Despite some unavoidable defects, the comparison between the simulated and experimental results validates the DMC-S aggregate model and lays a solid foundation for an in-depth study of DMC and its reactivity.The Allura red AC (ARAC) dye adsorption onto natural sawdust (NSD) and hexadecylpyridinium bromide-treated sawdust (MSD) was investigated in aqueous solution as a function of contact time, solution pH, particle size, adsorbent dosage, dye concentration, temperature, and ionic strength. The adsorbents were characterized by Fourier transform infrared spectroscopy and X-ray diffraction crystallography. The dye adsorption onto both adsorbents was confirmed by field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. The maximum dye adsorption was found within 120 min at pH 2.0 for NSD and pH 3.0 for MSD, respectively, with a particle size of 0-75 μm and an adsorbent dosage of 0.07 g/50 mL ARAC dye solution (50 μmol/L). https://www.selleckchem.com/products/irpagratinib.html The batch adsorption kinetic data were followed by the pseudo-second-order kinetic model rather than the pseudo-first-order and Elovich kinetic models. Equilibrium adsorption isotherms were explained by the Langmuir isotherm model, and the maximum extent of adsorption was found to be 52.14 μmol/g for NSD and 151.88 μmol/g for MSD at 55 °C. The values of activation energy (E a) and thermodynamic parameters (ΔG ⧧, ΔH ⧧, ΔS ⧧, ΔG°, ΔH° and ΔS°) proved that the ARAC dye adsorption onto both adsorbents NSD and MSD is a spontaneous-endothermic physisorption process. ARAC (98-99%) was released from dye-loaded adsorbents in aqueous solution (pH ≥ 12) within 120 min. The adsorbents NSD and MSD were reused for a second time without significant loss of their adsorption efficiency.A hydrazone ligand, (E)-6-(2-((2-hydroxynaphthalen-1-yl)methylene)hydrazinyl)nicotinohydrazide (H2L), was synthesized and characterized by spectroscopic methods. The reaction of H2L with CuCl2·2H2O in methanol gave Cu(II) coordination compound, [Cu(HL')(Cl)]·CH3OH (1), which was characterized by elemental analysis and spectroscopic methods (Fourier transform infrared (FT-IR) and UV-vis). The structure of 1 was also determined by single-crystal X-ray analysis. Structural studies confirmed the formation of esteric group during the synthesis of 1. Compound 1 was immobilized on 3-aminopropyltriethoxysilane (APTS)-functionalized silica gel through the amidification reaction and the obtained heterogeneous coordination compound was utilized as a catalyst for the three-component azide-epoxide-alkyne cycloaddition reaction in water as a green solvent. The structural properties of the heterogeneous catalyst were characterized by a combination of FT-IR, UV-vis, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS) analyses. The effect of the amount of catalyst and temperature on the cycloaddition reaction was studied, and the obtained 1,2,3-triazoles were characterized by spectroscopic studies and single-crystal X-ray analysis. The catalytic investigations revealed that this catalytic system has high activity in the synthesis of β-hydroxy-1,2,3-triazoles. It was also found that the aromatic and aliphatic substituents on the alkyne and epoxide together with the reaction temperature have considerable effects on the activity and regioselectivity of this catalytic system.In a new and environmentally sustainable approach, a series of 2-arylimidazo[1,2-a]pyridine derivatives were synthesized in aqueous media in the presence of iodine as a catalyst. The reaction proceeded by condensation of various aryl methyl ketones with 2-aminopyridines to afford 2-arylimidazo[1,2-a]pyridines in good overall yields. Although several of the reactions were efficiently performed "on water", the addition of a surfactant, namely, sodium dodecyl sulphate , was found effective in terms of substrate scope and yield enhancement. Both methods were successfully used for the gram-scale synthesis of a marketed drug, zolimidine. The simple experimental setup, water as "green" media, and inexpensive catalyst are some of the merits of this protocol.H2S is abundantly available in nature, and it is a common byproduct in industries. Molybdenum sulfides have been proved to be active in the catalytic decomposition of hydrogen sulfide (H2S) to produce hydrogen. In this study, density functional theory (DFT) calculations are carried out to explore the reaction mechanisms of H2S with MS3 (M = Mo, W) clusters. The reaction mechanism of H2S with MoS3 is roughly the same as that of the reaction with WS3, and the free-energy profile of the reaction with MoS3 is slightly higher than that of the reaction with WS3. The overall driving forces (-ΔG) are positive, and the overall reaction barriers (ΔG b) are rather small, indicating that such H2 productions are product-favored. MS3 (M = Mo, W) clusters have clawlike structures, which have electrophilic metal sites to receive the approaching H2S molecule. After several hydrogen-atom transfer (HAT) processes, the final MS4·H2 (IM-4) complexes are formed, which could desorb H2 at a relatively low temperature. The singlet product MS4 clusters contain the singlet S2 moiety, similar to the adsorbed singlet S2 on the surface of sulfide catalysts. The theoretical results are compared with the experiments of heterogeneous catalytic decomposition of H2S by MoS2 catalysts. Our work may provide some insights into the optimal design of the relevant catalysts.After large-scale and long-term waterflooding, reservoir physical properties such as the pore throat structure and rock wettability may change. In this paper, the relative permeability curves under different water injection volumes through core-flood experiments were used to characterize the comprehensive changes of various reservoir physical properties at high water-cut stage. The novel concept of "water cross-surface flux" was proposed to characterize the cumulative flushing effect on the reservoir by injected water, and a novel method for inverted five-spot reservoir simulation at high water-cut stage based on time-varying relative permeability curves was established. From the relative permeability curves measured through two cores from the X oilfield under different water injection volumes (100, 500, 1000, 1500, and 2000 PV), it is found that with the increase of injected water volume, the two-phase co-flow zone becomes wider, the water permeability under residual oil saturation increases, and the residual oil saturation decreases.
Despite some unavoidable defects, the comparison between the simulated and experimental results validates the DMC-S aggregate model and lays a solid foundation for an in-depth study of DMC and its reactivity.The Allura red AC (ARAC) dye adsorption onto natural sawdust (NSD) and hexadecylpyridinium bromide-treated sawdust (MSD) was investigated in aqueous solution as a function of contact time, solution pH, particle size, adsorbent dosage, dye concentration, temperature, and ionic strength. The adsorbents were characterized by Fourier transform infrared spectroscopy and X-ray diffraction crystallography. The dye adsorption onto both adsorbents was confirmed by field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. The maximum dye adsorption was found within 120 min at pH 2.0 for NSD and pH 3.0 for MSD, respectively, with a particle size of 0-75 μm and an adsorbent dosage of 0.07 g/50 mL ARAC dye solution (50 μmol/L). https://www.selleckchem.com/products/irpagratinib.html The batch adsorption kinetic data were followed by the pseudo-second-order kinetic model rather than the pseudo-first-order and Elovich kinetic models. Equilibrium adsorption isotherms were explained by the Langmuir isotherm model, and the maximum extent of adsorption was found to be 52.14 μmol/g for NSD and 151.88 μmol/g for MSD at 55 °C. The values of activation energy (E a) and thermodynamic parameters (ΔG ⧧, ΔH ⧧, ΔS ⧧, ΔG°, ΔH° and ΔS°) proved that the ARAC dye adsorption onto both adsorbents NSD and MSD is a spontaneous-endothermic physisorption process. ARAC (98-99%) was released from dye-loaded adsorbents in aqueous solution (pH ≥ 12) within 120 min. The adsorbents NSD and MSD were reused for a second time without significant loss of their adsorption efficiency.A hydrazone ligand, (E)-6-(2-((2-hydroxynaphthalen-1-yl)methylene)hydrazinyl)nicotinohydrazide (H2L), was synthesized and characterized by spectroscopic methods. The reaction of H2L with CuCl2·2H2O in methanol gave Cu(II) coordination compound, [Cu(HL')(Cl)]·CH3OH (1), which was characterized by elemental analysis and spectroscopic methods (Fourier transform infrared (FT-IR) and UV-vis). The structure of 1 was also determined by single-crystal X-ray analysis. Structural studies confirmed the formation of esteric group during the synthesis of 1. Compound 1 was immobilized on 3-aminopropyltriethoxysilane (APTS)-functionalized silica gel through the amidification reaction and the obtained heterogeneous coordination compound was utilized as a catalyst for the three-component azide-epoxide-alkyne cycloaddition reaction in water as a green solvent. The structural properties of the heterogeneous catalyst were characterized by a combination of FT-IR, UV-vis, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS) analyses. The effect of the amount of catalyst and temperature on the cycloaddition reaction was studied, and the obtained 1,2,3-triazoles were characterized by spectroscopic studies and single-crystal X-ray analysis. The catalytic investigations revealed that this catalytic system has high activity in the synthesis of β-hydroxy-1,2,3-triazoles. It was also found that the aromatic and aliphatic substituents on the alkyne and epoxide together with the reaction temperature have considerable effects on the activity and regioselectivity of this catalytic system.In a new and environmentally sustainable approach, a series of 2-arylimidazo[1,2-a]pyridine derivatives were synthesized in aqueous media in the presence of iodine as a catalyst. The reaction proceeded by condensation of various aryl methyl ketones with 2-aminopyridines to afford 2-arylimidazo[1,2-a]pyridines in good overall yields. Although several of the reactions were efficiently performed "on water", the addition of a surfactant, namely, sodium dodecyl sulphate , was found effective in terms of substrate scope and yield enhancement. Both methods were successfully used for the gram-scale synthesis of a marketed drug, zolimidine. The simple experimental setup, water as "green" media, and inexpensive catalyst are some of the merits of this protocol.H2S is abundantly available in nature, and it is a common byproduct in industries. Molybdenum sulfides have been proved to be active in the catalytic decomposition of hydrogen sulfide (H2S) to produce hydrogen. In this study, density functional theory (DFT) calculations are carried out to explore the reaction mechanisms of H2S with MS3 (M = Mo, W) clusters. The reaction mechanism of H2S with MoS3 is roughly the same as that of the reaction with WS3, and the free-energy profile of the reaction with MoS3 is slightly higher than that of the reaction with WS3. The overall driving forces (-ΔG) are positive, and the overall reaction barriers (ΔG b) are rather small, indicating that such H2 productions are product-favored. MS3 (M = Mo, W) clusters have clawlike structures, which have electrophilic metal sites to receive the approaching H2S molecule. After several hydrogen-atom transfer (HAT) processes, the final MS4·H2 (IM-4) complexes are formed, which could desorb H2 at a relatively low temperature. The singlet product MS4 clusters contain the singlet S2 moiety, similar to the adsorbed singlet S2 on the surface of sulfide catalysts. The theoretical results are compared with the experiments of heterogeneous catalytic decomposition of H2S by MoS2 catalysts. Our work may provide some insights into the optimal design of the relevant catalysts.After large-scale and long-term waterflooding, reservoir physical properties such as the pore throat structure and rock wettability may change. In this paper, the relative permeability curves under different water injection volumes through core-flood experiments were used to characterize the comprehensive changes of various reservoir physical properties at high water-cut stage. The novel concept of "water cross-surface flux" was proposed to characterize the cumulative flushing effect on the reservoir by injected water, and a novel method for inverted five-spot reservoir simulation at high water-cut stage based on time-varying relative permeability curves was established. From the relative permeability curves measured through two cores from the X oilfield under different water injection volumes (100, 500, 1000, 1500, and 2000 PV), it is found that with the increase of injected water volume, the two-phase co-flow zone becomes wider, the water permeability under residual oil saturation increases, and the residual oil saturation decreases.
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