Corrosion resistance performance of electrophoretically deposited graphite–chitosan composite coating on copper
SWARNIMA SINGH N USHA KIRAN LAXMIDHAR BESRA BIMAL PRASAD SINGH SRIPARNA CHATTERJEE
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Development of graphite and graphite–chitosan composite coating on copper (Cu) substrate is carried out using electrophoretic deposition. Further, post-treatment is done using ethanolic solution of 20 wt% methyl hydrogenpolysiloxane (KF-99) to improve coating adhesion with the copper substrate. The corrosion resistance of the post-treated coating is examined in 3.5 wt% NaCl solution. Field-emission scanning electron microscope reveals that the addition of chitosan leads to densification of the coatings. A reduction in the $I_D$/$I_G$ ratio of the graphite–chitosan composite coating compared to graphite coating implies a decrease in the defect in the coating. An increase in corrosion potential of 0.29 V isnoticed for graphite–chitosan composite coating compared to pure copper, i.e., –0.02 V. The corrosion rate is reduced to 34% for graphite coating (0.070 mmpy) and 51% for graphite–chitosan composite coating (0.050 mmpy) as compared topure copper (0.102 mmpy) substrate. The pure copper substrate shows the lowest polarization resistance ($R_p$ ${\sim}$ 40.23 ${\Omega}$.cm$^2$) that is drastically enhanced in the case of graphite–chitosan composite coating ($R_p$ ${\sim}$ 4327 ${\Omega}$.cm$^2$). Enhancementin the corrosion resistance of the graphite–chitosan composite-coated sample is attributed to the formation of a protective barrier layer of SiO$_2$ and chitosan, which acts as an obstacle to ion transportation between the copper substrate and NaCl solution.
SWARNIMA SINGH1 N USHA KIRAN1 2 LAXMIDHAR BESRA1 2 BIMAL PRASAD SINGH1 SRIPARNA CHATTERJEE1
Volume 46, 2023
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Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020
Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020
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