ИСТИНА

Titania microspheres are a perspective object for the fabrication of high performance liquid chromatography (HPLC) columns. The usual material for this application are silica microspheres of ⌀ 1-10 μm. The proposed method of Ti( n BuO) 4 controlled hydrolysis allows one to obtain titania microspheres with high specific surface area (up to 300 m 2 /g), predefined size (from 0.3 to 1.5 μm) and narrow size distribution (σ ranging from 10 to 15 %). However, the freshly obtained TiO 2 XRD-amorphous microspheres are sensitive to the pH value of the media. The additional annealing and the hydrothermal treatment were used for the partial crystallization of TiO 2 . Mechanical properties of individual particles of the initial and treated samples were measured in-situ with the use of the MEMS-based Hysitron PI 95 at Zeiss Libra 200MC TEM. Particles were sedimented on the silicon wedge (1 μm flat-top). Compression tests at constant rates under displacement control and creep tests under constant load were performed to study elastic and viscoplastic properties of the material. The reduced Young’s module was evaluated implying deformation is axially symmetric and its dependence on crystallinity was examined. The values for the individual particles were compared with the properties of the bulk sample obtained by compacting of the same particles. This work was supported by the Lomonosov MSU Program of Development.