Facile size and chemistry-controlled synthesis of mussel-inspired bio-polymers based on Polydopamine Nanospheres: Application as eco-friendly corrosion inhibitors for mild steel against aqueous acidic solution

摘要

In recent studies, biopolymers such as chitosan and alginate have been applied as effective inhibitors for acidicinduced corrosion of metals. In this study, polydopamine (PDA) nanoparticles with different water stabilities, sizes, and chemistries were synthesized via three different methods (PDA-1, PDA-2, and PDA-3). The size, morphology, and chemistry of the PDA nanopartides were investigated by FE-SEM, FT-IR, UV-Visible and zeta potential methods. FE-SEM analysis revealed a significant size difference between the PDA particles obtained from the three methods. Finer particles were obtained for PDA-2 and PDA-3 samples. In addition, PDA-2 particles showed higher hydrophilic natures compared with PDA-1 and 3 due to the presence of large numbers of carboxylic groups in its structure. The inhibition abilities of the PDA-1, PDA-2 and PDA-3 particles against mild steel corrosion in 1 M HCl solution were studied by EIS and polarization methods. Results evidenced 93%, 99%, and 96% inhibition degrees in the solutions containing 5 mg/L PDA-1, PDA-2 and PDA-3 particles, respectively. Polarization test results evidenced that all PDA particles could suppress the steel corrosion via a mixed-type inhibition mechanism with a dominant anodic effect. The generation of a dense film composed of PDA particles on the steel substrates subjected to the HCl solutions was demonstrated by SEM analysis results. (C) 2019 Elsevier B.V. All rights reserved.