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Qafsaoui W.,British Petroleum | Kendig M.W.,Kendig Research Associates LLC | Perrot H.,French National Center for Scientific Research | Perrot H.,University Pierre and Marie Curie | And 2 more authors.
Electrochimica Acta | Year: 2013

In this work, as for the preliminary step to the protection of Al 2xxx alloys, the anticorrosion effect of environmentally friendly 1-pyrrolidine dithiocarbamate (PDTC) on Cu was investigated by combining various electrochemical methods in addition to SEM-EDS analyses and gravimetric measurements. The Cu/PDTC system was used as a model to simulate the inhibition of Cu-rich particles contained in Al 2xxx alloys. The corrosion test solution was 0.5 mol L-1 NaCl in the presence of 10-4, 10 -3, or 10-2 mol L-1 PDTC. The immersion time of the copper electrode was extended generally up to 24 h. By EQCM measurements, a marked protective effect of PDTC was observed for the highest PDTC used, and corroborated by voltammetry and EIS measurements. The cathodic reduction under constant current allowed determining the corrosion products remaining on the copper surface in terms of electrical charge. The protective effect of PDTC was explained by the formation of highly stable compounds on the copper surface, which decreases the rate of both anodic dissolution and oxygen reduction reaction. © 2012 Elsevier Ltd.

Qafsaoui W.,British Petroleum | Kendig M.W.,Kendig Research Associates LLC | Joiret S.,Paris-Sorbonne University | Perrot H.,Paris-Sorbonne University | Takenouti H.,Paris-Sorbonne University
Corrosion Science | Year: 2016

Adsorption of ammonium pyrrolidine dithiocarbamate (PDTC) on copper surface in 0.2 and 30gL-1 NaCl media was investigated by different electrochemical methods and surface analyses. The results from electrochemical measurements showed that PDTC adsorbs rapidly on copper surface and revealed a marked effect of mixed inhibition. Surface analyses confirm the adsorption of PDTC on copper and the formation of a Cu-PDTC complex through the S atoms of PDTC. At high concentrations PDTC prevents oxides and cuprous chloride formation. XPS results showed that PDTC bonds with cuprous species indicating the formation of CuI-PDTC complex. © 2016 Elsevier Ltd.

Qafsaoui W.,British Petroleum | Kendig M.W.,Kendig Research Associates LLC | Perrot H.,CNRS Laboratory Interfaces & Systems Electrochemistry | Takenouti H.,CNRS Laboratory Interfaces & Systems Electrochemistry
Corrosion Science | Year: 2015

1-pyrrolidine dithiocarbamate (PDTC) effect on galvanic coupling resistance of AA 2024-T3 alloy in 0.2gL- 1 NaCl was evaluated by different electrochemical/gravimetric methods and surface analysis. The results obtained from polarization curves and electrochemical quartz crystal microbalance measurements showed that PDTC forms an adsorbed film on the Cu-rich particles, likely through a CuI-PDTC complex. At high concentrations, PDTC significantly decreases the alloy reactivity thereby providing a marked corrosion protection. SEM-EDX analysis showed that PDTC adsorbs preferentially on the Al-Cu-Mg particles. Electrochemical impedance spectroscopy measurements corroborate these results and show furthermore that PDTC addition increases the galvanic coupling resistance. © 2014 Elsevier Ltd.

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