Facile Hydrogels of AIEgens Applied as Reusable Sensors for In Situ and Early Warning of Metallic Corrosion

Abstract

Early detection of metallic corrosion is one considerable method to reduce imperceptible disasters nowadays. Fluorescent coatings with high sensitivity and long lifetimes for use in the early detection of metallic corrosion are in high demand, but they are presently difficult to prepare. Inspired by the chameleon's skin, which is capable of switching its color in different atmospheres sensitively and reversibly, we proposed herein a facile and universal all-in-one strategy of combining the fluorescent sensitivity and dynamic hydrogen bonds in a hydrogel to develop a reusable corrosion detection tape to cover metal surfaces. The fluorescent hydrogel tape was constructed using free radical copolymerization of monomers [hydroxyethyl methylacrylate (HEMA) and tetraphenylethene derivatives (TPEPy)]. Due to the aggregation-induced emission (AIE) behavior of TPEPy, the poly-(HEMA-co-TPEPy) hydrogel is capable of monitoring the traces of corrosion via the release of ferric ions with a concentration as low as 10 −5 M. Moreover, due to the dynamic hydrogen bonds of hydroxyethyl groups in hydrogel networks, the fluorescent hydrogel tape exhibited good adhesion and well reusability for over 10 applications to effectively warn against early corrosion of stainless steel. This non-destructive and reversible method of early corrosion detection can provide valuable signals when maintenance is needed before the metal suffers serious damage.

Stimuli‐responsive fluorescent hydrogels: Strategies and applications

“…(b) In situ pitting observation of stainless steel under sunlight and UV light. [119] Reproduced with permission.…”

“…Meng and coworkers [119] reported a fluorescent hydrogel that can effectively warn against early corrosion of stainless steel by monitering the concentration of Fe 3+ ions. The fluorescent hydrogel p (HEMA‐co‐TPEPy) was prepared by copolymerizing tetraphenylethene derivatives (TPEPy) monomer with 2‐hydroxyethyl methacrylate (HEMA) monomer via free radical polymerization (Figure 12).…”

“… (a) Schematic illustration of p(HEMA‐ co ‐TPEPy) hydrogel in response to ferric ions or EDTA. (b) In situ pitting observation of stainless steel under sunlight and UV light [119] . Reproduced with permission.…”

A New Imidazole Derivative for Corrosion Inhibition of Q235 Carbon Steel in an Acid Environment

“…Several methods have been explored to protect carbon steels from corrosion, including alloying [3], organic coatings [4], anodization [5,6], conversion coatings [7], and the use of inhibitors [8][9][10][11][12]. Among them, inhibitors have attracted significant attention due to their high efficiency, cost-effectiveness, and ability to provide corrosion protection without adversely affecting mechanical properties, as can be seen in the case of alloying methods [13].…”