Superior anti-corrosion and self-healing bi-functional polymer composite coatings with polydopamine modified mesoporous silica/graphene oxide

In this article, graphene oxide (GO) and benzotriazole-loaded mesoporous silica nanoparticles (BTA/MSNs) are combined on micro scale through the in situ polymerization of polydopamine (PDA), preparing a selfhealing bi-functional GO (fGO) used as nano-fillers for anti-corrosion enhancement of waterborne epoxy (WEP) coatings. Scanning electronic microscopy (SEM) images show that the BTA/MSNs are uniformly distributed on the surface of high aspect ratio GO nanosheets to endow GO nanocontainer characteristics. UV-vis profiles demonstrate that fGO has pH-controlled release function. Modulus at lowest frequency is generally used for comparing the corrosion resistance of organic coatings. Modulus at lowest frequency (1.42 x10(7) Omega cm(2)) after 30 days immersion in 3.5 wt.% NaCl solution revealed 2 orders of magnitude higher that of blank WEP (1.17 x10(5) Omega cm(2)). With artificial cracks on its coatings, fGO/WEP had no obvious rust compared with blank WEP after 240 h of immersion. We anticipate that self-healing and physical barrier bi-functional nanocontainers improve the traditional anticorrosion coating efficiency with better, longer-lasting performance for shipping, oil drilling or bridge maintenance. (C) 2021 Published by Elsevier Ltd on behalf of Chinese Society for Metals.

Automated summary

In this study, graphene oxide and benzotriazole-loaded mesoporous silica nanoparticles were combined through in situ polymerization of polydopamine to prepare a self-healing bi-functional graphene oxide for enhancing the anti-corrosion properties of waterborne epoxy coatings. The new nanofillers demonstrated significantly improved corrosion resistance and self-healing capabilities for the coatings.