Evaluation of Bitter Kola Leaf Extract As an Anticorrosion Additive for Mild
RESEARCH ARTICLE V.C. Anadebe, P.C. Nnaji, N.A. Okafor, J.O. Ezeugo, F.E. Abeng and O.D. Onukwuli, 6 S. Afr. J. Chem., 2021, 75, 6–17, <https://journals.co.za/content/journal/chem/>. Evaluation of Bitter Kola Leaf Extract as an Anticorrosion Additive for Mild Steel in 1.2 M H2SO4 Electrolyte Valentine Chikaodili Anadebea,* §, Patrick Chukwudi Nnajib, Nkechinyere Amaka Okaforc, Joseph Okechukwu Ezeugoc, Fidelis Ebunta Abengd and Okechukwu Dominic Onukwulie aDepartment of Chemical Engineering, Federal University Ndufu Alike, Ebonyi State, Nigeria. bDepartment of Chemical Engineering, Michael Okpara University of Agriculture, Abia State, Nigeria. cDepartment of Chemical Engineering, Chukwuemeka Odumegwu Ojukwu University, Nigeria. dMaterial and Electrochemistry Unit, Department. of Chemistry, Cross River University of Technology, Calabar, Nigeria. eDepartment of Chemical Engineering, Nnamdi Azikwe University Awka, Anambra State, Nigeria. Received 24 January 2020, revised 29 August 2020, accepted 29 August 2020. ABSTRACT Plant-based material, namely bitter kola leaf, as an additive for surface modification of mild steel in H2SO4 solution was thoroughly scrutinized using electrochemical, theoretical and optimization techniques. The functional groups, of the biomolecules of the bitter kola leaf extract, were examined using Fourier transform infrared spectrometry (FTIR) and gas chroma- tography-mass spectrophotometry (GC-MS). For clarification purpose, scanning electron microscopy (SEM) was used to inspect the texture of the degraded and inhibited steel after 21 h of immersion. For the response surface methodology (RSM), central composite design of Design-Expert Software was used to optimize the inhibition efficiency as a function of acid concentration, inhibitor concentration, temperature and time. The optimum inhibition efficiency of 93 % was obtained at 0.9 g L–1 bitter kola leaf.
[Show full text]