External corrosion by soil’s components is a serious problem in many steel structures such as pipelines and tanks, thus many methods are applied to reduce this risk. Nanotechnology almost gives improving for conventional protection methods.
Investigation on nano Al2O3 doped polypyrrole coating has been done on carbon steel structures to protect them in two simulated soil environments include (0.01M NaCl + 0.01M NaHCO3) and (0.01M NaCl + 0.01M Na2SO4). Electropolymerization of pyrrole monomer carried out in oxalic acid with suspended nano alumina using cyclic voltammogram method. Characterization of produced film was done by SEM/EDS and the results indicated the uniformly distribution of coating in the presence of nano alumina confirming the presence of Al2O3 NPs by EDS analysis. Also FTIR spectra showed the occurred incorporation between polypyrole and nanoalumina in deposited film on steel surface.
The presence of nano alumina behaves as repaired to healing the defects in polymer film by chemical, mechanical and electrochemical factors and then gives long life time for service; this result was concluded through the improving in protection efficiency of Al2O3 NPs/PPy film compared with conventional red paint which is uses to protect carbon steel structures.