Mussel-inspired polydopamine (PDA)-chitosan (CS) bio-molecules grafted graphene oxide nano-platforms synthesis and application as sustainable smart anti-corrosion system

Abstract

In this paper, an innovative strategy was planned for the rational construction of a unique nanocarrier by surface modification of the GO flakes with bio-compatible/bio-degradable materials based on polydopamine (PDA) and chitosan (CS). The outcome of the TGA, UV–vis, FE-SEM/EDX, Raman, XRD, and FTIR analyses confirmed the successful adsorption of the polydopamine, chitosan, and zinc cations on the GO surface. Along with the ICP-OES and UV–vis spectra, the release of the PDA and CS molecules as well as Zn (II) ions from the GO nanolayers relies on the pH. The pH-activated release of the inhibitive compounds makes the GPCZ-containing (GO-PDA-CS-Zn) coating a suitable nanocomposite for self-healing purposes. The barrier and active corrosion protection properties of the composites in the attendance and absence of the synthesized nanoparticles were appraised by PDS and EIS techniques. The polarization diagrams disclosed that in the presence of GPCZ nanoparticles, the icorr value of the metallic substrate reduced from 4.07 (blank surface) to 0.359 μA cm−2 (GPCZ sample). The significant protection efficiencies in the scratched GPC and GPCZ/EP coatings were around 90% after 72 h denoting the active protection performance in addition to self-healing functioning. The Rct values of 0.003, 0.05, 4, 5, and 49 GΩ cm2 for the blank, GO, GP, GPC, and GPCZ coatings respectively after 77 days of immersion in the saline electrolyte show the excellent impact of the coating pigmentation in providing effective protection which inhibited the coating degradation and delamination.