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Nanoporous titanium dioxide was synthesized by a hydrothermal method without using of surfactant or template. The structure, morphology, surface chemical states and specific surface area were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and N 2 adsorption-desorption isotherms, respectively. The as-synthesized products are anatase-TiO 2 with small grain size (about 12.27 nm) and high surface area (147.17 m 2 g −1 ). The as-synthesized porous TiO 2 powder was used to fabricate indirect-heating gas sensor whose gas-sensing characteristics toward acetone were investigated. At its optimal operation temperature, the sensor possesses a good sensitivity, selectivity, linear dependence, low detection limitation, and response/recovery, repeatability as well as long-term stability. Especially for the high sensitivity and fast response/recovery, its response reaches 25.97 for 500 ppm acetone, which is several times higher that of the reported TiO 2 -based sensors. The response and recovery times are only 13 and 8 s, respectively. Those values demonstrate the potential of using as-synthesized TiO 2 for acetone gas detection, particularly in the dynamic monitoring. Apart from these, the mechanism related to the advanced properties was also investigated and presented. [ABSTRACT FROM AUTHOR]

• Solubility of aprepitant (form I) in four aqueous mixtures was determined and correlated. • Preferential solvation of aprepitant (form I) were derived via IKBIs method applied to solubility. • Solvent effect on solubility variation was investigated through KAT-LSER model. This contribution reported the equilibrium solubility of aprepitant (form I) in four binary aqueous mixtures of methanol, ethanol, acetone and 1,4-dioxane acquired through a shake-flask method from 283.15 K to 323.15 K under local atmospheric pressure of 101.2 kPa. At the same mass fraction compositions of methanol/ethanol/acetone/1,4-dioxane and temperature, the mole fraction solubility of aprepitant was greater in (1,4-dioxane + water) mixture than in ethanol/acetone/methanol (1) + water (2) mixtures. The relative importance of solute-solvent and solvent-solvent interactions upon the solubility variation was studied by using the linear solvation energy relationships of solvent effect. The Hildebrand solubility parameter and dipolarity-polarizability of the solvents had the main contributions to the solubility variation in methanol/ethanol/1,4-dioxane + water mixtures; while merely dipolarity-polarizability, in (acetone + water) mixture. The preferential solvation was studied by using the method of inverse Kirkwood-Buff integrals in terms of thermodynamic solution properties. The preferential solvation parameters for methanol, ethanol, acetone and 1,4-dioxane presented positive values in methanol/ethanol/acetone/1,4-dioxane-rich and intermediate compositions in the four mixtures, indicating that aprepitant (I) was solvated preferentially by the methanol/ethanol/acetone/1,4-dioxane. It is conjecturable that in these regions aprepitant (I) acts as a Lewis acid with methanol/ethanol/acetone/1,4-dioxane molecules. Moreover, the drug's solubility was mathematically represented via the Jouyban-Acree model obtaining the average relative deviations less than 6.21%. Finally, the standard dissolution enthalpies (Δ H sol o) for aprepitant (I) dissolved in solvent mixtures were obtained from the van't Hoff analysis. [ABSTRACT FROM AUTHOR]