synthesis and application of polydopamine as bio-compatible corrosion inhibitor for steel substrate in 3.5 wt.% nacl solution.

Polydopamine has had an extensive interest in the last years due to its attractive structure and high potential to adhere to metal and other surfaces. due to these unique properties pda has been considered as high potential corrosion bio-inhibitor. in the current study, pda was synthesized via three different methods. pda1 was prepared in the water solvent, and with air oxidant, pda2 was also prepared in the water solvent and with sodium periodate oxidant, and in the pda3, water/methanol was used as mix solvent, and was added as an oxidant. three synthesized pdas were added to the 3.5 wt.% nacl solution separately and eis test was conducted after 24 h immersion time on the mild steel sample to investigate the corrosion inhibition behavior of these biopolymers. according to the nyquist plots (fig. 1-a), pda2 showed higher corrosion inhibition efficiency (71%) that others. according to the fe-sem image (fig. 1(b-d)), pda2 reveals a compact structure with lower porosity surface film compared with pda1 and pda2 that responsible for better coverage of the sample surface and better corrosion inhibition performance. in the comparison between pda1 and pda3, higher corrosion resistance was related to the pda3 due to the lower porosity and dense formed film.

Synthesis and Application of Polydopamine as bio-compatible corrosion inhibitor for steel substrate in 3.5 wt.% NaCl solution.

Polydopamine has had an extensive interest in the last years due to its attractive structure and high potential to adhere to metal and other surfaces. Due to these unique properties PDA has been considered as high potential corrosion bio-inhibitor. In the current study, PDA was synthesized via three different methods. PDA1 was prepared in the water solvent, and with air oxidant, PDA2 was also prepared in the water solvent and with sodium periodate oxidant, and in the PDA3, water/methanol was used as mix solvent, and was added as an oxidant. Three synthesized PDAs were added to the 3.5 wt.% NaCl solution separately and EIS test was conducted after 24 h immersion time on the mild steel sample to investigate the corrosion inhibition behavior of these biopolymers. According to the Nyquist plots (Fig. 1-a), PDA2 showed higher corrosion inhibition efficiency (71%) that others. According to the FE-SEM image (Fig. 1(b-d)), PDA2 reveals a compact structure with lower porosity surface film compared with PDA1 and PDA2 that responsible for better coverage of the sample surface and better corrosion inhibition performance. In the comparison between PDA1 and PDA3, higher corrosion resistance was related to the PDA3 due to the lower porosity and dense formed film.