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The inhibitory impacts of two expired drugs, namely, azithromycin (AZM) and roxithromycin (RXM) towards the corrosion of mild steel (MS) in 1.0 M H2SO4 solution were examined exploiting potentiodynamic polarization, electrochemical impedance spectroscopy and weight loss techniques. The results obtained from various employed techniques indicate that increasing the concentration of examined expired drugs and reducing the temperature increased the inhibition efficiencies. Potentiodynamic polarization indicated that the expired AZM and RXM drugs acted as mixed-type inhibitors, but the cathode was highly polarized, βc > βa. The inhibiting power of these compounds is interpreted based on their adsorption on the surface of MS. The adsorption process obeys Langmuir isotherm. Impedance data confirmed that MS corrosion is under charge transfer control and the adsorption of both expired drugs on the MS surface led to the formation of protective film. The inhibition efficiency of RXM is greater than that of AZM due to the increased molecular weight and number of electron donating group within the expired drug. Activation and adsorption thermodynamics parameters were computed and interpreted. The adsorption process is spontaneous and endothermic.

The inhibition impacts of two novel synthesized green biosurfactants (B-Surf.), namely, sodium N-dodecyl asparagine (AsS) and sodium N-dodecyl arginine (ArS), on the dissolution of mild steel alloy (MS-37-2), in aqueous sodium chloride solutions was inspected using various techniques. Increased concentration of NaCl solution resulted in an increase in the corrosion rate of MS-37-2. Inhibition efficiencies of B-Surf. compounds were found to increased with increase inhibitor concentrations. The synergistic inhibition action between B-Surf. inhibitors and Zn2+, Al3+ and Ce4+ on the dissolution behavior of steel alloy in NaCl solutions was investigated and interpreted. The surface morphology of the MS-37-2 surface was observed using a scanning electron microscopy (SEM). This adsorption follows Langmuir isotherm. The evaluated thermodynamic functions supported the mechanism of physical adsorption of the inhibitors. The mechanisms of corrosion and its inhibition of MS-37-2 in NaCl solutions were interpreted.

Three nonionic surfactants molecules (NS) derived from a fused pyridine characterized by IR and 1HNMR spectra were synthesized and examined as inhibitors for the corrosion of aluminum (Al) in a solution of HCl (0.5M). Galvanostatic polarization, weight loss and electrochemical impedance measurements were utilized to detect the corrosion parameters. Efficiency of the percentage inhibition increases with increasing concentration of NS molecules and with lowering temperature and surface parameters such as the surface and the interfacial tension. These results led to strong adhesion between the Al surface and NS molecules. NS molecules served as a mixed inhibitor. NS molecules protect the Al from the corrosive attack by its adsorption on its surface according to Langmuir isotherm. The sequence of inhibition efficiency is based on the chemical composition of the examined NS. The activation thermodynamic parameters were determined and interpreted.

The anti-corrosion efficacies of two polymeric molecules, polyvinyl alcohol (PVA) and alginic acid (AA), on the corrosion of SABIC type-X60 carbon steel (CSX60) in 1.0 M HCl solutions were investig...

The anticorrosion potency of Sabic mild steel (MS) in 0.5 M H2SO4 solution was enhanced by three synthetic non-ionic surfactants (NI Surf.) containing pyridine and pyrimidine derivatives. These compounds are safe, environmentally friendly, and harmless to human health. Chemical and electrochemical measurements were used to compute the corrosion parameters. The anticorrosion efficacy increases with increasing the concentration of NI Surf. and with lowering temperature, surface and interfacial tension, and critical micelle concentration. The effectiveness of anticorrosion is interpreted due to the spontaneous horizontal adsorption on the surface of MS by the existence of some active centers that facilitate the adsorption. The adsorption process obeys Temkin isotherm. Potentiodynamic polarization elucidated that the synthetic NI Surf. acted as mixed-type inhibitors. Some surface properties were determined and confirm the anticorrosive effect of these molecules. Quantum chemical parameters as reactivity descriptors were carried out. It should be noted that the results obtained from computational calculations of the specifications are in full agreement with the experimental observations. There is good compatibility between the anticorrosion efficiency obtained from various techniques and surface properties and quantum chemical calculation.

The inhibition potency of expired thiamine or vitamin B1 (VB1) and riboflavin or vitamin B2 (VB2) against SABIC iron corrosion in 0.5 M H2SO4 solutions was investigated using chemical and electrochemical techniques. Theoretical studies such as DFT and MC simulations were performed on both VB1 and VB2 inhibitors to obtain information related to the experimental results. It has been found that the inhibition efficacy assigned from all measurements used increases with increasing concentration of the two expired vitamins and reduces at elevated temperatures. It reached 91.14% and 92.40% at 250 ppm of VB1 and VB2, respectively. The inhibition was explicated by the adsorption of the complex formed between expired vitamins and ferrous ions on the SABIC iron surface. The adsorption was found to obey the Langmuir isotherm model. Galvanostatic polarization demonstrated that the two expired vitamins act as an inhibitor of the mixed type. These expired vitamins have proven effective in inhibiting the pitting corrosion induced by the presence of Cl− ions. The pitting potential is transferred to the positive values showing resistance to pitting damage. The theoretical parameter values are consistent with experimental results.

The effects of two expired antibacterial drugs, amoxicillin (Amo) cefuroxime (Cef), on the corrosion behavior of Sabic iron in 1.0 M HCl solution were examined using weight loss, galvanostatic pola...

Purpose: To investigate the kinetics of oxidative removal of two β-lactam antibiotics (A), namely, ampicillin and flucloxacillin.Methods: In this study, permanganate ion (MnO4-) was used as an oxidant in an alkaline medium at fixed ionic strength of 0.1 mol dm-3 and a temperature of 298 K utilizing a spectrophotometric technique. The obtained oxidation products were characterized using spot tests and FT-IR spectra.Results: The stoichiometry of the reactions was 1:4 (A : MnO4-). The reactions were a first order credence in [MnO4-] and fractional-first order kinetics in antibiotic and hydroxyl ion. Influence of ionic strength was successfully explored. Dependence of reaction rates on temperature was studied and the activation parameters were computed and discussed. A plausible mechanism for the oxidation reactions has been elucidated. A consistent rate-law expression was also derived.Conclusion: This study introduces a significant treatment method for antibiotic removal, thus helping to protect the environment and human health. Keywords: Permanganate, Antibiotics, Oxidative degradation, Kinetics, Mechanism

The corrosion inhibition of aluminum alloy surface (6063AA) by Sildenafil (SIL) in 1 M for both HCl and NaOH solutions was investigated using weight loss, electrochemical techniques and quantum calculations. The inhibitory effect of SIL was explained by the formation of the complex adsorbed on the 6063AA surface. The adsorption obeyed Langmuir isotherm. The adsorption of the SIL is a mix of physical and chemical adsorption, where the free energy of adsorption was found to equal −39.12 and −34.6 KJ/mol, in HCl and NaOH, respectively. Experimental outcomes showed that SIL significantly inhibits the dissolution of 6063Al in both acidic and alkaline media. SIL drug acts as a mixed inhibitor in both two aggressive solutions. The correlation of the inhibition performance of SIL on 6063Al with the molecular structure was adopted using Dmol3 (Materials Studio v7. 0) based on some descriptors as EHOMO and ELUMO. Fukui indices were computed to determine the active sites of the inhibitor molecules. The equilibrium adsorption behavior of SIL on Al (1 1 1) surface was examined using molecular dynamics simulation. The quantum chemical descriptors were found suitable in explaining the inhibitive action of SIL.

The kinetics and mechanistic aspects of the oxidation of two beta-lactam antibiotics (A), ampicillin and flucloxacillin, by alkaline hexacyanoferrate(III) (HCF(III)) were examined using spectrophot...

The inhibiting action of nonionic surfactants, namely, propoxylated fatty esters (PFE) with different number of propylene oxide toward the corrosion of Zn in 0.1 M HCl solutions was investigated. Four techniques were used in this study such as weight loss, galvanostatic polarization, potentiodynamic anodic polarization and electrochemical impedance spectroscopy. The inhibition efficiency of PFE compounds increases by increasing the concentrations of PFE, number of propylene oxide unit and with lowering temperature. The inhibition was interpreted by adsorption of PFE molecules on the Zn surface according Temkin’s isotherm. Galvanstatic polarization indicated that the PFE acts as a mixed type inhibitor. PFE molecules inhibit the pitting corrosion of Zn in a solution containing Cl– ions by moving the pitting potentials into a more noble direction. The activation thermodynamic parameters such as $$E_{{\text{a}}}^{*}$$, ΔH* and ΔS* are calculated and explained.

The polarographic behavior of five Schiff bases compounds (SB) prepared from 2-amino-3-hydroxypyridine was investigated in BR buffer series of pH 2–12. The polarograms of all SB compounds displayed a single irreversible diffusion-controlled 2-electron wave within the whole pH range representing the saturation of the NCH bond. The effect of pH and substituents on electrode reaction have been investigated and discussed. The electrode reaction pathway is found to be H+, e, e, H+ in which the proton uptake precedes the electron transfer. The studied compounds were used as inhibitors for corrosion of carbon steel (CS) in 1 M HCl solution using potentiodynamic polarization technique. The inhibition was explained in view of the adsorption of SP compounds on the CS surface obeying to Freundlich isotherm. These compounds act as good inhibitors as the inhibition efficiency reached 89.5%. The inhibition efficiency of the studied SBs is found to be a function of substituent group. The order of inhibition efficiency follows the sequence: N(CH3) > p-OCH3 > o-OH > H > p-Cl. This order agrees with the sequence of the negative shift in E1/2 values of the SB compounds under investigation. Keywords: Pyridine Schiff bases, Polarography, Corrosion inhibitor, Adsorption

Augmentin is a chemical mixture component medicine (co medicine) known as co-amoxiclav and it is a famous antibiotic used for treatment of a number of bacterial infections, it is so dangerous to be left in the environment after its expired as it is harmful to the child’s, so the present work introduces an idea for using it in the expired form as potential non-toxic (green ) corrosion inhibitor for steel in 1.0 N HCl. Five analytical techniques were used to evaluate the inhibition performance of the expired co-amoiclav drugs namely gravimetric, atomic absorption spectroscopy(AAS), thermometric, gasometric, and acidimetric technique. Effect of expired drug dose, reaction temperature, and pH were studied. The corrosion inhibition was increased with increasing the concentration and decreased with rising the temperature and by lowering the pH values of the medium. The maximum inhibition is (97.8 % at 300 ppm. The used techniques are in good agreement to each other’s (±2 %) indicating the possibility of the using of the expired Augmentin drugs as potential nontoxic green corrosion inhibitor for steel in an industrial field like steel used for application in petroleum industry at lower pH.

The inhibitory effect of tramadol drug (TR) on aluminum (Al) corrosion was demonstrated in 1MHCl solution by weight loss, galvanostatic, potentiodynamic anodic polarization, electrochemical impedance measurements. The inhibition of drug TR is increased with increased concentration and minimize temperature. Data obtained from the polarization mention that TR drug is a mixed inhibitor mainly anodic (βa > βc). The inhibition power of TR drug was explained on the basis of its adsorption on the Al surface and the pitting corrosion of Al is lowered by adding TR drug. Density functional theory (DFT) was utilized to interpret the inhibiting action of TR drug. Some quantum chemical descriptors were carried out. The result of computational calculations of the specifications proves that the address molecule acts as corrosion inhibitors. Keywords: Tramadol drug, Corrosion inhibitors, Adsorption, DFT, Quantum chemical descriptors, Fukui function

The inhibiting action of three derivatives of azole compounds has been investigated for the corrosion of two aluminum-silicon alloys in 0.5 M HCl solution using some electrochemical measurements such as potentiodynamic polarization, electrochemical impedance, and electrochemical frequency modulation. The morphology of the surface was examined by the scanning electron microscopy. It was found that the inhibition efficiency increases with the increase in the concentration of azole compounds. Those compounds acted as mixed inhibitors and their inhibiting effect was revealed through the formation of an adsorbed film, which blocked the active site present on the alloys. The adsorption process follows the Freundlich isotherm. The addition of Si to Al electrode increases in the corrosion protection of the alloys in the following sequence: Alloy II > Alloy I. The inhibition efficiencies obtained via different techniques are consistent with each other.

5-Amino-3-methyl-1-phenyl-1H-pyrazole-4-carbonitrile (1) was used as a precursor for preparation of 3-methyl-1-phenyl-1,5-dihydro-pyrazolo[3,4-d]pyrimidin-4-one (2) and its derivatives 3–10. The produced compounds were separated, purified, and characterized by FT-IR, 1HNMR, 13C NMR, and mass spectroscopy. The surface properties were studied by measuring the surface tension. The surface tension, critical micelle concentration (CMC), and surface activities were determined. The surface parameters such as surface excess concentration (Γmax), the area per molecule at interface (Amin), and the effectiveness of surface tension reduction (πCMC) were determined from the adsorption isotherms of the prepared compounds. Furthermore, the corrosion inhibition performance of the prepared compounds was evaluated by chemical methods (weight loss) at different inhibitor concentrations and different temperatures. The corrosion inhibition efficiency increased with increase in inhibitor concentration, but decreased with increase in temperature. Thermodynamic activation parameters were computed and discussed to reach the mechanism of the corrosion inhibition process.

Three compounds based on heterocyclic amides were synthesized, purified, characterized, and evaluated as corrosion inhibitors for carbon steel in 1.0 M H2SO4 solution using various techniques such as the weight loss, hydrogen evolution, thermometric, and potentiodynamic polarization. Effects of raising the concentration (50, 100, 150, 200 ppm) of amide compounds and temperatures were analyzed. The percentage inhibition efficiency went up with increasing inhibitor concentrations but decreased with temperature. Thermodynamic activation parameters were computed and discussed. It was found that the heterocyclic amide compounds reduce the weight loss, the amount of hydrogen evolved, the corrosion current density; thus the inhibition efficiency increases indicating the inhibiting power of these compounds. The maximum corrosion inhibition efficiency obtained by using 200 ppm from compound 3 is 95%. The potentiodynamic polarization curves proved that amide compounds act as inhibitors of a mixed type. The inhibition action of the three compounds was due to blocking the surface of the electrode by adsorption the inhibitor molecules according to the Langmuir isotherm. The data obtained via different techniques are in good agreement with each other and illustrate that the prepared amides can be considered to be potential nontoxic corrosion inhibitors.

Three compounds of azole derivatives were investigated as inhibitors for the dissolution of aluminum (Al) in 0.5 M HCl solution using electrochemical techniques, e.g., potentiodynamic polarization, electrochemical impedance spectroscopy electrochemical frequency modulation (EFM). The surface of Al was examined in the absence and presence of the some azole derivatives using scanning electron microscopy (SEM). The potentiodynamic polarization suggests that these compounds act as mixed type inhibitors because they enhance both the anodic and cathodic Tafel slopes. The inhibition efficiency (%IE), increased with increasing the concentration of inhibitors. SEM proved the surface of Al is improved due to the adsorption of the azole compounds on the surface of Al. The adsorption of the azole compounds on the Al surface is obeyed Frumkin isotherm. The sequence of the %IE increases in the following order 1,2,3-benztriazole > methyl imidazole > imidazole. The extent of inhibition depends on the molecular size of the molecule and the electron density of the substituent groups.

The new synthesized cationic Gemini surfactant (CGS) was tested as a corrosion inhibitor for carbon steel (CS) in 1.0 M hydrochloric acid using weight loss, electrochemical spectroscopy and potentiodynamic polarization. The inhibition efficiency is increased by increasing the CGS concentration and is almost constant within the temperature range studied. The inhibition was explained by adsorption of the CGS molecule on the CS surface. A mixed-type inhibitor is suggested for the inhibitory effects of CGS as revealed by the potentiodynamic polarization technique. The changes in impedance parameters suggested that the adsorption of the inhibitor on the CGS surface led to the formation of protective films. The adsorption of the CGS on the surface of CS obeys Langmuir adsorption isotherm. Thermodynamic and kinetic parameters were calculated and discussed.

The inhibiting power of three synthesized amino acids based-surfactant molecules, namely, sodium N-dodecyl asparagines (AS), sodium N-dodecylhistidine (HS) and sodium N-dodecyltryptophan (TS) on the dissolution of carbon steel was inspected in 0.5 M NaCl and 05 M NaOH solutions at 25 °C. The methods employed in this work were weight-loss (WL), potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS). The chemical structures of the synthesized surfactants were confirmed by FT-IR and 1HNMR. The inhibition efficiencies were found to increase as the surfactants concentrations increase, while decreasing with increasing the concentration of the corrosive media (NaCl & NaOH) and temperature. Results obtained from the different techniques revealed that the inhibition efficiency of the compound TS was higher than those of both AS and HS. The inhibition efficiencies of the synthesized surfactants were declined in terms of strong adsorption of surfactants on the surface of carbon steel and forming a protective film and such adsorption was found to obey Langmuir isotherm. Both thermodynamic and kinetic parameters were evaluated which support the mechanism of physical adsorption of the inhibitors. The tested surfactants were found to act as mixed-type inhibitors with anodic predominance. The surface morphology of the carbon steel surface was examined by scanning electron microscopy (SEM). The inhibitory mechanism of carbon steel corrosion was suggested. Results obtained from all employed methods are consistent with each other.

A novel compound, 2,6-bis-[1-(2-phenylhydrazono)ethyl]pyridine (BPEP), was synthesized and confirmed by NMR and IR spectroscopy. BPEP was examined as an inhibitor for the corrosion of zinc electrod...

The inhibiting power of three compounds of azole antifungal drugs to ward the dissolution of aluminum in 1.0 MHCl solutions was elaborated using chemical, electrochemical and theoretical investigation by DFT. The azole antifungal drugs to minimize the corrosion rate of Al by diminishing the values of weight loss, corrosion current density and double layer capacitance and the values the inhibition efficiency increases. Azole antifungal drugs behaved as mixed inhibitors. The adsorption of these drugs at the interface between the Al and the electrolyte solution are responsible for the inhibition process according to Temkin’s isotherm. The quantum chemical parameters studies supported the sequence of the percentage inhibition efficiency obtained by chemical and electrochemical measurements.

The inhibiting impact of natural aqueous extracts of some plants such as curcumin, parsley and cassia bark extracts for the corrosion of carbon steel (C-steel) in 0.5 M H2SO4 solution was inspected utilizing some techniques such as galvanostatic and potentiodynamic anodic polarization and weight loss measurements. Outcomes indicated that the percentage inhibition efficiency increases with increasing the concentration of the extract due to its horizontal adsorption on the C-steel surface. The process of adsorption is followed by the Temkin isotherm. These natural extracts acted as pitting corrosion inhibitors by shifting the pitting potential to more noble values. The sequence of inhibition efficiency of the natural extracts decreases in the following order: cassia bark extract > parsley extract > curcumin extract. This arrangement is related to the molecular size of the major components of the three natural extracts used.

The inhibiting effect of three compounds of pyrazolo[3,4-d] pyrimidnone derivatives toward the corrosion of carbon steel in 1.0M HCl solution was investigated using galvanostatic and potentiodynamic anodic polarization techniques. The rise of the concentration of the inhibitors and decreasing the temperature led to the greater of inhibition efficiency. The inhibiting action of these compounds was explicated on the footing of its adsorption on the carbon steel surface. The adsorption operation of these compounds was obeyed Langmuir isotherm. There is only one anodic peak during the anodic cyclic voltammogram This peak was elucidated due to the active dissolution of Fe as Fe2+. The percentage inhibition efficiency was computed from the values of peak current density.There is a good convention between the values of the percentage inhibition efficiency gained from the diverse techniques.These compounds inhibit the pitting corrosion of carbon steel by shifiting the pitting corrosion potential to more noble direction. The effect of elevation of temperature on the rate of corrosion in devoid of and containing these compounds was studied and some activated thermodynamic parameters were computed.