Howida Mandour - Academia.edu (original) (raw)
Papers by Howida Mandour
BMC chemistry, Jul 2, 2024
Portugaliae Electrochimica Acta, 2021
Environmental green compounds have emerged as powerful inhibitors for metals and alloys corrosion... more Environmental green compounds have emerged as powerful inhibitors for metals and alloys corrosion. So, this article attempts to show that barbituric (BA) and thiobarbituric acids (TBA) are good green corrosion inhibitors for copper immersed in 0.6 mol/L NaCl. A combination of quantitative and qualitative tools were used in this investigation, such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, FT-IR spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Polarization measurements indicate that these compounds can function as mixed type inhibitors. It was found that the adsorption of these inhibitors onto the copper surface obeyed Flory-Huggins isotherm. Also, the effect of temperature in the inhibitors absence and presence was studied according to Arrhenius isotherm. Some thermodynamic functions of dissolution and adsorption processes were calculated, such as activation energy (Ea), enthalpy (ΔH *), free energy (ΔG o) and entropy (ΔS *). The barbituric and thiobarbituric acids recorded high inhibition efficiency of copper corrosion at concentrations of 5x10-3 mol/L and 1x10-3 mol/L, respectively.
Journal of Molecular Structure, 2021
Current Nanoscience, 2020
Background:Increasing the bioactivity of metallic implants is necessary for biomaterial applicati... more Background:Increasing the bioactivity of metallic implants is necessary for biomaterial applications where hydroxyapatite (HA) is used as a surface coating. In industry, HA is currently coated by plasma spraying, but this technique has a high cost and produces coating with short-term stability.Objectives:In the present study, electrophoretic deposition (EPD) was used to deposit nano-biphasic calcium phosphate compound (β-tri-calcium phosphate (β-TCP) /hydroxyapatite (HA)) bio-ceramics on the titanium surface. The microstructural, chemical compositions and bioactivity of the β- TCP/HA coatings were studied in a simulated body fluid solution (SBF).Methods:Scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FTIR) were used. Additionally, the antibacterial effect was studied by the agar diffusion method. The corrosion behavior of the β-TCP/HA coating on titanium surface (Ti) in the SBF solution at 37oC ...
Journal of Physical Organic Chemistry, 2019
A series of Cu (II), Mn (II), Co (II), Zn (II), Cr (III), and VO (IV) complexes with N‐(4‐(2‐hydr... more A series of Cu (II), Mn (II), Co (II), Zn (II), Cr (III), and VO (IV) complexes with N‐(4‐(2‐hydrazinyl‐2‐oxoethoxy)phenyl) acetamide (HL) were synthesized. The electrical properties of HL and its Cu (II), Co (II), Zn (II), and Cr (III) complexes were measured in the 298 to 373 K temperature range. The activation energy of each of these metal complexes was estimated. The conductivities of the metal complexes with HL increase with increasing temperature, revealing their semiconducting nature and potential for use in electronic devices. The complexes exhibited higher conductivities than HL itself. The kinetic parameters of these complexes, such as their stability constants (Kc values) and Gibbs free energies (∆G°), were investigated by using cyclic voltammetry. These parameters indicated that the prepared compounds exhibited better stability and adsorption properties than paracetamol (PA), which is the parent compound of these species. The complexes were more cytotoxic than the ligand...
New Journal of Chemistry, 2018
Novel organic nanoparticles were successfully prepared using the re-precipitation method and show... more Novel organic nanoparticles were successfully prepared using the re-precipitation method and showed superior protection against mild steel corrosion in acidic media.
![Research paper thumbnail of The Inhibiting Effect of Non Toxic 4-Amino antipyrine and 4,6-Dimethyl-1H-pyrazolo[3,4-b]pyridin-3-amine on Mild steel Corrosion in Sulphuric acid](https://attachments.academia-assets.com/119420954/thumbnails/1.jpg)
](International Journal of Electrochemical Science, 2016
Potentiodynamic polarization, electrochemical impedance, weight loss, and scanning electron micro... more Potentiodynamic polarization, electrochemical impedance, weight loss, and scanning electron microscopy (SEM) techniques are used to study the inhibiting effect of 4-amino antipyrine (AAP) and the prepared 4,6-dimethyl-1H-pyrazolo[3,4-b]pyridin-3-amine (PP) in order to decrease the dissolution of mild steel in 0.5 M H 2 SO 4 .The results indicate that increasing inhibitors concentration increases the efficiency of inhibition and increasing the temperature decreases the efficiency of inhibition. The AAP compound was seen to retard the rate of corrosion of mild steel more effective than PP compound. The adsorption of the AAP inhibitor on the mild steel surfaces obeys both of Langmuir and Temkin isotherms while PP inhibitor obeys only Langmuir isotherm. Studies of the scanning electron microscopy established the corrosion protection property of AAP and PP to be through adsorption on sites on the mild steel surface which are active. Also, mixed action of the inhibitors effect is showed from the results. The theoretical assumptions show proper agreement with most of experimental data. Temperature studies are occurred to find the thermodynamic parameters of inhibition and to suggest the isotherm of the adsorption processes.
Surfaces and Interfaces, 2016
Journal of Molecular Structure, 2021
BMC chemistry, Jul 2, 2024
Portugaliae Electrochimica Acta, 2021
Environmental green compounds have emerged as powerful inhibitors for metals and alloys corrosion... more Environmental green compounds have emerged as powerful inhibitors for metals and alloys corrosion. So, this article attempts to show that barbituric (BA) and thiobarbituric acids (TBA) are good green corrosion inhibitors for copper immersed in 0.6 mol/L NaCl. A combination of quantitative and qualitative tools were used in this investigation, such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, FT-IR spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Polarization measurements indicate that these compounds can function as mixed type inhibitors. It was found that the adsorption of these inhibitors onto the copper surface obeyed Flory-Huggins isotherm. Also, the effect of temperature in the inhibitors absence and presence was studied according to Arrhenius isotherm. Some thermodynamic functions of dissolution and adsorption processes were calculated, such as activation energy (Ea), enthalpy (ΔH *), free energy (ΔG o) and entropy (ΔS *). The barbituric and thiobarbituric acids recorded high inhibition efficiency of copper corrosion at concentrations of 5x10-3 mol/L and 1x10-3 mol/L, respectively.
Journal of Molecular Structure, 2021
Current Nanoscience, 2020
Background:Increasing the bioactivity of metallic implants is necessary for biomaterial applicati... more Background:Increasing the bioactivity of metallic implants is necessary for biomaterial applications where hydroxyapatite (HA) is used as a surface coating. In industry, HA is currently coated by plasma spraying, but this technique has a high cost and produces coating with short-term stability.Objectives:In the present study, electrophoretic deposition (EPD) was used to deposit nano-biphasic calcium phosphate compound (β-tri-calcium phosphate (β-TCP) /hydroxyapatite (HA)) bio-ceramics on the titanium surface. The microstructural, chemical compositions and bioactivity of the β- TCP/HA coatings were studied in a simulated body fluid solution (SBF).Methods:Scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FTIR) were used. Additionally, the antibacterial effect was studied by the agar diffusion method. The corrosion behavior of the β-TCP/HA coating on titanium surface (Ti) in the SBF solution at 37oC ...
Journal of Physical Organic Chemistry, 2019
A series of Cu (II), Mn (II), Co (II), Zn (II), Cr (III), and VO (IV) complexes with N‐(4‐(2‐hydr... more A series of Cu (II), Mn (II), Co (II), Zn (II), Cr (III), and VO (IV) complexes with N‐(4‐(2‐hydrazinyl‐2‐oxoethoxy)phenyl) acetamide (HL) were synthesized. The electrical properties of HL and its Cu (II), Co (II), Zn (II), and Cr (III) complexes were measured in the 298 to 373 K temperature range. The activation energy of each of these metal complexes was estimated. The conductivities of the metal complexes with HL increase with increasing temperature, revealing their semiconducting nature and potential for use in electronic devices. The complexes exhibited higher conductivities than HL itself. The kinetic parameters of these complexes, such as their stability constants (Kc values) and Gibbs free energies (∆G°), were investigated by using cyclic voltammetry. These parameters indicated that the prepared compounds exhibited better stability and adsorption properties than paracetamol (PA), which is the parent compound of these species. The complexes were more cytotoxic than the ligand...
New Journal of Chemistry, 2018
Novel organic nanoparticles were successfully prepared using the re-precipitation method and show... more Novel organic nanoparticles were successfully prepared using the re-precipitation method and showed superior protection against mild steel corrosion in acidic media.
International Journal of Electrochemical Science, 2016
Potentiodynamic polarization, electrochemical impedance, weight loss, and scanning electron micro... more Potentiodynamic polarization, electrochemical impedance, weight loss, and scanning electron microscopy (SEM) techniques are used to study the inhibiting effect of 4-amino antipyrine (AAP) and the prepared 4,6-dimethyl-1H-pyrazolo[3,4-b]pyridin-3-amine (PP) in order to decrease the dissolution of mild steel in 0.5 M H 2 SO 4 .The results indicate that increasing inhibitors concentration increases the efficiency of inhibition and increasing the temperature decreases the efficiency of inhibition. The AAP compound was seen to retard the rate of corrosion of mild steel more effective than PP compound. The adsorption of the AAP inhibitor on the mild steel surfaces obeys both of Langmuir and Temkin isotherms while PP inhibitor obeys only Langmuir isotherm. Studies of the scanning electron microscopy established the corrosion protection property of AAP and PP to be through adsorption on sites on the mild steel surface which are active. Also, mixed action of the inhibitors effect is showed from the results. The theoretical assumptions show proper agreement with most of experimental data. Temperature studies are occurred to find the thermodynamic parameters of inhibition and to suggest the isotherm of the adsorption processes.
Surfaces and Interfaces, 2016
Journal of Molecular Structure, 2021