School of Physical Sciences
Permanent URI for this collection
Browse
Browsing School of Physical Sciences by Author "Akalezi, Chris O."
Now showing 1 - 6 of 6
Results Per Page
Sort Options
Item Open Access Application of aqueous extracts of coffee senna for control of mild steel corrosion in acidic environments(Springer, 2012-07-16) Akalezi, Chris O.; Enenebaku, Conrad K.; Oguzie, Emeka E.Background: The inhibitive effect of the aqueous extract of Coffee senna (CS) on the corrosion of mild steel in 1 MHCl and 0.5 M H2SO4 solutions was investigated by weight loss measurement as well as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. Result: The extract was found to efficiently inhibit the corrosion process in both environments and inhibition efficiency increased with extract concentration as well as rise in temperature. Data from electrochemical measurements suggest that the extract functioned by adsorption of the organic matter on the metal/corrodent interface, inhibiting both the anodic and cathodic half reactions of the corrosion process. Adsorption of the extract organic matter was approximated by the Langmuir isotherm. The adsorption behavior of selected organicconstituents of the extract on the metal surface was assessed at the molecular level, in the framework of the density functional theory. Conclusion: This study clearly shows the potentials of CS extract for control of mild steel corrosion in acidic environment.Item Open Access Chemical interactions of synthetic and natural remediating agents with crude oil on agricultural soil(Pelaga Research Library, 2014) Ogukwe, Cynthia E.; Oze, Gabriel O.; Enenebeaku, Conrad E.; Akalezi, Chris O.Altered chemical system of an Agricultural Soil resulting from crude oil spillage was subjected to NPK fertilizer and compost manure for remediation. The effect of the remediating agents was observed in-situ by examining the soil parameters before, during and after the interactions. An Ultraviolet(UV) Spectrophotometer V180 was used for the evaluation of the Total Hydrocarbon content of the soil. Remediated state of 92.5% TPH reduction, pH, moisture balance and soil restoration was achieved with a combination of 150g NPK fertilizer and 150g compost manure per meter square (300g remediating agent /m2) plot of land, after seven weeks of application.Item Open Access Corrosion inhibition of aluminium pigments in aqueous alkaline medium using plant extracts(Canadian Center of Science and Education, 2012) Akalezi, Chris O.; Ogukwe, Cynthia E.; Enenebaku, Conrad K.; Oguzie, Emeka E.This work examines the efficacy and efficiency of Bucolzia coriacea (BC) and Cninodoscolus chayansa (CC) plants extracts as corrosion inhibitors for aluminum pigments using gas volumetric technique. The results obtained from this study indicate that all the extracts inhibited the corrosion process by extending the latency periods of the aluminum pigment-extract mix far beyond that of the bare aluminum pigment. Inhibition efficiency obtained was not only concentration dependent but also plant dependent and followed the order: BC>CC. A linear correlation was obtained between inhibition efficiency and duration of latency for each extract. Molecular modeling was used to evaluate the structure, electronic reactive parameters of the plant extracts in relation to their effectiveness as corrosion inhibitors.Item Open Access Evaluation of anticorrosion properties of Chrysophyllum albidum leaves extract for mild steel protection in acidic media(Springer Open, 2016-03) Akalezi, Chris O.; Oguzie, Emeka E.Background: The inhibition efficiency of Chrysophyllum albidum extract in controlling corrosion of mild steel in 1 M HCl has been evaluated by weight loss, potentiodynamic polarization and electrochemical impedance techniques at 303 K. The effect of immersion time and temperature on inhibition efficiency of the extract was also studied. Results: Inhibition was found to increase with increasing concentration of the extract but decrease with increasing time and temperature. Data from electrochemical measurements suggest that the extract functioned by adsorption of the organic matter on the metal/corrodent interface, inhibiting both the anodic and cathodic half reactions of the corrosion process. The increase in concentration of the inhibitor causes an increase in the activation energy and a decrease in the exponential factor k. Conclusion: The plant extracts follow Langmuir adsorption isotherm. Moreover, the process of adsorption is spontaneous, stable and considered to be physical adsorption. the thermodynamic properties recorded suggest that the process of film formation is higher than the destruction of the metal surface and that the adsorption process is exothermic.Item Open Access Gas chromatography-spectrophotometric (GC- MS) studies on therapeutic potentials of costus afer ker gawl leaves(U. P., 2018) Ogukwe, Cynthia E.; Akalezi, Chris O.; Anukam, Basil N.; Idika, Idika D.; Awosu, Emmanuel A.The ethanol leaf extract of Costus afer was subjected to qualitative phytochemical screening, column chromatography and GC-MS analysis to ascertain the compounds that exhibit anti-inflammatory and anti-oxidant properties as claimed by herbalists and traditionalists. The presence of Flavonoids, Saponins, Steroids, Terpenoids and Anthraquinones were indicated in the phytochemical screening. Eluent fractions from the moderately polar solvent of the column chromatography generated Gas Chromatogram that had 6 prominent peaks indicated that the prevailing compounds were oxirane hexadecyl (4.09%), n-Hexadecanoic acid(3.68%), 9-octadecenoic acid (z)- methyl ester(3.08%), 6-octadecenoic acid (z)- (13.49%) and two pentacyclic compounds identified as Cycloursan-3-ol, acetate (36.17%) and lupenone (39.50%). The two pentacyclic compounds confirmed the presence of steroids and validates the use of C.afer leaf for anti inflammatory therapy and as an antidote for acute toxi.Item Open Access Natural products for materials protection: Corrosion and microbial growth inhibition using capsicum frutescens biomass extracts(American Chemical Society, 2012-12-17) Oguzie, Emeka E.; Oguzie, Kanayo L.; Akalezi, Chris O.; Udeze, Irene O.; Ogbulie, Jude N.; Njoku, Victor O.Extracts of the fruit of Capsicum frutescens (CF) were assessed for anticorrosion and antimicrobial activity. The anticorrosion effect of the ethanol extract on low carbon steel in acidic media was studied experimentally using gravimetric, impedance, and polarization techniques, while the antimicrobial efficacy of ethanol, methanol, water, and petroleum spirit extracts respectively against the corrosion-associated sulfate reducing bacteria (SRB), Desulfotomaculum species, was assessed using the agar disc diffusion method. CF extract effectively inhibited both corrosion and SRB growth due to the action of the phytochemical constituents present therein, including alkaloids (8.8%), tannins (0.4%), and saponins (39.2%). The corrosion process was inhibited by adsorption of the extract organic matter on the steel surface, whereas the antimicrobial effect results from disruption of the growth and essential metabolic functions of the SRB. Molecular dynamics (MD) simulations were performed to theoretically illustrate the electronic structure and adsorption behavior of the active alkaloidal constituents of CF extract, capsaicin and dihydrocapsaicin, and afforded molecular level insights on their individual contributions to the corrosion inhibiting action of the extract