Nanocrystalline yttrium vanadate doped with trivalent europium ions, YVO4:Eu3+, was synthesized via the microemulsion mediated hydrothermal process. Laser selective excitation spectra were employed to probe the local environments of Eu3+ ions in YVO4 nanocrystals. The local environments of the dopant ions were diversified because of the surface effect in nanocrystals, which led to an increase in linewidth in excitation and emission spectra. Furthermore, the change of site symmetry from the interior to the surface of nanoparticles was clearly exhibited in the emission spectra of Eu3+ ions under different excitation wavelengths. The results show that the fluorescent behavior of doped Eu3+ ions may be a useful probe for detecting the surface effect in nanosize materials.

The optimum process for the separation and purification of Al 13 was investigated in detail in this paper. The various influencing factors were discussed. The experimental results show that the concentration and basicity (B, OH/Al ratio) of polyaluminum chloride (PACl), Al/SO 4 ratio, Ba/SO 4 ratio and ultrasonic reaction have different roles in the separation and purification of Al 13 . Moderate concentration of PACl with the basicity around 2.0 gives some benefits in the separation of Al 13 . An optimization condition has then been found to obtain high purity Al 13 by involving Al/SO 4 and Ba/SO 4 ratios of 1:1, and 3 h ultrasonic time. Further indication on the separation of Al 13 is also discussed.

Biomimetic mineralization can lead to advanced crystalline composites with common chemicals under ambient conditions. An exceptional example is biomimetic nacre with its superior fracture toughness. The synthesis of the prismatic layer with stiffness and wear resistance nonetheless remains an elusive goal. Herein, we apply a biomimetic mineralization method to grow prismatic-type CaCO3 thin films, mimicking their biogenic counterparts found in mollusk shells with a three-step pathway: coating a polymer substrate, deposition of a granular transition layer, and mineralization of a prismatic overlayer. The synthetic prismatic overlayers exhibit structural similarity and comparable hardness and Young’s modulus to their biogenic counterparts. Furthermore, employment of a biomacromolecular soluble additive, silk fibroin, in fabrication of the prismatic thin films leads to micro-/nano-textures with enhanced toughness and emerging under-water superoleophobicity. This study highlights the crucial role of the granular transition layer in promoting competition growth of the prismatic layer.

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