The densities and viscosities for mixtures of 1-n-butyl-3-methylimidazolium tetrafluoroborate ionic liquid with acetonitrile, dichloromethane, 2-butanone and N,N-dimethylformamide have been determined at 298.15 K. From these measurements, it was found that viscosities of the mixtures can generally be described by an exponential equation. Their densities are linear functions of the mass fraction of the ionic liquid in the mixtures. These physical properties can be predicted as a function of the concentration of ionic liquid provided that the properties for pure components are known. The excess molar volume V E m and the excess logarithm viscosities (ln h) E were calculated and fitted to the Redlich-Kister polynomials. It is shown that the values of V E m are negative but those of (ln h) E are positive. Surprisingly, the minimum in V E m and the maximum in (ln h) E are observed at about the same mole fraction of the ionic liquid, x ≈ 0.3. The results are discussed in terms of the ion-dipole interactions between the cations of the ionic liquid and the organic solutes.

Mesoporous TiO2 microspheres with controllable phase junctions have been synthesized by a facile coordination-mediated self-assembly method.

Because of their low cost, natural abundance, environmental benignity, plentiful polymorphs, good chemical stability and excellent optical properties, TiO2 materials are of great importance in the areas of physics, chemistry and material science. Much effort has been devoted to the synthesis of TiO2 nanomaterials for various applications. Among them, mesoporous TiO2 materials, especially with hierarchically porous structures, show great potential owing to their extraordinarily high surface areas, large pore volumes, tunable pore structures and morphologies, and nanoscale effects. This review aims to provide an overview of the synthesis and applications of hierarchically mesoporous TiO2 materials. In the first section, the general synthetic strategies for hierarchically mesoporous TiO2 materials are reviewed. After that, we summarize the architectures of hierarchically mesoporous TiO2 materials, including nanofibers, nanosheets, microparticles, films, spheres, core-shell and multi-level structures. At the same time, the corresponding mechanisms and the key factors for the controllable synthesis are highlighted. Following this, the applications of hierarchically mesoporous TiO2 materials in terms of energy storage and environmental protection, including photocatalytic degradation of pollutants, photocatalytic fuel generation, photoelectrochemical water splitting, catalyst support, lithium-ion batteries and sodium-ion batteries, are discussed. Finally, we outline the challenges and future directions of research and development in this area.