E. Mccafferty et Jv. Mcardle, CORROSION INHIBITION OF IRON IN ACID-SOLUTIONS BY BIOLOGICAL SIDEROPHORES, Journal of the Electrochemical Society, 142(5), 1995, pp. 1447-1453
Four siderophores isolated from bacteria have been studied as possible
corrosion inhibitors for iron in deareated 1N HCl. These compounds ar
e aerobactin, enterobactin, parabactin, and rhodotorulic acid. Polariz
ation measurements and ac impedance studies show that all four compoun
ds are inhibitors, with the order of effectiveness being rhodotorulic
acid < aerobactin < enterobactin < parabactin. X-ray photoelectron spe
ctroscopy surface analysis with one of the siderophores, rhodotorulic
acid, shows that it chemisorbs at the iron/HCl interface. Enterobactin
and parabactin are the most effective corrosion inhibitors of the fou
r because they have the optimum combination of relatively high values
of pK(al) and the largest molecular cross-sectional areas.