Improvement of healing treatment with NaNO3 for a passivated iron electrode covered with an ultrathin polymer coating to prevent iron corrosion in some solutions containing aggressive anions

An ultrathin and ordered polymer coating was prepared on a passivated iron electrode by modification of a 16-hydroxyhexadecanoate ion HO ( CH 2 ) 15 CO 2 - self-assembled monolayer with 1,2-bis(triethoxysilyl)ethane (C2H5O)3Si(CH2)2Si(OC2H5)3 and octyltriethoxysilane C8H17Si(OC2H5)3. Further, the passivated and polymer-coated electrode was healed by treatment in 1.0M NaNO3 for 4h. Prevention of passive film breakdown and iron corrosion for the passivated, polymer-coated and healed electrode was examined by monitoring of the open-circuit potential and repeated polarization measurements in oxygenated 0.1M KClO4, 0.1M Na2SO4 and 0.1M NaCl for many hours. The values of the time for passive film breakdown, t