College of Engineering
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Item EVALUATION OF THE CORROSION INHIBITIVE BEHAVIOUR OF PAWPAW FLUID ON A315 MILD STEEL AND A304 STAINLESS STEEL IN H2SO4 MEDIUM(Rasayan J. Chem., 14(4), 2022) Ayoola, Ayodeji Ayodele; Fayomi, O. S. I.; Akande, Godwin I,; Mgbahurike,Chinemerem F.In this research work, the evaluation of the corrosion inhibitive performance of pawpaw fluid on A315 mild and 304 stainless steels in 0.5M H2SO4 (through weight loss approach) was investigated. The investigation involved the effects of variation in the inhibitor concentrations (0 – 10 %vol/vol) on weight loss, corrosion rate, inhibitor efficiency and the morphological structure of the metal samples. The weight-loss method involved the subjection of metal samples to the corrosion process in the acidic medium for 21 days. The results of both weight loss and corrosion rates revealed that pawpaw fluid inhibitor with a concentration of 10 %vol/vol gave the highest inhibitor efficiency of 89.9% and 87.1% for A315 mild and A304 stainless steels respectively. Also, results obtained showed that Langmuir adsorption isotherm accurately described the behavior of the adsorption mechanism and the physical adsorption (spontaneous) nature of the inhibitor was justified by the negative values of ∆Gads. Chemical composition results and the SEM analysis revealed that stainless steel has better corrosion resistance performance in 0.5M H2SO4 medium compared to mild steel (under the same experimental condition).Item AReviewonPolymer Nanocomposites and Their Effective Applications in Membranes and Adsorbents for Water Treatment and Gas Separation(Membrane, 2021) Agboola, Oluranti; Fayomi, O. S. I.; Ayoola, Ayodeji Ayodele; Ayeni, Augustine Omoniyi; Alagbe, Edith E; Sanni, Samuel E; Okoro, Emmanuel E.; Moropeng, Lucey; Sadiku, Rotimi; Kupolati, Kehinde Williams; Oni, Babalola AisosaItem CORROSION INHIBITION OF A36 MILD STEEL IN ACIDIC MEDIUM USING Citrus paradisi Rind Inhibitor(Rasayan J. Chem., 15(3), 2022-07) Ayoola, Ayodeji Ayodele; Olulesho, S; Durodola, Bamidee; Agboola, o.; Oladokun, O.; Ayeni, A.; Fayomi, O. S. I.; Babalola, R.The effectiveness of grapefruit (citrus paradisi rind) peel powder as a green corrosion inhibitor on A36 mild steel in 0.5M H2SO4 was examined. Gravimetric tests, SEM-EDS, and adsorption isotherm techniques were used to determine the corrosion inhibition features of the inhibitor on the surface of A36 mild steel. The tests were carried out with variation in concentration of inhibitor (0–0.4 %w/v), corrosion temperature (301K and 318K), and corrosion time (3 12 hours). The findings demonstrated that citrus paradisi rind powder effectively inhibited the corrosion of A36 mild steel on the surface with maximum corrosion inhibition efficiency of 85% at 0.4 w/v% inhibitor concentration at 310K corrosion temperature. The SEM-EDS analysis established the presence of sulphur, nitrogen, and oxygen (organic constituents), as well as the formation of a protective coating on the mild steel surface. Langmuir adsorption isotherm was found suitable for the prediction of the adsorption of citrus paradisi rind inhibitor on the mild steel surface. The thermodynamic considerations (∆𝐻 and (∆𝑆) indicated that the inhibition of A36 mild steel corrosion (using citrus paradisi rind inhibitor) was an exothermic process and the inhibitor molecules were physically adsorbed on the metal surface.Item Mild steel corrosion control through locally sourced calcium oxide on zinc phosphating process(South African Journal of Chemical Engineering 44, 2023) Ayoola, Ayodeji Ayodele; Ajinomisanghan, Eworitsemogha; Durodola, Bamidee; Fayomi, O. S. I.Mild steel is vulnerable to corrosion, so its prevention is essential in order to sustain its wide applications in petroleum, food, electrical, chemical, and construction industries. This study investigated the corrosion control action of the locally sourced calcium oxide on the zinc phosphating process of mild steel. Varied concentrations of calcium oxide (0 – 2 g/L) and coating (phosphating) time (40–70 min) were considered during the phos phating of the pretreated mild steel samples at coating temperatures of 60 ◦ C and 80 were subjected to weight loss tests utilizing a solution of NaCl (3.5 wt.%) at 25 ◦ ◦ C. The phosphate samples C, in order to determine both the sample corrosion rates and corrosion inhibition efficiencies. As both the calcium oxide concentration and phosphating temperature increased, the results trend (in general) showed a decrease in corrosion rate and in crease in inhibition efficiency. Sample with the operating conditions of 70minutes coating time, 2.0 g/L calcium oxide in the bath at 80 ◦ ads C coating temperature exhibited the best inhibition efficiency of 81% and lowest corrosion rate of 0.029 mm/year. SEM analysis revealed that the crystals of the coated surface became finer and had a more surface coverage owing to the increase in the concentration of calcium oxide (from 0.7 to 2.0 g/L). ΔG values of close to -20 kJmol 1 obtained (from both Langmuir and Freundlich adsorption isotherms) revealed a spontaneous and physical adsorption process of calcium oxide on the sample surfaces. The calculated positive values of ΔH ads and ΔS ads established the phosphating (coating) process to be an endothermic process with increased randomness at the solid/liquid interface of the sample surface and bath solution.Item Corrosion Inhibition on Mild Steel using Zinc Phosphating Modified with Magnesium and Calcium Additives(Portugaliae Electrochimica Acta 44, 2026) Ayoola, Ayodeji Ayodele; Durodola, M. E.; Babalola, R.; Fayomi, O. S. I.; Okoji, A.; Agbeyegbe, G. A.; Obigwe, C.MS is a very versatile and useful alloy in metal industry, since it is available and affordable, but it is prone to corrosion. This study investigated MS corrosion inhibition by modifying Zn₃(PO₄)2 bath with MgO and, then, with combined MgO and CaO additives. Different phosphating times (40, 60 and 80 min) and T (65 and 80 °C) were considered. Ct from 0 to 1.8 g/L MgO and combined MgO/CaO additives were added to Zn₃(PO₄)2 bath. SEM analysis of the coated samples was carried out. The specimens were also immersed in 3.5 wt% NaCl, for WL testing. Obtained results showed that the highest IE(%) of 56% was obtained for the MS sample at a phosphating T of 65 °C and Ct of 1.8 g/L MgO additive. For combined MgO and CaO additive, an IE(%) of 32% was obtained, at 65 °C, with a Ct of 0.9 g/L. MgO and CaO adsorption process (separately and combined) onto MS followed Freundlich’s adsorption model. ΔG indicated a physical adsorption process, and ΔH indicated an exothermic adsorption process, while ΔS during coating revealed a decrease in the process randomness degree.