Electrodeposition of sol-gel films on Al for corrosion protection.

Citation:

Sheffer M, Groysman A, Mandler D. Electrodeposition of sol-gel films on Al for corrosion protection. Corros. Sci.Corrosion Science. 2003;45 (12) :2893 - 2904.

Date Published:

2003///

Abstract:

Sol-gel films were electrodeposited on Al electrodes following the methodol. the authors have developed and is based on applying neg. potentials. This increases the pH at the surface, causing acceleration of the polymn. The authors' process follows the two step method, in which the monomer is 1st hydrolyzed in acidic soln. (pH ∼ 4) and only then the neg. potential is applied, which consumes protons and releases hydroxyl ions, thus enhancing the condensation. Films made of different monomers, i.e., tetraethoxysilane (TEOS), Me trimethoxysilane and Ph trimethoxysilane (PTMOS), were prepd., characterized and examd. for their corrosion inhibition properties. Potentiodynamic polarization, electrochem. impedance spectroscopy, optical and SEM as well as at. force microscopy were used as a means of film characterization. Hydrophobic and steric silanes, such as PTMOS showed a considerable corrosion inhibition capacity as compared to the capacity exhibited by less hydrophobic and steric derivs. such as TEOS. The difference between the conventional dip-coating method and the electrodeposition approach for depositing sol-gel films was also examd., indicating a clear advantage of the latter. [on SciFinder(R)]

Notes:

CAPLUS AN 2003:938266(Journal)