Nanostructured ZrO2 Synthesized by Using Pressurized and Supercritical Fluids — Its Structural and Microstructural Evolution and Thermal Stability.

0475188 - ÚCHP 2018 RIV NL eng J - Journal Article
Matějová, Lenka - Matěj, Z.
Nanostructured ZrO2 Synthesized by Using Pressurized and Supercritical Fluids — Its Structural and Microstructural Evolution and Thermal Stability.
Journal of Supercritical Fluids. Roč. 128, OCT 2017 (2017), s. 182-193. ISSN 0896-8446. E-ISSN 1872-8162
R&D Projects: GA ČR GA14-23274S
Institutional support: RVO:67985858
Keywords : zirconia * microstructure * crystallization
OECD category: Inorganic and nuclear chemistry
Impact factor: 3.122, year: 2017

Nanostructured ZrO2 was successfully prepared by processing by pressurized hot water and pressurized hot/supercritical methanol in a flow regime. Processing temperature and amount of used water are crucial for ZrO2 crystallization. Processing by pressurized hot or supercritical methanol improved ZrO2 purity and affected microporosity, but did not cause ZrO2 crystallization. The effect of processing pressure on ZrO2 crystallization was also proved, at 10 and 30 MPa the crystallization of zirconia was enhanced. Processing by both pressurized fluids at different conditions has significant impact on further crystallization of ZrO2 during post-thermal treatment, thus, the phase composition of ZrO2 can be tailored. While thermal treatment of nanocrystalline ZrO2 led to crystallization of bicrystalline ZrO2 mixture with major monoclinic phase, thermal treatment of amorphous ZrO2 resulted in crystallization of bicrystalline ZrO2 mixture with major tetragonal phase.
Permanent Link: http://hdl.handle.net/11104/0272163