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

Effect of dissolved CO₂ and Syzygium malaccense leaf DNA concentrations on carbon steel within a carbonic acid equilibrium

Oluranti Agboola, Boluwatife Bakre, Olagoke Oladokun, Augustine Omoniyi Ayeni, Ojo Sunday Isaac Fayomi, Olayemi Odunlami, Rotimi Sadiku, Amos Adeniyi, and Patricia Popoola

Department of Chemical Engineering, Covenant University, Ota, Nigeria

E-mail: funmi2406@gmail.com

Received: 6 February 2022  Accepted: 4 May 2022

Abstract:

The corrosion of CO₂ is a multifaceted process. This study investigated the impact of Syzygium malaccense DNA in combating the corrosion of dissolved CO₂ in water on mild steel. The increase in the concentration of CO₂ and of course the carbonic acid increases the corrosion rate of mild steel by speeding up the cathodic reaction. However, with regards to inhibitor efficiency, no evidence was found for a direct reaction of CO₂ on mild surface. The adsorption of Syzygium malaccense DNA inhibitor in all the concentrations of dissolved CO₂ media on mild steel surfaces obeyed the Freundlich adsorption isotherm as all linear correlation coefficient (R²) values were close to 1. The inhibition mechanism was ascribed to the electrostatic interaction ensued amid the negatively charged surface of the mild steel and the positively charge DNA inhibitor molecule. All surfaces of tested samples were characterized by XRD and SEM. The 0 mg/L DNA in 1627 mg/L dissolved CO₂ led to formation of high rough surface. The XRD patterns depict that the mild steel mainly constitutes Fe and FeCO₃.

Keywords: Syzygium malaccense DNA; Dissolved CO2; Inhibition mechanism; Adsorption isotherm; SEM; XRD

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02268-z

Chemical Papers 76 (9) 5497–5511 (2022)