Water-based epoxy coatings with pH-sensitive TiO₂ containers for active corrosion protection of carbon steel

Abstract

Smart containers can be produced with polyelectrolyte multilayers that can release inhibitors in response to environmental changes at the coating defects. In this study, mesoporous TiO 2 hollow spheres were adopted as carriers for the encapsulation of corrosion inhibitor. The inhibitor-loaded TiO 2 containers were modified by polyelectrolyte shells using layer-by-layer self-assembly technology. The release behaviour of the encapsulated inhibitor was investigated using UV-visible spectroscopy. Corrosion protection performance of the epoxy coating with polyelectrolyte-modified TiO 2 containers was studied using electrochemical impedance spectroscopy and scanning Kelvin probe (SKP) techniques. Epoxy coating with the polyelectrolyte-modified TiO 2 containers provided better barrier properties than that of the blank coating. Waterborne epoxy coating impregnated with the polyelectrolyte-modified TiO 2 containers presented a significant self-healing effect after immersion in 0.5 M NaCl solution from the SKP results.

Phosphate loaded layered double hydroxides for active corrosion protection of carbon steel

“…However, the decrease of R po value of coating with LDH-PO 4 is comparatively slower than that of blank coating. R ct reflects the kinetics of electrochemical reactions at the interface, and a high R ct value denotes a low corrosion rate according to the literature [25]. The R ct value of the blank coating is 5.1 × 10 6 Ω cm 2 after 24 h immersion and decreases to 3.7 × 10 5 Ω cm 2 after 168 h of immersion.…”

Inhibitors Incorporated Into Water-Based Epoxy Coatings on Metals for Corrosion Protection: A Review

“…Another polyelectrolyte nanocapsule modified TiO 2 hollow spheres were used as an inhibitor containing container synthesized by a layer-by-layer mechanism. For this nanocontainer, maximum release behavior was obtained in an alkaline medium [97]. TiO 2 nanocontainer was also used for the encapsulation of mercaptobenzimidazole and it was modified using a SiO 2 covering.…”

Development and experimental verification of innovative corrosion protection epoxy coatings for steel

“…Previous studies have reported a variety of findings regarding the effectiveness of corrosion-resistant coatings. Liu et al (2020) found that polyelectrolyte-modified TiO 2 containers exhibit better corrosion protection performance than blank coatings. They also observed that a water-based epoxy coating impregnated with modified TiO 2 containers exhibited enhanced self-healing characteristics.…”

“…In recent years, considerable progress has been made in the development of new corrosion-protection coatings and the formulation of various corrosion-resistant alloys (Pande and Parikh, 2013; Hasannejad et al , 2013; Suleiman et al , 2013; Wang et al , 2013; Kouhi et al , 2013). Some new developments provide effective means of reducing the damaging effects of corrosion on steel (Liu et al , 2020; Zhou et al , 2023a; Fakhri et al , 2023; Garcia-Cabezon et al , 2020; Gautam et al , 2022; Kaya et al , 2023).…”