Assessment of Self-Healing Epoxy-Based Coatings Containing Microcapsules Applied on Hot Dipped Galvanized Steel

Abstract

This study focuses on the design, development, and validation of two coating systems for corrosion protection of hot dip galvanized steel substrates. The coatings consist of epoxy-based resin reinforced with core-shell microcapsules, either cerium oxide or cuprous oxide core and a polymeric shell doped with cerium ions. The effect of the modification of the epoxy resin with a liquid rubber polymer has also been studied. Corrosion studies via electrochemical impedance spectroscopy (EIS) revealed that the coatings have enhanced barrier properties. Moreover, EIS studies on coatings with artificial scribes, demonstrated an autonomous response to damage and a selfhealing effect. Heat-induced material re-flow has also been observed after exposure to temperature higher than the T g of the system, which offered an additional self-healing mechanism, partially inhibiting the underlying corrosion processes when the liquid rubber is present in the system.

The influence of size and healing content on the performance of extrinsic self‐healing coatings

“…Subsequently, the healing systems are embedded in the matrix of the coatings during their production process. 40,41 The containers are developed through capsules, hollow fibers, and vascular systems (Figure 1), which have different pros and cons. 42 This encapsulation method can be also used for the tailored release of antiviral chemicals.…”

A Review of Recent Developments in Coating Systems for Hot-Dip Galvanized Steel

“…As a basic component of rare-earth conversion film, rareearth ions can comprise relatively complex film compositions, which commonly contain a wide range of negative ions through different surface pretreatments of metal substrate, PH in solution, immersion time, concentrations of rare-earth ions in solution, and deposition temperature (Brachetti-Sibaja et al, 2011). It is recognized that rare earths can act as corrosion inhibitors via inhibiting cathode reactions (Karaxi et al, 2019). Among these rare-earth conversion films, films containing cerium or lanthanum ions are pervasive and their anti-corrosion properties and applications as pretreatment layers have been widely researched (Aldykewicz et al, 1995;?…”

“…However, direct oxidation of Ce 3+ to CeO 2 is impossible. In addition, the presence of H 2 O 2 can benefit the oxidation process, accelerating the formation of hydroxides and oxides of Ce (Karaxi et al, 2019). The second stage can be known as the rare-earth film formation and crack initiation stage, wherein the dissolution of metal continues along with the precipitation of hydroxide of cerium.…”

Corrosion Protection Evaluation of Mild Steel: The Role of Hybrid Materials Loaded with Inhibitors

“…Hollow nanocontainers of Ce x Ti y O z were fabricated with a combination of the synthetic procedures demonstrated in our previous studies [23,24]. A three-step procedure was followed.…”