Electrochemical impedance spectroscopy (EIS) is a powerful technique to study not only the fundamental aspects of the coatings, but also evaluate their corrosion performance. EIS provides insights into chemical and physical properties of the coatings. In addition, it is non-destructive and rapid test.
Vapor grown carbon nano-fiber (VGCNF) samples (~200 nm diam, ~30-100 µm length with 21 and 18 m2/g total and external surface areas, respectively) were mixed with a commercial paint sample in various VGCNF loadings. These samples were then used to coat mild steel samples to study the effect of the added VGCNF on the performance of the pure coating.
In this work, EIS measurements have been made on coated samples immersed in 3% NaCl. Both pure paint- and VGCNF/paint-coated mild steel coupons, having different coat thicknesses and different % of VGCNF, were studied. EIS has made it possible to monitor the penetration of the surrounding electrolyte into the organic coating and determine the extent of the coating breakdown.
Impedance and corrosion potential measurements as a function of time were used to rank the effectiveness of the anticorrosive properties in the 3% NaCl solution of the different paint- and VGCNF/paint-samples. The equivalent electrical modeling (equivalent circuits) of these paint- and VGCNF/paint-coated mild steel samples will be presented and used to explain the impedance results.
Back to Nanoscale Materials: Synthesis, Application and Development II (General Session)
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