The interaction of methylene blue (MB) dye with natural coal (collected from coal landfills of the Kosovo Energy Corporation) in aqueous solutions was studied using adsorption, kinetics, and thermodynamic data, and Monte Carlo (MC) calculations. In a batch procedure, the effects of contact duration, initial MB concentration, pH, and solution temperature on the adsorption process were examined. The Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich (D-R) isotherms were used to examine the equilibrium adsorption data. The equilibrium data fit well to the Freundlich and Langmuir adsorption isotherm models; however, the Freundlich model suited the adsorption data to a slightly better extent than the Langmuir model. The kinetics experimental data was fitted using pseudo-first-order, first-order, pseudo-second-order, second-order, Elvoich equation, and diffusion models. The pseudo-second-order rate model manifested a superlative fit to the experimental data, while the adsorption of MB onto coal is regulated by both liquid film and intraparticle diffusions at the same time. Thermodynamic parameters, such as Gibbs free energy (Δ), enthalpy (Δ), and entropy (Δ) were calculated. The adsorption of MB was confirmed to be spontaneous and endothermic. The theoretical results were in agreement with the experimental ones.
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http://dx.doi.org/10.3390/molecules27061856 | DOI Listing |
JACS Au
January 2025
School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.
Mechanochemistry and mechanocatalysis are gaining increasing attention as environmentally friendly chemical processes because of their solvent-free nature and scalability. Significant effort has been devoted for studying continuum-scale phenomena in mechanochemistry, such as temperature and pressure gradients, but the atomic-scale mechanisms remain relatively unexplored. In this work, we focus on the mechanochemical reduction of MoO as a case study.
View Article and Find Full Text PDFChem Sci
January 2025
Department of Chemistry, University of York York YO10 5DD UK
C-N atropisomeric amides are important compounds in medicinal chemistry and agrochemistry. Atropselective methods for their synthesis are therefore important. In this study, a novel strategy to make C-N atropisomeric amides based on intramolecular acyl transfer a tethered Lewis basic pyridine or tertiary amine group is reported.
View Article and Find Full Text PDFRSC Adv
January 2025
Research Laboratory in Subterranean and Surface Hydraulics, University of Biskra PO Box 145 RP Biskra Algeria.
This investigation aims to apply the adsorption process to eliminate mequitazine and ethinylestradiol, the active molecules of Primalan and Diane, respectively, from aqueous solutions, utilizing biochar synthesized from pumpkin fruits (PB-500). The results revealed that the obtained adsorbent possessed a notable specific surface area, contributing to removal efficiencies of 66.61% and 62.
View Article and Find Full Text PDFNat Commun
January 2025
Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland.
Jumping of coalescing condensate droplets from superhydrophobic surfaces is an interesting phenomenon which yields marked heat transfer enhancement over the more explored gravity-driven droplet removal mode in surface condensation, a phase change process of central interest to applications ranging from energy to water harvesting. However, when condensate microdroplets coalesce, they can also spontaneously propel themselves omnidirectionally on the surface independent of gravity and grow by feeding from droplets they sweep along the way. Here we observe and explain the physics behind this phenomenon of roaming of coalescing condensate microdroplets on solely nanostructured superhydrophobic surfaces, where the microdroplets are orders of magnitude larger than the underlaying surface nanotexture.
View Article and Find Full Text PDFJ Org Chem
January 2025
Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
The selective oxidative cleavage and functionalization of C(OH)-C bonds in tertiary alcohols harbor immense feasibility in organic synthesis and enable the production of high value-added chemicals from renewable biomass. However, it remains a challenge, owing to the inherent kinetic inertness and thermodynamic stability of C(OH)-C bonds and the lack of C-H. Taking the huge potential and challenge of C(OH)-C bond activation and functionalization into consideration, herein, we show the first example of an inexpensive bifunctional ferric nitrate catalyst for catalytic direct oxidation of structurally distinct tertiary alcohols to esters with environmentally benign molecular oxygen as an oxidant and MeOH as a solvent, without the assistance of any additives.
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