Theoretical study of 3-(4-hydroxyphenyl)-1-(4-nitrophenyl) prop-2-en-1-one and 3-(4-hydroxyphenyl)-1-phenylprop-2-en-1-one as corrosion inhibitors on mild steel

Corrosion inhibition efficiency of 3-(4-hydroxyphenyl)-1-(4-nitrophenyl) prop-2-en-1-one and 3-(4-hydroxyphenyl)-1-phenylprop-2-en-1-one on mild steel was studied through the evaluation of their quantum chemical parameters and simulation molecular dynamics methods. Quantum chemical calculations were used to provide molecular explanations for the inhibitive effects of the inhibitor molecules. Results revealed that the parameters associated with the electronic structures of the inhibitor molecules confirmed their inhibitory potential through highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), energy gap (ΔE), dipole moment, electronegativity (χ), global hardness (ղ) and fraction of electron transfer (ΔN) from the inhibitor molecule to the iron metallic atom. In addition, the local reactivity has been analyzed through the Fukui function and condensed softness indices and has been found to be located on the molecule’s heteroatoms (oxygen and nitrogen). The molecular dynamic simulation result showed that the adsorption energy is low, negative and within the threshold of physical adsorption mechanism

2,3-bis-phenylamino-but-2-enedioc acid diethyl ester as a corrosion inhibitor on mild steel, Aluminum, and zinc surface. a computational study

AbstractZinc Aluminum and Mild steel are some of the metallic materials highly used in construction of different materials of economic importance, though susceptible to corrosion at different environment exposed. Control of this corrosion inhibition is done through the help of some inhibitors. This study used density functional theory DFT parameters and molecular dynamic simulation energy parameters to study the mechanism of the corrosion inhibition of 2,3-bis-phenylamino-but-2-enedioc acid diethyl ester on Zn (110), Fe (111) and Al (110). The low adsorption/binding energy values for Zn and Al indicated mild inhibition and Physisorption. While the adsorption value obtained by Fe surface indicated mild steel mechanism was chemical. From the bond angle calculation, the molecule is expected to have exhibited sp2 hybridization with much of p-orbital on the metal surface hence the calculated bond angles for the inhibitor molecule for both surfaces is trigonal planer (±180 or ±0°) 

COMPUTATIONAL STUDY OF THE CHEMICAL REACTIVITY PROPERTIES OF GLYCOSYDATED SECO-IRIDOID COMPOUND AS CORROSION INHIBITOR, ON MILD STEEL AND ALUMINUM METAL

In this research, the compound was studied theoretically using computational methods to give further analysis on the inhibition of oleuropein on mild steel and Aluminium. Parameters were studied using quantum chemical method through DFT and molecular dynamic simulations. Mild steel Fe (111) and Al (110) surfaces was used due to their respective close packed and densely atom. Fukui function, the local and global reactivity were calculated to give the reactivity of the molecule. Based on the values of calculated adsorption and binding energies (-70.287, 70.287 Kcal/mol) and (-113.193, 113.193 Kcal/mol) obtained on both surfaces, the mechanism of oleuropein is inferred to exhibit physiosorption on Aluminium surface and Chemisorption on mild steel surface

Paraquat dichloride adsorption from aqueous solution using Carbonized Bambara Groundnut (Vigna subterranean) Shells

Carbonized Bambara GroundNut Shell (CBGNS) was used as adsorbent for the adsorption of paraquat dichloride (PQ) from aqueous solution. The prepared adsorbent was characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy methods. Several parameters that might affect the adsorption process including pH, contact time, adsorbent dosage, temperature and initial concentration were investigated and optimized using batch adsorption technique. Results of the study revealed that maximum removal efficiency (98%) was achieved using 0.05g adsorbent dosage, solution pH of 5 and 60 min of contact time. The equilibrium experimental result revealed that Langmuir model best described the adsorption process with R2 value of 0.956.The heat of adsorption process was estimated from Temkin Isotherm model to be 19.99J/mol and the mean free energy was estimated from Duninin-Radushkevich (DRK) isotherm model to be 0.289KJ/mol indicating chemisorptions process. The kinetic and thermodynamic studies revealed that the adsorption processes followed pseudo-second-order kinetics with R2 value of 0.999 and the value of ∆G (- 27.74 kJ mol-1), ∆H (13.145 kJ mol-1) indicate the spontaneous and endothermic nature of PQ adsorption on CBGNS. The results suggested that CBGNS had the potential to become a promising material for PQ contaminated water treatment. Keywords: Adsorption, Paraquat dichloride, Carbonized Bambara Ground nut shell, Water treatment

Quantum Chemical Studies and Molecular Modeling of the Effect of Coriandrum Sativum L. Compounds as Corrosion Inhibitors on Aluminum Surface

Corrosion inhibition activity of Coriandrum sativum L. compounds namely: terpinen-4-ol, anethole and limonene on aluminium (110) surface was investigated by quantum chemical parameters calculation and molecular dynamics simulation. Quantum chemical parameters such as EHOMO (Highest occupied molecular orbital energy), ELUMO (Lowest unoccupied molecular orbital energy), energy gap (ΔE), dipole moment (μ), global hardness (η), global softness (σ), the absolute electronegativity (χ) and the fractions of electrons transferred (ΔN) from the Coriandrum sativum L. molecules to aluminum surface were studied to investigated their relative corrosion inhibition performances.  The local reactive sites parameters of the studied molecules has been analyzed through fukui functions and condensed softness indices. Furthermore, adsorption energies of the inhibitor molecules on Al (110) surface were analyzed using molecular dynamic simulation. The binding strength of inhibitor molecules on the aluminium metal surface follow the order terpinen-4-ol > limonene>anethole. In view of the above, our approach will be helpful for easy Quantum chemical calculations and Molecular dynamics simulation prediction for a potential inhibitor from a variety of similar inhibitors and subsequently in their rational designed synthesis for corrosion inhibition application following a wet chemical synthetic route

Density functional theory and molecular dynamic simulation studies on the corrosion inhibition of some thiosemicarbazide derivatives on aluminum metal

Aluminum (Al), one of the most comercially used metals is also susceptible to corrosion like iron and zinc when subjected to corrosive environments, either in the industries or during applications in general. One major method of controlling corrosion of Al is through the use of inhibitors which are usually compounds containing heteroatoms, conjugated systems or which are relatively large in size. One of such inhibitors, thiosemicarbazide derivatives were reported in literature as an Al inhibitor in 2M HCl solution through experimental studies. In this study, computational methods were used to further provide an indepth explanation into the mode and mechanism of the thiosemicarbazides inhibition on Al surface. Parameters including quantum chemical through DFT and molecular dynamic simulations of studied molecules on Al surfaces were conducted. Results obtained through calculation of adsorption or binding energies of these thiosemicarbazides were in good agreement with the experimentally reported results elsewhere. With respect to the calculated adsorption or binding energies, thier relatively low values infered that the compounds are weakly adsorbed onto the surface of Al through Van der Waals forces and therefore obey the mechanism of physical adsorption. It was also established that the reference molecule thiosemicarbazide (TSC) was least adsorbed when compared to the other five molecules of its derivatives. The order of the inhibition efficiency as determined is as follows: PBT>DTC>DPT>PCT>PTC>TS

The Adsorptive properties of 4-Hexyl-tertrahydro-thiopyran-1,1-diode on Al(110) and Fe(111) surface using DFT method

Aluminum and iron are highly significant industrial commodities that are used to make anything from tools and concrete construction to roofing sheets and other roofing-related products. Even though they generate a protective oxygen barrier that prevents corrosion, they are nevertheless susceptible to corrosion in extreme conditions. In order to achieve the stable shape of the molecule HTTD, a theoretical investigation on the corrosion inhibition of metals like Aluminum and iron was conducted utilizing local density function B3LYP under limited spin polarization DNP foundation. The values of local/global reactivity parameters, including the (ω+) electroaccepting power and (ω-) electrodonating power between the inhibitor molecule and the metal surfaces, were demonstrated. These parameters included EHOMO, ELUMO, energy gap (∆Eg), electronegativity (χ), global hardness (η), global electrophilicity index (ω), and fraction of electron transfer (∆N). Physisorption mode was defined as the mode of interaction of HTTD on Aluminium and Chemical Adsorption on Iron surface based on the simulation modeling output. The outcome of Fukui functions revealed that the focus point for the selectivity of electron donation and acceptance between the metal and the moiety is a hetero-atom present in the molecule such as oxygen, sulfur and the methylene (-CH2-) functional group