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Öğe Carbon Dots in Stationary Phase of Chromatography, Enhanced Crop Yield, and Stationary Phase of Chromatography(American Chemical Society, 2024) Rbaa, M.; Hsissou, R.; Dahmani, K.; Oubaaqa, M.; Tüzün, B.; Berdimurodov, E.; Rouifi, Z.The scientific research area has been paying close attention to carbon dots (CDs) over the last decade. They perform exceptional optical and chemical properties because of their size-dependent quantum confinement effects, minimal toxicity, improved biocompatibility, and favorable charge and electric conductivity. So, they provide a unique affinity for different analytes, and high surface coverage makes them a promising alternative for different chromatographic methods, such as high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC), which are useful in fields such as chemistry, biochemistry, pharmaceuticals, forensics, environmental analysis, and more. This chapter focuses on understanding how CDs can improve the interaction between the stationary phase and the analytes, to explain the compounds’ rather interesting separation efficiency, selectivity, and sensitivity during chromatographic analyses. Then, we expose the criteria of choice of some examples of conventional stationary phases used in different chromatographic techniques and stationary phases, in terms of selectivity and efficiency of the separation. It therefore explains the processes involved in separating and quantifying the components of a chemical mixture using the chromatography technique, while discussing the advantages of using carbon dots as stationary phases. At last, we have compiled the properties of CDs in terms of remarkable photoluminescence, high quantum yield, low toxicity, small size, appreciable biocompatibility, and abundance sourced from low-cost carbon. These have been used to explain their separation efficiency, selectivity, and sensitivity to chromatographic analysis. In short, this chapter supports the use of carbon-dot-containing stationary phases over conventional stationary phases as a powerful analytical prospect, particularly for improving chromatography yield and stationary phase. © 2024 American Chemical Society.Öğe Electrochemical, Characterization, and Quantum Chemical Studies of Two Newly Synthesized Aromatic Aldehydes-Based Xanthene Diones as Corrosion Inhibitors for Mild Steel in 1 M Hydrochloric Acid(Springer Science and Business Media Deutschland GmbH, 2023) Galai, M.; Touhami, M. Ebn; Oubaaqa, M.; Dahmani, K.; Ouakki, M.; Khattabi, M.; Benzekri, Z.The inhibiting effect of two newly synthesized inhibitors, namely 3,3,6,6-tetramethyl-9-phenyl-3,4,6,7-tetrahydro-2H-xanthenes-1,8(5H,9H)-dione (ZM-1) and 9-(4-Bromophenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-2H-xanthene-1,8-dine (ZM-2) on mild steel (MS) corrosion in 1 M HCl solution has been examined. For this purpose, Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Polarization measurements (PP) have been carried out. Furthermore, theoretical chemistry concepts have been used to calculate and analyze the molecule’s quantum parameters. This has been accomplished using Density Functional Theory (DFT). Molecular Dynamic Simulation has been used to interpret the inhibiting action mode. It has been perceived that the increase of inhibitor concentration managed to significant corrosion rate reduction of MS in 1 M HCl, with inhibitive efficiency values reaching, respectively, 84% and 87% at 10?3 M inhibitor concentrations of ZM-1 and ZM-2. The inhibition efficiency is augmented with an inhibitor concentration increase. Temperature influence on the corrosion behavior of MS in 1 M HCl at the inhibitor’s optimal concentration of 10?3 M was studied in the range of temperature 298–328 K. Polarization plots showed that ZM-1 and ZM-2 acted as mixed-type inhibitors. The adsorption mechanism of the studied inhibitors was consistent with the Langmuir isotherm model. The corroded surface has also been analyzed by SEM/EDX; AFM, contact angle, and XRD techniques. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.Öğe Functionalization effect on the corrosion inhibition of novel eco-friendly compounds based on 8-hydroxyquinoline derivatives: Experimental, theoretical and surface treatment(Elsevier, 2021) Galai, M.; Rbaa, M.; Ouakki, M.; Dahmani, K.; Kaya, S.; Arrousse, N.; Dkhireche, N.The present study has investigated the functional effect of modifying a simple function (-NH2) that correspond to a heterocycle (Benzodiazepine), acquired through two similar reactions, on the inhibition of mild steel corrosion (m-steel) in hydrochloric medium (1.0 M HCl). [5-((2-aminobutoxy) methyl)-quinolin-8-ol (Q-2) and 7-chloro-2,2,4-trimethyl-2,3 dihydro-1H benzo[b][1,4]diazepin-1-yl)methyl)quinolin-8-ol (Q-1)] were synthesized by two environmentally friendly reactions and characterized using Proton nuclear magnetic resonance (1H NMR) and Carbon nuclear magnetic resonance (13C NMR) spectroscopy. The inhibitory action of both organic compounds was evaluated by numerous techniques that have been already described in the literature (electrochemical impedance spectroscopy (EIS) and Potentiodynamic Polarization (PDP)).The inhibition efficiency increased with the increasing inhibitor concentration to 92.8% and91.1 % for Q-1 and Q-2 respectively at 10-3 M. The submerged surface of steel has been identified by scanning electron microscopy coupled with Energy Dispersive X-Ray Spectroscopy (SEM/EDS), Infrared spectroscopy (FT-IR), atomic force microscopy (AFM) spectroscopy and Contact angle measurements (theta). The corrosive solutions after corrosion tests have been identified by UV-visible spectrometry (UV-vis) and Inductively Coupled Plasma Emission Spectroscopy analysis (ICP-OES). The experimental studies PDP and EIS were completed by the theoretical studies Density-functional theory (DFT) and Monte Carlo (MC) simulation). Experimental data have shown that the studied additives Q-1 and Q-2 are effective against the corrosion acid of m-steel. In addition, their adsorption onto steel surface follow Langmuir adsorption isotherm.Öğe New Xanthene Diones Compounds as a Corrosion Inhibitor of Mild Steel in Acid Medium: Electrochemical, Surface Characterization and Theoretical Insights(Springernature, 2023) Dahmani, K.; Galai, Mouhsine; Ouakki, M.; Benzekri, Z.; El Magri, A.; Iachhab, R.; Kaya, S.Two newly synthesized inhibitors, namely 3,3,6,6-tetramethyl-9-phenyl-3,4,6,7-tetrahydro-2H-xanthenes-1,8 (5H,9H)-dione (ZM-3) and 9-(4-Bromophenyl)-3,3,6,6-tetramethl-3,4,5,6,7,9-hexahydro-2H-xanthene-1,8-dine (ZM-4) have been reported in the current study as a promising corrosion inhibitors of mild steel (MS) in 1 M HCl solution. Electrochemical experiments such as Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic Polarization measurements (PP) were performed for this aim. The quantum properties of the molecules were also calculated and analyzed using theoretical chemistry principles. Density Functional Theory was used in order to achieve this (DFT). The inhibitory action mechanism was discovered using Molecular Dynamic Simulation (MDS). The increase of the inhibitor concentration was thought to have resulted in a considerable reduction in MS corrosion rate in molar hydrochloric acid solution, with inhibitive efficiency values of 90.8 and 91.3% at 10(-3) M inhibitor concentrations of ZM-3 and ZM-4, respectively. As the inhibitor concentration was increased, the inhibition effectiveness improved. Using temperatures ranging from 298 to 328 K, the effect of temperature on the corrosion behavior of MS in molar HCl at the inhibitor's optimum concentration of 10(-3) was investigated. ZM-3 and ZM-4 behaved as mixed type inhibitors, according to polarization plots. The Langmuir isotherm model fit the adsorption mechanism of the evaluated inhibitors. Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis (SEM/EDX), Atomic force microscopy (AFM), contact angle, and X-ray Powder Diffraction (XRD) methods were used to examine the corroded surface.Öğe Novel 8-hydroxyquinoline compounds used to inhibit mild steel corrosion in the presence of hydrochloric acid 1.0 M: an experimental and theoretical electrochemical study(Taylor and Francis Ltd., 2025) Bouabbadi, A.; Rbaa, M.; Tüzün, B.; Hmada, A.; Dahmani, K.; Kharbouch, O.; Galai, M.The present study examined the corrosion inhibition property of two derivatives of 8-hydroxyquinoline, namely diethyl 1,1-(4-(4-chlorophenyl)-1-((8-hydroxyquinoline-5-yl)methyl)-2, 6-dimethyl-1, 4-dihydropyridine-3,5-diyl) diethanone (P1) and diethyl 1,1-(4-(4-bromophenyl)-1-((8-hydroxyquinoline-5-yl)methyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-diyl)diethanone (P2). against mild steel (MS) degradation in 1.0 M hydrochloric acid (HCL) solution. The study was carried out using electrochemical techniques such as dynamic potential polarisation (DPP) and impedance spectroscopy (EIS) at different temperatures (298–328 K). Inhibition efficiency (IE %) increased with inhibitor concentration, reaching 97.0% for P1 and 91.8% for P2 at 10−3 M (298 K). Impedance measurements indicated that charge transfer resistance (Rct) increased, while double-layer capacitance (Cdl) decreased with increasing concentration of P1 and P2. Analysis of the polarisation curves shows that P1 and P2 act as mixed-type inhibitors. According to the Langmuir isotherm and thermodynamic parameters, P1 and P2 are adsorbed onto the mild steel surface by chemical interactions. The SEM/EDX analysis results revealed the formation of an adsorption film on MS. DFT calculations show that free heteroatom doublets of oxygen (O) and nitrogen (N) promote electron sharing between the molecules studied and the steel surface. Data from theoretical methods (DFT) confirm the experimental results. © 2025 Canadian Institute of Mining, Metallurgy and Petroleum.Öğe Quantum chemical and molecular dynamic simulation studies for the identification of the extracted cinnamon essential oil constituent responsible for copper corrosion inhibition in acidified 3.0 wt% NaCl medium(Elsevier, Şubat 2021) Dahmani, K.; Galai, M.; Ouakki, M.; Cherkaoui M.; Touir, R.; Erkan, Sultan; Kaya, Savaş; El Ibrahimi, B.The influence of the extracted cinnamon essential oil (CiO) on the copper corrosion resistance in acidified 3.0 wt% NaCl (pH = 2) medium was investigated by using electrochemical measurements and Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDS). So, in order to identify the component of CiO responsible for corrosion inhibition of copper in corrosive solution, the density functional theory (DFT) calculations and molecular dynamics simulation were used. Potentiodynamic polarization showed that the tested natural product acts as cathodic-type inhibitor. Electrochemical impedance spectroscopy indicated that the inhibition efficiency increases with CiO concentrations to get up a maximum value of 89% at 200 ppm. In addition, SEM/EDS analysis in the presence of 200 ppm CiO indicated that copper surface was exempt for all corrosion products, confirming its offered protection. Finally, the major calculated quantum chemical descriptors obtained from DFT calculations indicated that the anticorrosion efficiency responsibility attributes to P8 and P46, with the predominance of P8. In the same, the molecular dynamics simulation indicated that the adsorption energy follows the order: P5 (-61.071 kJ mol−1) > P46 (-58.070 kJ mol−1) > P8 (-42.938 kJ mol−1) on Cu (1 1 1) and P8 (-21.220 kJ mol−1) > P46 (-20.066 kJ mol−1) > P5 (-19.591 kJ mol−1) on CuO2 (1 1 0), suggesting a strong adsorption of P8 on oxide copper (1 1 0) surface and consequently therefore the performance of extracted CiO can be attributed to P8, which is parallel to the copper (1 1 1) surface contrary to other molecules P46 and P5.
