G. Ebrahimi - Corrosion Department, Research Institute of Petroleum Industry (RIPI), Tehran, Iran
F. Rezaei - Coating Research Center, Research Institute of Petroleum Industry (RIPI), Tehran, Iran
J. Neshati - Corrosion Department, Research Institute of Petroleum Industry (RIPI), Tehran, Iran

In this research, corrosion protection mechanism of 1 wt% Polyaniline nanoparticles in the Epoxy matrix was investigated by the application of scanning Kelvin probe (SKP). The potential difference between the tip and sample wich was defined as Volta potential was measured by SKP. potential decrease is an apparent phenomenon caused by corrosion induced Fermi level misalignment at the interface between the tip and the Iron substrate. It was proved that Polyaniline nanoparticles in the coating could stabilize the potential of metal in passive state via formation of protective oxide layer on the metal so that corrosion rate beneath the coating decreased.

Polyaniline nanoparticles-Scanning Kelvin probe-Surface Volta potential- Epoxy