl)-1,3,5-triazine (TPTZ) on the corrosion of tin, Indium and tin–Indium Alloys in 0.5 M HCl solution at different temperatures was studied. Potentiodynamic cathodic polarization and extrapolation of cathodic and anodic Tafel lines techniques were used to obtained experimental data. In the case of tin, the percent inhibition efficiency (IE%) increases as both concentration of TPTZ and temperature are increased. The value of activation energy ( E a ) is smaller in the presence of TPTZ than that in uninhibited solution, and decreases with increasing the concentration. However, the effect of TPTZ on Indium and the investigated Alloys exhibited similar behavior; so, the maximum inhibition efficiency is observed at lowest concentration (10 −6 M) of TPTZ. Then, the value of inhibition efficiency starts to decrease gradually with increasing TPTZ concentration than that of 10 −6 M. But at higher concentration (10 −3 M) the corrosion current density ( I corr ) is still lower than that in uninhibited solution. SEM photographs support that the higher inhibition efficiency is observed at 10 −6 M of TPTZ. The plots of ln K versus 1/ T in the presence of the TPTZ in the case of tin, the inhibitor showed linear behavior. The standard enthalpy, Δ H° ads. , entropy, Δ S° ads. and free energy changes of adsorption Δ G° ads. were evaluated using Frumkin adsorption isotherm.
Rebecca K. Kramer - One of the best experts on this subject based on the ideXlab platform.
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Integrating Systems for Liquid/Substrate Characterization and Functional Printing
2015Co-Authors: J. William Boley, Rebecca K. KramerAbstract:Gallium-Indium Alloys are recently applied in fabricating soft devices, such as stretchable sensors, electric circuits, micro pumps and optics. Its printability demonstrates the possibility for a wide extension of the application. Current fabrication methods are inefficient when printing is most handled manually, and are highly dependent on material properties. There is need for a fast way to characterize material properties, and to functionally print the given shape on the substrate. This paper presents the construction of an efficiently integrated system with optical imaging and functional printing for Gallium-Indium Alloys. The imaging section allows for characterization of material properties to fast and accurately determine printing parameters in printing section. A new algorithm, which extends generalized Hough Transform, is designed to determine the contact angle of sessile drops by fitting the shape based on Bashforth-Adams equation. The results are later applied in determination of featured geometry in printing. The algorithm shows relatively low errors in profiling the sessile drop shapes. However, the results are not stable for 5% of test pictures, and thus revisions are still needed. In addition, functional printing is finalized with a direct writing module and a friendly user interface. A series of the state-of-the-art algorithms are adopted in image analysis and controlling. Test printing shows its workability, flexibility and accordance to the previous work. The integrated system presents a solution for both accuracy and efficiency in Gallium-Indium alloy printing.
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direct writing of gallium Indium alloy for stretchable electronics
Advanced Functional Materials, 2014Co-Authors: William J Boley, Edward L White, George T C Chiu, Rebecca K. KramerAbstract:In this paper, a direct writing method for gallium-Indium Alloys is presented. The relationships between nozzle inner diameter, standoff distance, flow rate, and the resulting trace geometry are demonstrated. The interaction between the gallium oxide layer and the substrate is critically important in understanding the printing behavior of the liquid metal. The difference between receding and advancing contact angles demonstrates that the adhesion of the oxide layer to the substrate surface is stronger than the wetting of the surface by the gallium-Indium alloy. This further demonstrates why free-standing structures such as the traces described herein can be realized. In addition to the basic characterization of the direct writing process, a design algorithm that is generalizable to a range of trace geometries is developed. This method is applied to the fabrication of an elastomer-encapsulated strain gauge that displays an approximately linear behavior through 50% strain with a gauge factor of 1.5.
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Direct Writing of Gallium‐Indium Alloy for Stretchable Electronics
Advanced Functional Materials, 2014Co-Authors: J. William Boley, Edward L White, George T C Chiu, Rebecca K. KramerAbstract:In this paper, a direct writing method for gallium-Indium Alloys is presented. The relationships between nozzle inner diameter, standoff distance, flow rate, and the resulting trace geometry are demonstrated. The interaction between the gallium oxide layer and the substrate is critically important in understanding the printing behavior of the liquid metal. The difference between receding and advancing contact angles demonstrates that the adhesion of the oxide layer to the substrate surface is stronger than the wetting of the surface by the gallium-Indium alloy. This further demonstrates why free-standing structures such as the traces described herein can be realized. In addition to the basic characterization of the direct writing process, a design algorithm that is generalizable to a range of trace geometries is developed. This method is applied to the fabrication of an elastomer-encapsulated strain gauge that displays an approximately linear behavior through 50% strain with a gauge factor of 1.5.
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Effect of Microtextured Surface Topography on the Wetting Behavior of Eutectic Gallium–Indium Alloys
Langmuir : the ACS journal of surfaces and colloids, 2014Co-Authors: Rebecca K. Kramer, J. William Boley, Howard A. Stone, James C. Weaver, Robert J. WoodAbstract:Liquid-embedded elastomer electronics have recently attracted much attention as key elements of highly deformable and “soft” electromechanical systems. Many of these fluid–elastomer composites utilize liquid metal Alloys because of their high conductivities and inherent compliance. Understanding how these Alloys interface with surfaces of various composition and texture is critical to the development of parallel processing technology, which is needed to create more complex and low-cost systems. In this work, we explore the wetting behaviors between droplets of gallium–Indium Alloys and thin metal films, with an emphasis on tin and Indium substrates. We find that metallic droplets reactively wet thin metal foils, but the wettability of the foils may be tuned by the surface texture (produced by sputtering). The effects of both composition and texture of the substrate on wetting dynamics are quantified by measuring contact angle and droplet contact diameter as a function of time. Finally, we apply the Cassie...
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effect of microtextured surface topography on the wetting behavior of eutectic gallium Indium Alloys
Langmuir, 2014Co-Authors: Rebecca K. Kramer, Howard A. Stone, James C. Weaver, William J Boley, Robert J. WoodAbstract:Liquid-embedded elastomer electronics have recently attracted much attention as key elements of highly deformable and “soft” electromechanical systems. Many of these fluid–elastomer composites utilize liquid metal Alloys because of their high conductivities and inherent compliance. Understanding how these Alloys interface with surfaces of various composition and texture is critical to the development of parallel processing technology, which is needed to create more complex and low-cost systems. In this work, we explore the wetting behaviors between droplets of gallium–Indium Alloys and thin metal films, with an emphasis on tin and Indium substrates. We find that metallic droplets reactively wet thin metal foils, but the wettability of the foils may be tuned by the surface texture (produced by sputtering). The effects of both composition and texture of the substrate on wetting dynamics are quantified by measuring contact angle and droplet contact diameter as a function of time. Finally, we apply the Cassie...
