L. Garrigues et al., AN INVESTIGATION OF THE CORROSION INHIBITION OF PURE ALUMINUM IN NEUTRAL AND ACIDIC CHLORIDE SOLUTIONS, Electrochimica acta, 41(7-8), 1996, pp. 1209-1215
This work is devoted to the corrosion inhibition of pure aluminum by 8
-hydroxy-quinoline (8-HQ). In neutral solutions, steady-state current-
voltage curves and electrochemical impedance measurements show that th
e passive alumina layer is strengthened, particularly for long immersi
on times. The formation of a complex aluminum chelate explains the ele
ctrochemical results. Surface analysis indicates that in the presence
of 8-HQ, the oxide film is very thin; the adsorption of the organic co
mpound prevents the adsorption of chloride ions and the destruction of
the aluminum oxide layer. In acidic solutions, 8-HQ does not modify t
he corrosion mechanism of aluminum. This result is explained by the so
lubility of the aluminum chelate in acidic media. This is confirmed by
XPS analysis which also reveals a significant adsorption of the organ
ic molecule on the surface.