مرضيه مصدق

Conductive polymer-based nanocomposite coatings are of great interest due to their unique properties, including protection of metals against corrosion, among conductive polymers, polypyrrole due to ease of synthesis, compatibility with the environment, and biocompatibility, and among nanofillers, graphene oxide due to its high protective properties. To improve the performance of polypyrrole, they were chosen to prepare nanocomposite coating. In this research, the corrosion resistance of titanium metal coated with polypyrrole/graphene oxide nanocomposite in a body-simulating fluid has been investigated. This coating was synthesized by electropolymerization method with a constant current of 1 mA/cm2 and a constant time of 600 seconds on a titanium substrate, to investigate the effect of graphene oxide in improving the properties of the polymer coating, graphene oxide with three different weight percentages of 1%, 3% and 5% to polypyrrole were added and finally four coatings PPy, PPy/GO1, PPy/GO2 and PPy/GO3 were compared. SEM images were used to identify the surface morphology of the coatings and the effect of GO on the morphology of polypyrrole, and the result of thickness measurement indicates the success of coating with a thickness of 6 microns. The structural interaction between polypyrrole and GO in the nanocomposite coating was studied by Raman and FT-IR analysis, and the GIXRD test showed the amorphous nature of the nanocomposite coating. The surface properties of the coatings were eva‎luated with the help of AFM images, nano hardness, and scratch test. The surface roughness of the coatings was checked using AFM images, and according to the results, 1% and 5% by weight of graphene oxide were selected as optimal values. By adding GO, the surface roughness and hardness of the coating have increased and the wear rate has decreased. Also, the contact angle test showed an increase in the hydrophilicity of the coating by adding GO to the polymer matrix. Finally, the corrosion resistance of the prepared coatings was studied with potentiodynamic polarization tests and electrochemical impedance spectroscopy. By adding GO to the polypyrrole matrix, the corrosion current density decreased and the inhibition percentage of nanocomposite coatings increased. Also, the results of electrochemical impedance spectroscopy showed a higher resistance for titanium with nanocomposite coating, and the coating with 1% by weight of graphene oxide was determined as the optimal coating in improving the corrosion resistance rate.

خوردگي , پوشش نانوكامپوزيتي , پلي‌پيرول , اكسيدگرافن , تيتانيوم

Corrosion , Nanocomposite Coating , Polypyrrole , Graphene Oxide , Titanium

marzieh mosadegh

Dr. Alireza Khavandi, Dr. Seyed Hossein Seyedein