International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The investigation of influence of modified conditions on formation of complex materials based on tetragonal zirconia doped by d-elements of I group (Cu or Ag) was carried out, in particular the routes of synthesis and type of dopant. The kinetic parameters of separated stage of NPs formation (drying of hydrogel under MW irradiation, dehydration and crystallization of amorphous zirconia NPs) were estimated. It was shown, the dehydration of tetragonal zirconia hydrogel in conditions of MW irradiation occurs due in two stage. In contrast for Cu (or Ag) –modified hydrogels only one stage dehydration is observed. The dehydration and crystallization of unmodified and modified xerogel is studied by DSC method. It was shown that the kinetic parameters of dehydration depend as from nature of zirconium salts that were using for synthesis and type of dopant. For crystallization processes the some parameters (crystallization temperature, enthalpy) are saved features of dependence on route of synthesis for unmodified and modified systems. However, the behaviour of dependence of activation energy on route of synthesis is contrast for unmodified and modified systems.

The catalytic activity of material was tested by ESR spectroscopy and investigation of the formation of the super-anion radicals of oxygen on surface zirconia particles in dependence on dopant amount, pressure. UV-visible spectroscopy was used for estimation of optical properties of these materials. It was found the introduction of Y2O3 allows to creation of structure defects in partially stabilized zirconia, and its influence for tetragonal crystals is not monotonic in range 2-4 mol. %. It is connected with boundary of stable tetragonal phase at Y2O3 adding. The pressure is active factor of changing of surface state due to tetragonal – monoclinic transformation and may be used for improvements of catalytic properties of zirconia NPs.