Designing of anti-corrosive poly (γ-glycidoxypropyltriethoxysilane)-coated aluminum alloy via electro-polymerization: effect of cerium nitrate concentration.

This study aims to evaluate the effect of cerium nitrate as an additive to the polymerization solution on the physico-chemical and anti-corrosion properties of sol–gel γ-glycidoxypropyltriethoxysilane polymers (GPS) applied onto AA2024-T3 aluminum alloy. The polymerization solution was prepared from a mixture of silane precursor and Ce(NO3)3 with a concentration ranging from 0 to 10−1 M. The coatings were electrodeposited by chronoamperometry at an applied potential of − 0.80 V/SCE. Their morphologies were examined by Scanning Electron Microscopy (SEM). The relative chemical compositions were characterized using Attenuated Total Reflectance Infrared Spectroscopy (FTIR-ATR) and X-ray Diffraction (XRD). Electrochemical impedance spectroscopy (EIS) was carried out to assess coating corrosion behaviors in a 5 × 10−2 M NaCl solution. Results showed that the addition of Ce(NO3)3 affected the uniformity, roughness, and thickness of the electrodeposited coatings. Furthermore, cerium improved the anti-corrosion performance of GPS film, particularly at a concentration of 3.3 × 10−2 M. This corrosion resistance resulted mainly from blocking the corrosion activity of the damaged surface through the formation of protective Ce oxides/hydroxides. [ABSTRACT FROM AUTHOR]