In seawater, severe corrosion occurs in all types of stainless steel, including 304 SS, which can lead to serious problems [1]. Therefore, surface functionalization has aimed at improving specific responses of 304 ss when interacting with seawater environment. Inspired from mussels, Polydopamine (PDA) adhere all types of surfaces. PDA coating are reported as promising anti-corrosion candidate for various metallic substrates [2]. The corrosion protection can be enhanced by addition of other protective layers [3]. In this study, the double layer coating comprising an upper layer of PDA and an inner layer of L-glycine as environmental friendly green inhibitor allowed to obtain noble protective layers that delay corrosion propagation on 304ss in simulated seawater. The inhibitory properties of the coatings were verified by Potentiodynamic polarization measurements and revealed a shift toward positive value of the corrosion potential and reduced corrosion current density of bare 304 ss. The Tafel extrapolation can be used to determine the corrosion rate of substrate. The corrosion potential for the bare, Glycine (0.1M) and Glycine (0.1M)/PAD coated 304ss in 3.5% NaCl solution are -0.27V,-0.2V and -0.13V, respectively. The Tafel analysis of Glycine (0.1M)/PDA reveal more inhibitory efficiency (85%) in comparison with Glycine(0.1M) alone (75.3%).
