Self‐healing silane coatings of cerium salt activated nanoparticles

Abstract

This work investigates the effect of cerium salt activated nanoparticles as nanoreservoirs on the self-healing properties of silane hybrid coatings deposited on electro-galvanized steel substrates. The substrates were pre-treated with 3-glycidoxypropyl-trimethoxysilane (GPTMS) and bisphenol A (BPA), modified with cerium ion-activated CeO2-ZrO2 and CeO2-SiO2 nanoparticles. The morphology of the coating before corrosion tests was examined using atomic force microscopy (AFM). The results indicate the formation of nanostructured surfaces with relatively uniform dispersion of nanoparticles in the silane coating containing CeO2-ZrO2 nanoparticles. The corrosion behavior of the sol-gel coatings was also investigated using salt spray tests, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization tests. During the salt spray test, the samples are exposed 600 h (or 25 days), revealing the improved resistance of the coated substrate containing CeO2-ZrO2 nanoparticles. Incorporation of activated CeO2-ZrO2 nanoparticles reduces the cathodic and anodic current density by one order of magnitude and shifts the corrosion potential to more positive values compared with the coating containing CeO2-SiO2 nanoparticles. Also, the EIS test results revealed higher impedance for the coating containing activated CeO2-ZrO2 nanoparticles. Corrosion tests results suggest that the activated CeO2-ZrO2 nanoparticles are more effective as nano-structured cerium ion reservoirs and can provide prolonged release of the inhibitor ions

Corrosion mechanism and kinetics of Al-Zn coating deposited by arc thermal spraying process in saline solution at prolong exposure periods

“…After 1 h of exposure, the impedance values of coating are extremely low at the low studied frequency (i.e., 0.01 Hz) as shown in Fig. 5b due to the presence of defects that enhance the dissolution 60 . However, when the exposure periods increase, the impedance values gradually increase, and this is potentially due to the transformation and deposition of corrosion products on coating surface.…”

Methods of Modifying Anticorrosive Protective Properties of Silane Films

“…Another important achievement in improving film growth and its corrosion performance was reported by doping silane films with nanoscaled inert particles, e.g. SiO 2 [53], CeO 2 [54,55], and TiO 2 [56,57], CeO 2 •ZrO 2 , [58], ZnO [59], Al 2 O 3 [60]. Most of the authors confirmed that the presence of the nanoparticles increases the thickness of the silane layer and contributes to the blockage of conductive pathways through the silane layer, hindering the electrolyte uptake (pore blocking effect).…”

“…The literature reports that the combination of ceria nanoparticles and cerium ions [21] or silica nanoparticles and lanthanum ions [68] creates a synergistic effect that significantly improves the anticorrosive properties of silane films. The corrosion tests conducted by Zandi Zand et al [58] suggest that activated CeO 2 -ZrO 2 nanoparticles are more effective as nanostructured cerium ion reservoirs and can provide prolonged release of inhibitor ions.…”

The Use of a Saturated Long Carbon Chain Sodium Monocarboxylate for the Corrosion Inhibition of Lead Objects in Atmospheric Conditions and in Acetic Acid Corrosive Solutions

“…This is probably due to the corrosion that occurs as a result from the arrival the corrosive solution to the lead metal surface. After 96 h, the phase angle shows a stability which can be attributed to the insoluble corrosion products that might hinder the electrolyte to pass to the lead metal surface [43].…”