ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Chemical and microstructural investigation of starch modified zinc oxide paired as a composite superhydrophobic coating for mild steel protection

Oluwamayomikun D. Akinfenwa, Ojo S. I. Fayomi, Joshua O. Atiba, and Benjamin E. Anyaegbuna

Department of Mechanical Engineering, Bells University of Technology, Ota, Nigeria

E-mail: mayokundaniel17@gmail.com

Received: 26 July 2023  Accepted: 13 September 2023

Abstract:

Mild steel is one of the most common construction materials used in the mechanical and marine engineering sectors to handle acid, alkali, and salt solutions. One means of preventing corrosion on mild steel is coating, and the most significant designed coatings that have gained attention due to its numerous applications is superhydrophobic coating using electroplating method. This deposition was performed using 5 samples of mild steel substrate as the cathode, two zinc bars as the anode and sulfate bath solution as the electrolyte. Each sample was coated using voltage of 1.5 V and current density of 0.3173 A/cm², supplied by a DC rectifier for a coating period of 15 min per sample, and temperature of 45 °C by a magnetic stirrer. Starch addictive was added from 0 to 5 g into the electrolyte to form Zn-ZnO-Starch deposition. The depositions were characterized for pitting corrosion using potentiodynamic polarization techniques and SEM/EDS for microstructural properties. The phase transition was done with X-ray diffraction. From the results, Zn-ZnO control sample indicates high corrosion rate of about 14.311 mm/year. However, for Starch Zn-ZnO iterations, the corrosion rate reduced between 7.8024 and 11.006 mm/year. The SEM/EDS microstructural imaging shows more dispersive starch granules on the sample with 4.5 g Starch conc. over the sample with 1.5 g Starch conc., an indication of a strengthening characteristics. Sharp peak in XRD pattern indicates FeO, FeO₂ crystallites on ZnO profile with stable phase.

Keywords: Mild steel; Electrodeposition; Corrosion; Superhydrophobic coating; Zinc oxide

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-03091-w

Chemical Papers 77 (12) 7643–7651 (2023)