An in-depth comprehension of the protection mechanism of Al alloysby aniline-based silane

The protection mechanism of Al alloys by aniline-based silane (AnSi) was investigated by different experi-mental approaches. In particular, spectroscopic techniques were used for studying the chemistry of AnSisolution as a function of pH and water content, as well as in the presence of different metal ions. Inaddition, monitoring of structural changes of AnSi-based films deposited on different Al alloys duringexposure to mild aggressive conditions (humidity and laboratory environments) was carried out. Electro-chemical techniques, namely impedance measurements (Mott–Schottky analysis) and potentiodynamicpolarization were applied for investigating relationships between the semiconductor behavior and theprotection capacity of AnSi-based films in NaCl. Overall results converge to confirm that the protectioncapacity of the hybrid AnSi-based films is strictly determined by both charge transfer N H· · ·N complexesand metal–aniline interactions during the surface treatment step.