Characterization of hybrid sol–gel films doped with red mud particles

Abstract

ABSTRACTThe present work deals with the characterization of a hybrid sol–gel coating doped with red mud (RM) particles. RM is the insoluble residue remaining after caustic digestion of bauxite by the Bayer process. Because of its high alkaline nature, together with the presence of Fe(III), we assume that this is a good corrosion inhibitor candidate. The hybrid sol–gel was made from tetra‐n‐propoxyzirconium as an inorganic precursor and 3‐glycidoxypropyltrimethoxysilane as an organic precursor. Sol–gel films were doped with 5% wt. of RM and deposited on an AA2024‐T3 alloy. Several techniques were used to study the system: Fourier‐transformed infrared spectroscopy, X‐ray photoelectron spectroscopy, time‐of‐flight secondary ion mass spectrometry, and zeta potential measurements. The results indicate that a good dispersion of the particles into the sol–gel film was obtained. Moreover, the zeta potential measurements revealed the ability of RM particles to capture chloride ions. Copyright © 2012 John Wiley & Sons, Ltd.