PAUL O AMEH | The Nigeria Police Academy ( University), Wudil, Kano, Nigeria (original) (raw)

Papers by PAUL O AMEH

Chemical constituents and functional groups in Ficus thonningii gum was determined using GCMS and... more Chemical constituents and functional groups in Ficus thonningii gum was determined using GCMS and FTIR spectropho-tometer, respectively. The GCMS spectrum of Ficus thonningii gum showed the presence of useful organic chemicals. The gum is mildly acidic, tasteless, yellowish in colour, insoluble in chloroform and acetone but soluble in water and ethanol. Based on its chemical constituents, the corrosion inhibition potential of the gum was investigated and it was found that the gum acted as an adsorption inhibitor for the corrosion of aluminium in solution of HCl. The adsorption of the gum on the surface of aluminium is spontaneous, exothermic and proceeded through the initial mechanism of physical adsorption. Deviation of the adsorption of the gum from the ideal Langmuir adsorption isotherm and the nature of adsorption were accounted for by Frumkin, El Awardy and Dubinin-Radushkevich (D-RIM) adsorption isotherms. The study provides information on the physicochemical constituents of t...

International Journal of Electrochemical Science, 2012

Chemical constituents of purified sample of Ficus platyphylla gum was investigated using GCMS tec... more Chemical constituents of purified sample of Ficus platyphylla gum was investigated using GCMS technique. The results obtained indicated the presence of methoxy-phenyl-oxime (0.79 %), 1

This study was carried out to determine the effect of lecture and demonstration methods on academ... more This study was carried out to determine the effect of lecture and demonstration methods on academic achievement of students in Chemistry in the Nassarawa Local Government Area of Kano State. Fifty eight (58) Chemistry students (boys and girls) in the Senior Secondary School One (SS1) from two randomly selected schools were involved in the study. Necessary data were collected and the validated reliable data were analyzed using t-test at a significant level of 0.05. Results obtained revealed that students perform better in Chemistry when taught using the demonstration method as compared to the lecture method. The boys and girls are better in academic achievement when taught using demonstration method than when lecture method was used. The demonstration method shows equality in the performance of boys and girls. Hence the adoption of demonstration methods in the teaching and learning of Chemistry and science in general is hereby recommended.

Batch adsorption studies were used to evaluate the adsorption capacity of Iraqi Palm Date in the ... more Batch adsorption studies were used to evaluate the adsorption capacity of Iraqi Palm Date in the removal of Cd(II) and Cu(II) ions from synthetic aqueous solutions was evaluated. The effects of adsorbent loads, contact time, initial metal concentration, pH and temperature have also been reported. The applicability of Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R) isotherm was tried for the system to completely understand the adsorption isotherm processes. The data fitted pseudo-second-order kinetic model with high correlation indicating that the adsorption processes were chemisorptions. The present data confirms that Iraqi Palm Date may be used as efficient adsorbent for the removal of cadmium (II) and copper (II) ions from aqueous solution.

The corrosion inhibition of zinc in 1.0 M H2SO4 solution by Cefuroxime axetil has been studied in... more The corrosion inhibition of zinc in 1.0 M H2SO4 solution by Cefuroxime axetil has been studied in relation to the concentration of the additive using weight loss measurement, Linear polarization resistant (LPR) and potentiodynamic polarization (PDP).The results indicate that Cefuroxime axetil inhibited corrosion reaction in the acid medium and inhibition efficiency increased with inhibitor concentration. The inhibitor was found to be adsorption inhibitor that best fitted the Langmuir adsorption model. From calculated values of activation energy, free energy of adsorption and the variation of inhibition efficiency with temperature, it was deduced that the adsorption of the inhibitor favours the mechanism of physical adsorption. The polarization data indicate that the inhibitor was of mixed type. The results obtained from LPR, PDP and weight loss measurements were in good agreement.

Hair samples collected from thirty-four (34) individuals in Wudil Local Government Area of Kano S... more Hair samples collected from thirty-four (34) individuals in Wudil Local Government Area of Kano State Nigeria with respected to age, sex and smoking habits were analyzed for trace metals (Ca, Zn, Cu, Cd, Cr, Mg and Pb) using Atomic Absorption Spectrophotometric (AAS) technique. The result obtained indicated the mean concentrations of trace metals in the human hair of both male and female respondent follow similar trend as Ca>Zn>Cu>Pb>Cr>Mg>Cd. The levels of Ca and Mg were found higher in female respondents compared to the men. Also, the standard deviation obtained for the level of Pb and Cd were higher in males while Cr was found to be higher in females. Cd and Ca shows a gradual increase as it rises thorough the studied age groups, and the abruptly drops at the last age group (≥ 41). Cu was also found to have the highest concentration in individuals of the highest age group (≥ 41). Age and smoking habits also had great influence on trace metal hair concentrations ...

Walailak Journal of Science and Technology, Jan 4, 2013

GCMS (Gas Chromatography Mass Spectrometry), FTIR (Fourier Transformed Infra-Red Spectroscopy), S... more GCMS (Gas Chromatography Mass Spectrometry), FTIR (Fourier Transformed Infra-Red Spectroscopy), SEM (Scanning Electron Microscopy), physiochemical and rheological analysis of Albizia zygia gum have been carried out. Albizia zygia exudate is a brownish in colour, acidic and ionic gum. GCMS spectra of the gum indicated the presence of (E)-methyl octadec-7-enoate (41.18 %), methyl palmitate (18.64 %), methyl stearate (19.13 %), (9E,12E)-methyl octadeca-9,12-dienoate (11.88 %), methyl icosanoate (1.85 %), 2,3-dihydroxypropyl oleate (2.05 %), (Z)-octadec-13-enal (1.63 %), 2hydroxy-3-(palmitoyloxy)propyl stearate (1.55 %), 2,3-dihydroxypropyl stearate (0.82 %), dimethyl phthalate (0.58 %) and 3-((aminomethoxy) (hydroxy)phosphoryloxy)propane-1,2-diyl dipalmitate (0.70 %). The FTIR spectrum of the gum indicated several functional groups, including-OH, CO and C=O. From the scanning electron micrograph, the morphology of the gum shows irregular shapes embedded on the surface. Rheological studies indicated that the viscosity of the gum increased with increasing pH but decreased with an increase in temperature. Application of Huggins, Kraemer and Tanglertpaibul and Rao models indicated that the intrinsic viscosity of the gum is in the range of 0.5-0.8. Plots obtained for the variation of viscosity with shear rate and shear rate with shear stress confirmed that Albizia zygia gum is a non Newtonian dilatant polymer with a characteristic shear thickening property.

International Journal of Metals, 2015

A comparative study of the inhibitory potentials of gum exudates from Albizia ferruginea (AF) and... more A comparative study of the inhibitory potentials of gum exudates from Albizia ferruginea (AF) and Khaya senegalensis (KS) on the corrosion of mild steel in HCl medium was investigated using weight loss and gasometric method. The active chemical constituents of the gum were elucidated using GC-MS while FTIR was used to identify the bonds/functional groups in the gums. The two gum exudates were found to be good corrosion inhibitors for mild steel in acidic medium. On comparison, maximum inhibition efficiency was found in Khaya senegalensis with 82.56% inhibition efficiency at 0.5% g/L concentration of the gum. This may be due to the fact that more compounds with heteroatoms were identified in the GCMS spectrum of KS gum compared to the AF gum. The presence of such compounds may have enhanced their adsorption on the metal surface and thereby blocking the surface and protecting the metal from corrosion. The adsorption of the inhibitors was found to be exothermic and spontaneous and fitt...

International Journal of Physical Sciences, Apr 30, 2014

Gas chromatographic-mass spectrometry (GCMS), fourier transformed infra-red spectroscopy (FTIR) a... more Gas chromatographic-mass spectrometry (GCMS), fourier transformed infra-red spectroscopy (FTIR) and physicochemical analysis of Commiphora kestingii gum have been carried out. The corrosion inhibition characteristics of C. kestingii (CK) gum on aluminium in sulphuric acid media were also investigated at 303 and 333K using gravimetric and scanning electron microscopic studies (SEM) method. The study revealed that the gum contains significant amount of Sucrose, Octadecanoic acid, Alpha camphorenal, Nerolidolisobutyrate, Diisopropenyl-1-methyl-1-vinyl cyclohexane, Abetic acid, Oleic acid, Verbenol, 2,6-dimethylhepta-1,5-diene, Naphthalene, Limonene, 7-hexadecenal and 10methyl-8-tetradecen-1-ol acetate. Corrosion inhibition tests suggest that GS gum is a good inhibitor for the corrosion of Al in solution of H 2 SO 4. The inhibition efficiency of this inhibitor increased with increasing temperature suggesting chemisorption mechanism. Also, the inhibition efficiency of these extract was found to increase in the presence of CK. Inhibition of Aluminium by C. kestingii gum occurred through synergistic adsorption of the various components of the gums hence the formation of multiple adsorption layer is proposed.

The inhibitive effect of Khaya ivorensis gum exudate (KI) for the corrosion of mild steel in HCl ... more The inhibitive effect of Khaya ivorensis gum exudate (KI) for the corrosion of mild steel in HCl medium has been evaluated using the weight loss, gasometric, and thermometric techniques. The inhibition efficiencies of the gum were found to increase with increasing concentration of inhibitors and decreased with increase in temperature, indicating that KI gum is a good adsorption inhibitor for the corrosion of mild steel in solution of HCl. The adsorption of inhibitor on mild steel surface is first order, exothermic, spontaneous and the adsorption characteristic of the studied inhibitor was best described by the Langmuir adsorption isotherm. Phenomenon of physical adsorption is proposed from the values of kinetic and thermodynamic parameters obtained.

Abstract:Studies on the corrosion inhibition potentials of ciprofloxacin were carried out using g... more Abstract:Studies on the corrosion inhibition potentials of ciprofloxacin were carried out using gravimetric, thermometric and scanning electron microscopy techniques. The inhibition efficiencies of ciprofloxacin for the corrosion of mild steel increased with increase in concentration but decreased with rise in temperature. The scanning electron microscopy shows that the damaging effect of the acid on the metal surface is greatly reduced with the presence of the inhibitor. This may probably be due to the formation of protective coverage by the inhibitor. Adsorption characteristics of the inhibitor has also been studied and it is found that ciprofloxacin inhibits the corrosion of mild steel by being adsorbed on the surface of mild steel by a physicaladsorption mechanism. The adsorption of ciprofloxacin on the mild steel surface was found to be spontaneous and obey the Langmuir adsorption isotherm model. Keywords:corrosion; mild steel; inhibitor; adsorption; ciprofloxacin.

Chemical Engineering Communications, 2014

ABSTRACT Physico-chemical constituents of GLORIOSA SUPERBA gum exudate were analyzed using recomm... more ABSTRACT Physico-chemical constituents of GLORIOSA SUPERBA gum exudate were analyzed using recommended chemical methods. Results obtained from FT-IR study indicated the presence of functional groups that are typical for polysaccharides. Gas chromatography-mass spectrometry spectrum of the gum revealed the presence of 1-piperoylp, 1-penta-decarboxylic acid, 9-octadecenoic acid, and stigmasta-5,22-dien-3-ol. Based on its chemical constituents, corrosion inhibition potentials of various concentrations of the gum were investigated using FT-IR and gravimetric methods. The results obtained showed that GLORIOSA SUPERBA gum is an inhibitor for the corrosion of Al in solution of HCl. The initial mechanism for the inhibition of Al corrosion by GLORIOSA SUPERBA gum was found to be physiosorption and was succeeded by chemisorption. Although the Langmuir adsorption model supported the adsorption characteristics of the gum, the existence of interaction between the inhibitor particles was confirmed by the fitness of Flory-Huggins, Parsons, and Volmer adsorption isotherms. Analysis of El-Awady et al. kinetic isotherm revealed the formation of multiple layers of inhibitor on the surface of Al. The adsorption strength of the inhibitor was also found to increase with increasing temperature. Data obtained from the application of the Gibb-Helmholtz equation and Bockris-Swinkle adsorption model reflected spontaneous adsorption of the gum on the Al surface through chemisorption. From quantum chemical studies, it was found that the adsorption of the gum on the Al surface is facilitated by the presence of amide and hydroxyl functional groups in stigmasta-5,22-dien-3-ol and 1-piperoylp respectively.

Asian Journal of Chemistry, 2013

Physicochemical studies on Anogeissus leiocarpus gum (AL gum) indicated that the gum is mildly ac... more Physicochemical studies on Anogeissus leiocarpus gum (AL gum) indicated that the gum is mildly acidic, ionic, odourless, yellowish-red and is soluble in water (but insoluble in ethanol, acetone and chloroform). The gum has significant concentration of essential elements (Mg, Ca, Fe, Cu, Mn) and low concentrations of heavy metals (Pb and Cd). The protein content of the sample was also found to be low (≈5 %). Scanning electron micrograph of the gum revealed that the gum is irregularly shaped and amorphous. Rheological study indicated that the viscosity of the gum increases with increasing pH and concentration but decreases with increase in temperature. The apparent activation energy of flow for Anogeissus leiocarpus gum (calculated fromArrhenius-Frenkel-Eyring plot) was 3.16 suggesting the presence of fewer inter and intra molecular interaction. Values of intrinsic viscosity obtained from Huggins and Kraemer plots were similar (8.82) while those obtained from Tanglertpaibul and Roa plots ranged from 3.50 to 11.82 dL/g. From the plot of speed of rotation versus viscosity, viscosity versus shear rate and shear stress versus shear rate, a non Newtonian behaviour (dilatant) with characteristics shear thickening property was verified for Anogeissus leiocarpus gum. Calculated ‘b’ value of 1.108 was obtained through the application of the power law equation and is associated with random coil conformation or entanglement. Analysis of the master's curve shows that random coil conformation or entanglement is proposed to occur at C[η]~ 4.0, i.e. at ηsp = 2.19 (ηrel = 3.19).

The adsorption of Cd(II) and Cr(VI) ions from synthetic solutions was performed using activated l... more The adsorption of Cd(II) and Cr(VI) ions from synthetic solutions was performed using activated locust bean husk (ALBH). The adsorption depends on temperature, pH of the solution, type of ions, initial concentration of metals and the adsorbent concentration. The equilibrium data were analyzed using Langmuir and Freundlich isotherm models. The maximum adsorption capacity of the adsorbent was in the range of 3.17 mg/g for Cd(II) and 4.13 mg/g for Cr(VI). The experimental results demonstrated that ALBH could be used for the removal of Cd(II) and Cr(VI) ions from aqueous medium through adsorption.

Examination of the physical (colour, odour, pH, solubility in various solvents) and chemical (GCM... more Examination of the physical (colour, odour, pH, solubility in various solvents) and chemical (GCMS and FTIR) characteristics of Ficus benjamina gum revealed that the gum is yellowish in colour, mildly acidic and ionic in nature. Major constituents of the gums were found to be sucrose and d-glucose, which constituted 60.92 % of their chemical constituents, while various carboxylic acids [(albietic acid (1.00%), hexadecanoic acid (4.41 %), 9-octadecanoic acid (1.00 %), octadecanoic acid (3.01 %), oleic acid (0.10 %), octadecanoic acid (9.12 %) and 6,13-pentacenequinone (20.43 %)] accounted for the remaining constituents. Functional groups identified in the gum were found to be those typical for other carbohydrates. From the knowledge of the chemical structures of compounds that constitute the gum, the corrosion inhibition potentials of the gum were ascertained and from weight loss analysis, the gum was found to be an active inhibitor against the corrosion of aluminum in solutions of t...

Ficus platyphylla gum exudates (FP gum) have been analyzed for their physicochemical parameters a... more Ficus platyphylla gum exudates (FP gum) have been analyzed for their physicochemical parameters and found to be ionic, mildly acidic, odourless, and yellowish brown in colour. e gum is soluble in water, sparingly soluble in ethanol, and insoluble in acetone and chloroform. e nitrogen (0.39%) and protein (2.44%) contents of the gum are relatively low. e concentrations of the cations were found to increase according to the following trend, Mn>Fe>Zn>Pb>Cu>Mg>Cd>Ca. Analysis of the FTIR spectrum of the gum revealed vibrations similar to those found in polysaccharides while the scanning electron micrograph indicated that the gum has irregular molecular shapes, arranged randomly. e intrinsic viscosity of FP gum estimated by extrapolating to zero concentrations in Huggins, Kraemer, Schulz-Blaschke, and Martin plots has an average value of 7 dL/g. From the plots of viscosity versus shear rate/speed of rotation and also that of shear stress versus shear rate, FP gum ...

The adsorption of Cd(II) and Cr(VI) ions from synthetic solutions was performed using activated l... more The adsorption of Cd(II) and Cr(VI) ions from synthetic solutions was performed using activated locust bean husk (ALBH). The adsorption depends on temperature, pH of the solution, type of ions, initial concentration of metals and the adsorbent concentration. The equilibrium data were analyzed using Langmuir and Freundlich isotherm models. The maximum adsorption capacity of the adsorbent was in the range of 3.17 mg/g for Cd(II) and 4.13 mg/g for Cr(VI). The experimental results demonstrated that ALBH could be used for the removal of Cd(II) and Cr(VI) ions from aqueous medium through adsorption.

Examination of the physical (colour, odour, pH, solubility in various solvents) and chemical (GCM... more Examination of the physical (colour, odour, pH, solubility in various solvents) and chemical (GCMS and FTIR) characteristics of Ficus benjamina gum revealed that the gum is yellowish in colour, mildly acidic and ionic in nature. Major constituents of the gums were found to be sucrose and d-glucose, which constituted 60.92 % of their chemical constituents, while various carboxylic acids [(albietic acid (1.00%), hexadecanoic acid (4.41 %), 9-octadecanoic acid (1.00 %), octadecanoic acid (3.01 %), oleic acid (0.10 %), octadecanoic acid (9.12 %) and 6,13-pentacenequinone (20.43 %)] accounted for the remaining constituents. Functional groups identified in the gum were found to be those typical for other carbohydrates. From the knowledge of the chemical structures of compounds that constitute the gum, the corrosion inhibition potentials of the gum were ascertained and from weight loss analysis, the gum was found to be an active inhibitor against the corrosion of aluminum in solutions of t...

International Journal of Electrochemical Science, 2011

GCMS study of Anogessus leocarpus gum (AL gum) indicated the presence of sucrose (10.03 %), phtha... more GCMS study of Anogessus leocarpus gum (AL gum) indicated the presence of sucrose (10.03 %), phthalic acid (2.53 %), n-hexadecanoic acid (11.73 %), oleic acid (30.49 %), pentacenequinone (4.41 %) and 2,3-diphenylnaphthoquinone (21.43 %). The gum was found to be a good adsorption inhibitor for the corrosion of mild steel in HCl solution. The adsorption of the inhibitor on mild steel surface is exothermic, spontaneous, Langmuir type and supports the mechanism of charged transfer from the inhibitor's molecule to the charged metal surface. FTIR study of the AL gum and the corrosion product of mild steel (in the presence of AL gum as an inhibitor) indicated the presence of interaction between the inhibitor and the metal surface (some shifts in frequencies of IR adsorption), some functional groups were used for the adsorption of the inhibitor onto the metal surface (missing functional groups) and others for the formation of Fe-inhibitor complex (new functional groups formed). The inhibition of mild steel corrosion is proposed to occur through synergistic combination of the constituents of the inhibitor, which facilitates the formation of multi-molecular layer of adsorption and the formation of inhibitor-metal complex, which protected the metal from further corrosion attack.

Chemical constituents and functional groups in Ficus thonningii gum was determined using GCMS and... more Chemical constituents and functional groups in Ficus thonningii gum was determined using GCMS and FTIR spectropho-tometer, respectively. The GCMS spectrum of Ficus thonningii gum showed the presence of useful organic chemicals. The gum is mildly acidic, tasteless, yellowish in colour, insoluble in chloroform and acetone but soluble in water and ethanol. Based on its chemical constituents, the corrosion inhibition potential of the gum was investigated and it was found that the gum acted as an adsorption inhibitor for the corrosion of aluminium in solution of HCl. The adsorption of the gum on the surface of aluminium is spontaneous, exothermic and proceeded through the initial mechanism of physical adsorption. Deviation of the adsorption of the gum from the ideal Langmuir adsorption isotherm and the nature of adsorption were accounted for by Frumkin, El Awardy and Dubinin-Radushkevich (D-RIM) adsorption isotherms. The study provides information on the physicochemical constituents of t...

International Journal of Electrochemical Science, 2012

Chemical constituents of purified sample of Ficus platyphylla gum was investigated using GCMS tec... more Chemical constituents of purified sample of Ficus platyphylla gum was investigated using GCMS technique. The results obtained indicated the presence of methoxy-phenyl-oxime (0.79 %), 1

This study was carried out to determine the effect of lecture and demonstration methods on academ... more This study was carried out to determine the effect of lecture and demonstration methods on academic achievement of students in Chemistry in the Nassarawa Local Government Area of Kano State. Fifty eight (58) Chemistry students (boys and girls) in the Senior Secondary School One (SS1) from two randomly selected schools were involved in the study. Necessary data were collected and the validated reliable data were analyzed using t-test at a significant level of 0.05. Results obtained revealed that students perform better in Chemistry when taught using the demonstration method as compared to the lecture method. The boys and girls are better in academic achievement when taught using demonstration method than when lecture method was used. The demonstration method shows equality in the performance of boys and girls. Hence the adoption of demonstration methods in the teaching and learning of Chemistry and science in general is hereby recommended.

Batch adsorption studies were used to evaluate the adsorption capacity of Iraqi Palm Date in the ... more Batch adsorption studies were used to evaluate the adsorption capacity of Iraqi Palm Date in the removal of Cd(II) and Cu(II) ions from synthetic aqueous solutions was evaluated. The effects of adsorbent loads, contact time, initial metal concentration, pH and temperature have also been reported. The applicability of Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R) isotherm was tried for the system to completely understand the adsorption isotherm processes. The data fitted pseudo-second-order kinetic model with high correlation indicating that the adsorption processes were chemisorptions. The present data confirms that Iraqi Palm Date may be used as efficient adsorbent for the removal of cadmium (II) and copper (II) ions from aqueous solution.

The corrosion inhibition of zinc in 1.0 M H2SO4 solution by Cefuroxime axetil has been studied in... more The corrosion inhibition of zinc in 1.0 M H2SO4 solution by Cefuroxime axetil has been studied in relation to the concentration of the additive using weight loss measurement, Linear polarization resistant (LPR) and potentiodynamic polarization (PDP).The results indicate that Cefuroxime axetil inhibited corrosion reaction in the acid medium and inhibition efficiency increased with inhibitor concentration. The inhibitor was found to be adsorption inhibitor that best fitted the Langmuir adsorption model. From calculated values of activation energy, free energy of adsorption and the variation of inhibition efficiency with temperature, it was deduced that the adsorption of the inhibitor favours the mechanism of physical adsorption. The polarization data indicate that the inhibitor was of mixed type. The results obtained from LPR, PDP and weight loss measurements were in good agreement.

Hair samples collected from thirty-four (34) individuals in Wudil Local Government Area of Kano S... more Hair samples collected from thirty-four (34) individuals in Wudil Local Government Area of Kano State Nigeria with respected to age, sex and smoking habits were analyzed for trace metals (Ca, Zn, Cu, Cd, Cr, Mg and Pb) using Atomic Absorption Spectrophotometric (AAS) technique. The result obtained indicated the mean concentrations of trace metals in the human hair of both male and female respondent follow similar trend as Ca>Zn>Cu>Pb>Cr>Mg>Cd. The levels of Ca and Mg were found higher in female respondents compared to the men. Also, the standard deviation obtained for the level of Pb and Cd were higher in males while Cr was found to be higher in females. Cd and Ca shows a gradual increase as it rises thorough the studied age groups, and the abruptly drops at the last age group (≥ 41). Cu was also found to have the highest concentration in individuals of the highest age group (≥ 41). Age and smoking habits also had great influence on trace metal hair concentrations ...

Walailak Journal of Science and Technology, Jan 4, 2013

GCMS (Gas Chromatography Mass Spectrometry), FTIR (Fourier Transformed Infra-Red Spectroscopy), S... more GCMS (Gas Chromatography Mass Spectrometry), FTIR (Fourier Transformed Infra-Red Spectroscopy), SEM (Scanning Electron Microscopy), physiochemical and rheological analysis of Albizia zygia gum have been carried out. Albizia zygia exudate is a brownish in colour, acidic and ionic gum. GCMS spectra of the gum indicated the presence of (E)-methyl octadec-7-enoate (41.18 %), methyl palmitate (18.64 %), methyl stearate (19.13 %), (9E,12E)-methyl octadeca-9,12-dienoate (11.88 %), methyl icosanoate (1.85 %), 2,3-dihydroxypropyl oleate (2.05 %), (Z)-octadec-13-enal (1.63 %), 2hydroxy-3-(palmitoyloxy)propyl stearate (1.55 %), 2,3-dihydroxypropyl stearate (0.82 %), dimethyl phthalate (0.58 %) and 3-((aminomethoxy) (hydroxy)phosphoryloxy)propane-1,2-diyl dipalmitate (0.70 %). The FTIR spectrum of the gum indicated several functional groups, including-OH, CO and C=O. From the scanning electron micrograph, the morphology of the gum shows irregular shapes embedded on the surface. Rheological studies indicated that the viscosity of the gum increased with increasing pH but decreased with an increase in temperature. Application of Huggins, Kraemer and Tanglertpaibul and Rao models indicated that the intrinsic viscosity of the gum is in the range of 0.5-0.8. Plots obtained for the variation of viscosity with shear rate and shear rate with shear stress confirmed that Albizia zygia gum is a non Newtonian dilatant polymer with a characteristic shear thickening property.

International Journal of Metals, 2015

A comparative study of the inhibitory potentials of gum exudates from Albizia ferruginea (AF) and... more A comparative study of the inhibitory potentials of gum exudates from Albizia ferruginea (AF) and Khaya senegalensis (KS) on the corrosion of mild steel in HCl medium was investigated using weight loss and gasometric method. The active chemical constituents of the gum were elucidated using GC-MS while FTIR was used to identify the bonds/functional groups in the gums. The two gum exudates were found to be good corrosion inhibitors for mild steel in acidic medium. On comparison, maximum inhibition efficiency was found in Khaya senegalensis with 82.56% inhibition efficiency at 0.5% g/L concentration of the gum. This may be due to the fact that more compounds with heteroatoms were identified in the GCMS spectrum of KS gum compared to the AF gum. The presence of such compounds may have enhanced their adsorption on the metal surface and thereby blocking the surface and protecting the metal from corrosion. The adsorption of the inhibitors was found to be exothermic and spontaneous and fitt...

International Journal of Physical Sciences, Apr 30, 2014

Gas chromatographic-mass spectrometry (GCMS), fourier transformed infra-red spectroscopy (FTIR) a... more Gas chromatographic-mass spectrometry (GCMS), fourier transformed infra-red spectroscopy (FTIR) and physicochemical analysis of Commiphora kestingii gum have been carried out. The corrosion inhibition characteristics of C. kestingii (CK) gum on aluminium in sulphuric acid media were also investigated at 303 and 333K using gravimetric and scanning electron microscopic studies (SEM) method. The study revealed that the gum contains significant amount of Sucrose, Octadecanoic acid, Alpha camphorenal, Nerolidolisobutyrate, Diisopropenyl-1-methyl-1-vinyl cyclohexane, Abetic acid, Oleic acid, Verbenol, 2,6-dimethylhepta-1,5-diene, Naphthalene, Limonene, 7-hexadecenal and 10methyl-8-tetradecen-1-ol acetate. Corrosion inhibition tests suggest that GS gum is a good inhibitor for the corrosion of Al in solution of H 2 SO 4. The inhibition efficiency of this inhibitor increased with increasing temperature suggesting chemisorption mechanism. Also, the inhibition efficiency of these extract was found to increase in the presence of CK. Inhibition of Aluminium by C. kestingii gum occurred through synergistic adsorption of the various components of the gums hence the formation of multiple adsorption layer is proposed.

The inhibitive effect of Khaya ivorensis gum exudate (KI) for the corrosion of mild steel in HCl ... more The inhibitive effect of Khaya ivorensis gum exudate (KI) for the corrosion of mild steel in HCl medium has been evaluated using the weight loss, gasometric, and thermometric techniques. The inhibition efficiencies of the gum were found to increase with increasing concentration of inhibitors and decreased with increase in temperature, indicating that KI gum is a good adsorption inhibitor for the corrosion of mild steel in solution of HCl. The adsorption of inhibitor on mild steel surface is first order, exothermic, spontaneous and the adsorption characteristic of the studied inhibitor was best described by the Langmuir adsorption isotherm. Phenomenon of physical adsorption is proposed from the values of kinetic and thermodynamic parameters obtained.

Abstract:Studies on the corrosion inhibition potentials of ciprofloxacin were carried out using g... more Abstract:Studies on the corrosion inhibition potentials of ciprofloxacin were carried out using gravimetric, thermometric and scanning electron microscopy techniques. The inhibition efficiencies of ciprofloxacin for the corrosion of mild steel increased with increase in concentration but decreased with rise in temperature. The scanning electron microscopy shows that the damaging effect of the acid on the metal surface is greatly reduced with the presence of the inhibitor. This may probably be due to the formation of protective coverage by the inhibitor. Adsorption characteristics of the inhibitor has also been studied and it is found that ciprofloxacin inhibits the corrosion of mild steel by being adsorbed on the surface of mild steel by a physicaladsorption mechanism. The adsorption of ciprofloxacin on the mild steel surface was found to be spontaneous and obey the Langmuir adsorption isotherm model. Keywords:corrosion; mild steel; inhibitor; adsorption; ciprofloxacin.

Chemical Engineering Communications, 2014

ABSTRACT Physico-chemical constituents of GLORIOSA SUPERBA gum exudate were analyzed using recomm... more ABSTRACT Physico-chemical constituents of GLORIOSA SUPERBA gum exudate were analyzed using recommended chemical methods. Results obtained from FT-IR study indicated the presence of functional groups that are typical for polysaccharides. Gas chromatography-mass spectrometry spectrum of the gum revealed the presence of 1-piperoylp, 1-penta-decarboxylic acid, 9-octadecenoic acid, and stigmasta-5,22-dien-3-ol. Based on its chemical constituents, corrosion inhibition potentials of various concentrations of the gum were investigated using FT-IR and gravimetric methods. The results obtained showed that GLORIOSA SUPERBA gum is an inhibitor for the corrosion of Al in solution of HCl. The initial mechanism for the inhibition of Al corrosion by GLORIOSA SUPERBA gum was found to be physiosorption and was succeeded by chemisorption. Although the Langmuir adsorption model supported the adsorption characteristics of the gum, the existence of interaction between the inhibitor particles was confirmed by the fitness of Flory-Huggins, Parsons, and Volmer adsorption isotherms. Analysis of El-Awady et al. kinetic isotherm revealed the formation of multiple layers of inhibitor on the surface of Al. The adsorption strength of the inhibitor was also found to increase with increasing temperature. Data obtained from the application of the Gibb-Helmholtz equation and Bockris-Swinkle adsorption model reflected spontaneous adsorption of the gum on the Al surface through chemisorption. From quantum chemical studies, it was found that the adsorption of the gum on the Al surface is facilitated by the presence of amide and hydroxyl functional groups in stigmasta-5,22-dien-3-ol and 1-piperoylp respectively.

Asian Journal of Chemistry, 2013

Physicochemical studies on Anogeissus leiocarpus gum (AL gum) indicated that the gum is mildly ac... more Physicochemical studies on Anogeissus leiocarpus gum (AL gum) indicated that the gum is mildly acidic, ionic, odourless, yellowish-red and is soluble in water (but insoluble in ethanol, acetone and chloroform). The gum has significant concentration of essential elements (Mg, Ca, Fe, Cu, Mn) and low concentrations of heavy metals (Pb and Cd). The protein content of the sample was also found to be low (≈5 %). Scanning electron micrograph of the gum revealed that the gum is irregularly shaped and amorphous. Rheological study indicated that the viscosity of the gum increases with increasing pH and concentration but decreases with increase in temperature. The apparent activation energy of flow for Anogeissus leiocarpus gum (calculated fromArrhenius-Frenkel-Eyring plot) was 3.16 suggesting the presence of fewer inter and intra molecular interaction. Values of intrinsic viscosity obtained from Huggins and Kraemer plots were similar (8.82) while those obtained from Tanglertpaibul and Roa plots ranged from 3.50 to 11.82 dL/g. From the plot of speed of rotation versus viscosity, viscosity versus shear rate and shear stress versus shear rate, a non Newtonian behaviour (dilatant) with characteristics shear thickening property was verified for Anogeissus leiocarpus gum. Calculated ‘b’ value of 1.108 was obtained through the application of the power law equation and is associated with random coil conformation or entanglement. Analysis of the master's curve shows that random coil conformation or entanglement is proposed to occur at C[η]~ 4.0, i.e. at ηsp = 2.19 (ηrel = 3.19).

The adsorption of Cd(II) and Cr(VI) ions from synthetic solutions was performed using activated l... more The adsorption of Cd(II) and Cr(VI) ions from synthetic solutions was performed using activated locust bean husk (ALBH). The adsorption depends on temperature, pH of the solution, type of ions, initial concentration of metals and the adsorbent concentration. The equilibrium data were analyzed using Langmuir and Freundlich isotherm models. The maximum adsorption capacity of the adsorbent was in the range of 3.17 mg/g for Cd(II) and 4.13 mg/g for Cr(VI). The experimental results demonstrated that ALBH could be used for the removal of Cd(II) and Cr(VI) ions from aqueous medium through adsorption.

Examination of the physical (colour, odour, pH, solubility in various solvents) and chemical (GCM... more Examination of the physical (colour, odour, pH, solubility in various solvents) and chemical (GCMS and FTIR) characteristics of Ficus benjamina gum revealed that the gum is yellowish in colour, mildly acidic and ionic in nature. Major constituents of the gums were found to be sucrose and d-glucose, which constituted 60.92 % of their chemical constituents, while various carboxylic acids [(albietic acid (1.00%), hexadecanoic acid (4.41 %), 9-octadecanoic acid (1.00 %), octadecanoic acid (3.01 %), oleic acid (0.10 %), octadecanoic acid (9.12 %) and 6,13-pentacenequinone (20.43 %)] accounted for the remaining constituents. Functional groups identified in the gum were found to be those typical for other carbohydrates. From the knowledge of the chemical structures of compounds that constitute the gum, the corrosion inhibition potentials of the gum were ascertained and from weight loss analysis, the gum was found to be an active inhibitor against the corrosion of aluminum in solutions of t...

Ficus platyphylla gum exudates (FP gum) have been analyzed for their physicochemical parameters a... more Ficus platyphylla gum exudates (FP gum) have been analyzed for their physicochemical parameters and found to be ionic, mildly acidic, odourless, and yellowish brown in colour. e gum is soluble in water, sparingly soluble in ethanol, and insoluble in acetone and chloroform. e nitrogen (0.39%) and protein (2.44%) contents of the gum are relatively low. e concentrations of the cations were found to increase according to the following trend, Mn>Fe>Zn>Pb>Cu>Mg>Cd>Ca. Analysis of the FTIR spectrum of the gum revealed vibrations similar to those found in polysaccharides while the scanning electron micrograph indicated that the gum has irregular molecular shapes, arranged randomly. e intrinsic viscosity of FP gum estimated by extrapolating to zero concentrations in Huggins, Kraemer, Schulz-Blaschke, and Martin plots has an average value of 7 dL/g. From the plots of viscosity versus shear rate/speed of rotation and also that of shear stress versus shear rate, FP gum ...

The adsorption of Cd(II) and Cr(VI) ions from synthetic solutions was performed using activated l... more The adsorption of Cd(II) and Cr(VI) ions from synthetic solutions was performed using activated locust bean husk (ALBH). The adsorption depends on temperature, pH of the solution, type of ions, initial concentration of metals and the adsorbent concentration. The equilibrium data were analyzed using Langmuir and Freundlich isotherm models. The maximum adsorption capacity of the adsorbent was in the range of 3.17 mg/g for Cd(II) and 4.13 mg/g for Cr(VI). The experimental results demonstrated that ALBH could be used for the removal of Cd(II) and Cr(VI) ions from aqueous medium through adsorption.

Examination of the physical (colour, odour, pH, solubility in various solvents) and chemical (GCM... more Examination of the physical (colour, odour, pH, solubility in various solvents) and chemical (GCMS and FTIR) characteristics of Ficus benjamina gum revealed that the gum is yellowish in colour, mildly acidic and ionic in nature. Major constituents of the gums were found to be sucrose and d-glucose, which constituted 60.92 % of their chemical constituents, while various carboxylic acids [(albietic acid (1.00%), hexadecanoic acid (4.41 %), 9-octadecanoic acid (1.00 %), octadecanoic acid (3.01 %), oleic acid (0.10 %), octadecanoic acid (9.12 %) and 6,13-pentacenequinone (20.43 %)] accounted for the remaining constituents. Functional groups identified in the gum were found to be those typical for other carbohydrates. From the knowledge of the chemical structures of compounds that constitute the gum, the corrosion inhibition potentials of the gum were ascertained and from weight loss analysis, the gum was found to be an active inhibitor against the corrosion of aluminum in solutions of t...

International Journal of Electrochemical Science, 2011

GCMS study of Anogessus leocarpus gum (AL gum) indicated the presence of sucrose (10.03 %), phtha... more GCMS study of Anogessus leocarpus gum (AL gum) indicated the presence of sucrose (10.03 %), phthalic acid (2.53 %), n-hexadecanoic acid (11.73 %), oleic acid (30.49 %), pentacenequinone (4.41 %) and 2,3-diphenylnaphthoquinone (21.43 %). The gum was found to be a good adsorption inhibitor for the corrosion of mild steel in HCl solution. The adsorption of the inhibitor on mild steel surface is exothermic, spontaneous, Langmuir type and supports the mechanism of charged transfer from the inhibitor's molecule to the charged metal surface. FTIR study of the AL gum and the corrosion product of mild steel (in the presence of AL gum as an inhibitor) indicated the presence of interaction between the inhibitor and the metal surface (some shifts in frequencies of IR adsorption), some functional groups were used for the adsorption of the inhibitor onto the metal surface (missing functional groups) and others for the formation of Fe-inhibitor complex (new functional groups formed). The inhibition of mild steel corrosion is proposed to occur through synergistic combination of the constituents of the inhibitor, which facilitates the formation of multi-molecular layer of adsorption and the formation of inhibitor-metal complex, which protected the metal from further corrosion attack.