Volumetric, Viscometric, and Refractive Index Behavior of 7‑Hydroxy-4-methylcoumarin in Aqueous Ethanol or 1‑Propanol Solutions in the Temperature Range of (293.15 to 313.15) K

Densities and viscosities of the pseudo binary system 7-hydroxy-4-methylcoumarin + (ethanol or 1-propanol) + water at temperatures of (293.15, 298.15, 303.15, 308.15, and 313.15) K and refractive indices of this system at <i>T</i> = 298.15 K have been measured as a function of the molality of 7-hydroxy-4-methylcoumarin. The density data have been used to compute the apparent molar volume and limiting partial molar volume. The viscosity <i>B</i>-coefficients and variation of <i>B</i> with temperature have been calculated from the viscosity data according to the Jones–Dole equation. Molar refractions of the investigated system have been obtained from the refractive index data. These parameters and their variation tendencies have been expounded in terms of the interactions between solutes and solvents. The results have shown that 7-hydroxy-4-methylcoumarin plays a structure-making role in the given solution

Solvent and pH Dependences of Mixing Enthalpies of <i>N</i>‑Glycylglycine with Protocatechuic Acid

Protocatechuic acid (PA) is a natural phenolic compound which has been proven to have chemopreventive property against chemically induced carcinogenesis. The mixing enthalpies of PA with <i>N</i>-glycylglycine in sodium phosphate and potassium phosphate buffer solutions with different pH values have been investigated by mixing-flow isothermal microcalorimetry at <i>T</i> = 298.15 K. The heterotactic enthalpic interaction coefficients (<i>h</i>_<i>xy</i>) in the pH range of phosphate buffer solution from 3.0 to 8.0 have been calculated according to the McMillan–Mayer theory. Trends of the enthalpic pairwise interaction coefficients (<i>h</i>_<i>xy</i>) with increasing pH in both phosphate buffer solutions were obtained. The solvent and pH dependence of the <i>h</i>_<i>xy</i> were discussed in terms of molecular interactions between solvated solute molecules

Thermodynamic Difference between Protocatechualdehyde and <i>p</i>‑Hydroxybenzaldehyde in Aqueous Sodium Chloride Solutions

The enthalpies of dilution of protocatechualdehyde and <i>p</i>-hydroxybenzaldehyde in the aqueous sodium chloride solutions were measured by using a mixing-flow microcalorimeter at 298.15 K. Densities of the ternary homogeneous systems at different temperatures (293.15, 298.15, 303.15, 308.15, and 313.15 K) were also measured with a quartz vibrating-tube densimeter. The homogeneous enthalpic interaction coefficients (<i>h</i>₂, <i>h</i>₃, and <i>h</i>₄) were calculated according to the excess enthalpy concept based on the calorimetric data. The apparent molar volumes (<i>V</i>_ϕ) and standard partial molar volumes (<i>V</i>_ϕ⁰) of the investigated system were computed from their density data. The variation trends in <i>h</i>₂ and <i>V</i>_ϕ⁰ with increasing salt molality were obtained and discussed in terms of the (solute + solute) and (solute + solvent) interactions. The experimental results showed that the molecular structures of protocatechualdehyde and <i>p</i>-hydroxybenzaldehyde, especially the number of hydroxyl groups, have evident influence on their thermodynamic properties. The thermodynamic data obtained in this work may be helpful for exploring the structure–function relationship of protocatechualdehyde and <i>p</i>-hydroxybenzaldehyde

Additional file 1: Figures S1–S6. of Facile Fabrication of Bi2WO6/Ag2S Heterostructure with Enhanced Visible-Light-Driven Photocatalytic Performances

The EDS, BET surface area, and Zeta potential analysis for the as-formed heterostructures, the XRD pattern of Ag2S, and the temporal evolution of Rh B absorption spectra over Bi2WO6/Ag2S heterostructure at different pH values. Figure S1. Elemental mapping and EDX spectra of the Bi2WO6/Ag2S heterostructure. Figure S2. EDS spectra of the composite photocatalysts Bi2WO6/Ag2S. Figure S3. Nitrogen adsorption-desorption isotherms and the pore size distribution curve (inset) of sample (a) Bi2WO6 and (b) Bi2WO6/Ag2S. Figure S4. XRD pattern of Ag2S. Figure S5. Zeta potential for a suspension containing 1 g L of sample Bi2WO6/Ag2S in the presence of KCl (10−3 M) at different pH values. Figure S6. The temporal evolution of Rh B absorption spectra over Bi2WO6/Ag2S heterostructure at different pH values