ИСТИНА

Titania microspheres are the perspective object for the fabrication of high performance liquid chromatography columns. The usual material for this application are silica microspheres of ⌀1-10 µm. The proposed method of Ti(nBuO)4 controlled hydrolysis allows one to obtain titania microspheres with high specific surface area , predefined size and narrow size distribution. Initially amorphous particles present an opportunity to obtain materials with dissimilar crystallinity by choosing the appropriate treatments. Following treatments were used for partial crystallization of particles: annealing at 400°C, annealing at 700°C, hydrothermal treatment (HT), hydrothermal treatment with subsequent annealing at 400°C. Mechanical properties of the individual particles from the untreated 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) by dry coating. Compression tests at constant rates under displacement and load control as well as cyclic loading with partial unloading were performed. Observation of the indentation processes were performed in HAADF-STEM mode, corresponding video data were acquired.