The Experts below are selected from a list of 18 Experts worldwide ranked by ideXlab platform
Victoria J. Gelling - One of the best experts on this subject based on the ideXlab platform.
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Electrochemical investigations of polypyrrole aluminum flake coupling
Electrochimica Acta, 2010Co-Authors: Maocheng Yan, Christopher A. Vetter, Victoria J. GellingAbstract:Abstract Polypyrrole (PPy) Al flake composite (PAFC) was synthesized by chemical oxidation of pyrrole in the presence of Al flake and was used to formulate a corrosion inhibiting Primer. The anticorrosion performance of the PAFC coating for AA 2024-T3 was evaluated by accelerated salt spray, scanning vibrating electrode technique (SVET), galvanic coupling measurement and electrochemical impedance spectroscopy (EIS). The PAFC Primer showed an enhanced anticorrosion ability for AA 2024-T3 compared to the Al flake Primer and provided cathodic protection for AA 2024-T3 as evidenced by galvanic coupling measurement. A possible corrosion protection mechanism provided by the PAFC and the role of PPy in the formulation were discussed.
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Electrochemically characterizing the ac–dc–ac accelerated test method using embedded electrodes
Corrosion Science, 2009Co-Authors: Gordon P. Bierwagen, Kerry N. Allahar, Victoria J. GellingAbstract:Abstract Embedded sensors were used as an in situ corrosion-sensing device for aircraft and vehicular structures protected by organic coatings. Results are presented where changes associated with standard air force aircraft and army vehicle coatings were monitored by embedded sensors. These coatings consisted of a polyurethane topcoat and an epoxy Primer, however are formulated to provide different characteristics. The ac–dc–ac testing method was used to accelerate the degradation of these coatings while being immersed in a NaCl medium. Electrochemical impedance spectroscopy and electrochemical noise measurement experiments were used to monitor the induced changes. A comparison of the results between coatings subjected to the ac–dc–ac exposure and coatings subjected to only constant immersion in the NaCl medium is presented. The results were used to demonstrate the effectiveness of the ac–dc–ac method at accelerating the degradation of an organic coating without observably changing the normal mechanism of degradation. The data highlights the different features of the coating systems and tracks them while the coating is being degraded. The aircraft coating was characterized by a high-resistant topcoat that can mask corrosion/Primer degradation at the Primer/substrate interface whereas the vehicle coating was characterized by a low-resistant topcoat with an effective corrosion inhibiting Primer. Details of the ac–dc–ac degradation were evaluated by using an equivalent circuit to help interpret the electrochemical impedance data.
A. R. Di Sarli - One of the best experts on this subject based on the ideXlab platform.
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Performance of coated steel systems exposed to different media: Part I. Painted galvanized steel
Progress in Organic Coatings, 2004Co-Authors: B. Del Amo, A. R. Di Sarli, L Véleva, C. I. ElsnerAbstract:The performance of different pre-treated galvanized steel/Primer/topcoat paint systems applied on hot-dip galvanized steel sheets has been studied. Each panel was pre-treated with 5% Fe(NO3)3 + 15% H3PO3 solution. After this step, the panels were coated either with acrylic (AC), alkyd (AK), vinyl (VL), epoxy base-solvent (ES) or epoxy-waterborne (EW) based Corrosion-Inhibiting Primer using zinc molybdenum phosphate as anticorrosive pigment, and with commercially available alkyd topcoat paint. Experimental behavior of these panels under standardized salt spray chamber exposure or continuous immersion in 0.5 M NaCl, 0.5 M Na2SO4 or 0.25 M NaCl + 0.25 M Na2SO4 solutions was evaluated through periodical visual inspection (blistering and rusting degrees) and EIS measurements (corrosion evolution). Initial (dry) and final (wet) paint adhesion was also determined. EIS data has been interpreted and discussed in terms of the time dependence of the electrical (paint coating) and electrochemical (steel substrate) parameters associated with interfacial processes describing the metal/paint system deterioration. According to the electrochemical properties, visual inspection and standardized tests results, the painting systems designated as AK, ES, EW, and VL presented the best overall anticorrosive behavior under immersion conditions, but all samples failed when exposed to the salt spray chamber. System AC behaved very well in 0.25 M NaCl+ 0.25 M Na2SO4 but failed in the other media. Adhesion changes outside the tested areas showed that under immersion conditions there was lateral diffusion. Good correlation between standardized and electrochemical tests results was also obtained. © 2004 Elsevier B.V. All rights reserved.
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The influence of surface pretreatment on the anti-corrosive capacity of painted galvanized steel
Corrosion Prevention & Control, 2003Co-Authors: B. P. Jourdan, C. I. Elsner, A. R. Di SarliAbstract:THE PERFORMANCE different pretreatment/Primer/topcoat paint systems applied on hot-dip galvanized steel sheets has been studied. Each panel was pretreated with one of three processes, after which they were coated with either a vinyl- or alkyd-based Corrosion-Inhibiting Primer and commercially-available alkyd topcoat paint. The experimental behaviour of these panels in a standardized salt spray chamber and artificial weather exposure conditions was evaluated through periodical visual inspection and EIS measurements. The dry and wet paint adhesion before and at the end of the tests was also determined. The Els data was interpreted and is discussed in terms of the time dependence of the electrical and electrochemical parameters associated with the interfacial processes describing the metal/paint system deterioration. According to the electrochemical, visual-inspection, and standardized tests results, the vinyl-coated panels had better corrosion resistance than the alkyd-coated ones. The tests also show that the effect of the pretreatment is not as significant for the corrosion resistance as the barrier effect afforded by the anti-corrosive system. However, in the case of the alkyd-coated samples, an excellent synergistic effect between the pretreatment and the anti-corrosive protection was detected, which is attributed to the fact that such surface treatments can both improve the barrier and/or the inhibiting corrosion protection and the steel/ paint adhesion properties, and reduce the osmotic pressure effect, respectively.
C. I. Elsner - One of the best experts on this subject based on the ideXlab platform.
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Performance of coated steel systems exposed to different media: Part I. Painted galvanized steel
Progress in Organic Coatings, 2004Co-Authors: B. Del Amo, A. R. Di Sarli, L Véleva, C. I. ElsnerAbstract:The performance of different pre-treated galvanized steel/Primer/topcoat paint systems applied on hot-dip galvanized steel sheets has been studied. Each panel was pre-treated with 5% Fe(NO3)3 + 15% H3PO3 solution. After this step, the panels were coated either with acrylic (AC), alkyd (AK), vinyl (VL), epoxy base-solvent (ES) or epoxy-waterborne (EW) based Corrosion-Inhibiting Primer using zinc molybdenum phosphate as anticorrosive pigment, and with commercially available alkyd topcoat paint. Experimental behavior of these panels under standardized salt spray chamber exposure or continuous immersion in 0.5 M NaCl, 0.5 M Na2SO4 or 0.25 M NaCl + 0.25 M Na2SO4 solutions was evaluated through periodical visual inspection (blistering and rusting degrees) and EIS measurements (corrosion evolution). Initial (dry) and final (wet) paint adhesion was also determined. EIS data has been interpreted and discussed in terms of the time dependence of the electrical (paint coating) and electrochemical (steel substrate) parameters associated with interfacial processes describing the metal/paint system deterioration. According to the electrochemical properties, visual inspection and standardized tests results, the painting systems designated as AK, ES, EW, and VL presented the best overall anticorrosive behavior under immersion conditions, but all samples failed when exposed to the salt spray chamber. System AC behaved very well in 0.25 M NaCl+ 0.25 M Na2SO4 but failed in the other media. Adhesion changes outside the tested areas showed that under immersion conditions there was lateral diffusion. Good correlation between standardized and electrochemical tests results was also obtained. © 2004 Elsevier B.V. All rights reserved.
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The influence of surface pretreatment on the anti-corrosive capacity of painted galvanized steel
Corrosion Prevention & Control, 2003Co-Authors: B. P. Jourdan, C. I. Elsner, A. R. Di SarliAbstract:THE PERFORMANCE different pretreatment/Primer/topcoat paint systems applied on hot-dip galvanized steel sheets has been studied. Each panel was pretreated with one of three processes, after which they were coated with either a vinyl- or alkyd-based Corrosion-Inhibiting Primer and commercially-available alkyd topcoat paint. The experimental behaviour of these panels in a standardized salt spray chamber and artificial weather exposure conditions was evaluated through periodical visual inspection and EIS measurements. The dry and wet paint adhesion before and at the end of the tests was also determined. The Els data was interpreted and is discussed in terms of the time dependence of the electrical and electrochemical parameters associated with the interfacial processes describing the metal/paint system deterioration. According to the electrochemical, visual-inspection, and standardized tests results, the vinyl-coated panels had better corrosion resistance than the alkyd-coated ones. The tests also show that the effect of the pretreatment is not as significant for the corrosion resistance as the barrier effect afforded by the anti-corrosive system. However, in the case of the alkyd-coated samples, an excellent synergistic effect between the pretreatment and the anti-corrosive protection was detected, which is attributed to the fact that such surface treatments can both improve the barrier and/or the inhibiting corrosion protection and the steel/ paint adhesion properties, and reduce the osmotic pressure effect, respectively.
Gordon P. Bierwagen - One of the best experts on this subject based on the ideXlab platform.
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Electrochemically characterizing the ac–dc–ac accelerated test method using embedded electrodes
Corrosion Science, 2009Co-Authors: Gordon P. Bierwagen, Kerry N. Allahar, Victoria J. GellingAbstract:Abstract Embedded sensors were used as an in situ corrosion-sensing device for aircraft and vehicular structures protected by organic coatings. Results are presented where changes associated with standard air force aircraft and army vehicle coatings were monitored by embedded sensors. These coatings consisted of a polyurethane topcoat and an epoxy Primer, however are formulated to provide different characteristics. The ac–dc–ac testing method was used to accelerate the degradation of these coatings while being immersed in a NaCl medium. Electrochemical impedance spectroscopy and electrochemical noise measurement experiments were used to monitor the induced changes. A comparison of the results between coatings subjected to the ac–dc–ac exposure and coatings subjected to only constant immersion in the NaCl medium is presented. The results were used to demonstrate the effectiveness of the ac–dc–ac method at accelerating the degradation of an organic coating without observably changing the normal mechanism of degradation. The data highlights the different features of the coating systems and tracks them while the coating is being degraded. The aircraft coating was characterized by a high-resistant topcoat that can mask corrosion/Primer degradation at the Primer/substrate interface whereas the vehicle coating was characterized by a low-resistant topcoat with an effective corrosion inhibiting Primer. Details of the ac–dc–ac degradation were evaluated by using an equivalent circuit to help interpret the electrochemical impedance data.
Kerry N. Allahar - One of the best experts on this subject based on the ideXlab platform.
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Electrochemically characterizing the ac–dc–ac accelerated test method using embedded electrodes
Corrosion Science, 2009Co-Authors: Gordon P. Bierwagen, Kerry N. Allahar, Victoria J. GellingAbstract:Abstract Embedded sensors were used as an in situ corrosion-sensing device for aircraft and vehicular structures protected by organic coatings. Results are presented where changes associated with standard air force aircraft and army vehicle coatings were monitored by embedded sensors. These coatings consisted of a polyurethane topcoat and an epoxy Primer, however are formulated to provide different characteristics. The ac–dc–ac testing method was used to accelerate the degradation of these coatings while being immersed in a NaCl medium. Electrochemical impedance spectroscopy and electrochemical noise measurement experiments were used to monitor the induced changes. A comparison of the results between coatings subjected to the ac–dc–ac exposure and coatings subjected to only constant immersion in the NaCl medium is presented. The results were used to demonstrate the effectiveness of the ac–dc–ac method at accelerating the degradation of an organic coating without observably changing the normal mechanism of degradation. The data highlights the different features of the coating systems and tracks them while the coating is being degraded. The aircraft coating was characterized by a high-resistant topcoat that can mask corrosion/Primer degradation at the Primer/substrate interface whereas the vehicle coating was characterized by a low-resistant topcoat with an effective corrosion inhibiting Primer. Details of the ac–dc–ac degradation were evaluated by using an equivalent circuit to help interpret the electrochemical impedance data.
