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    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.
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    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.