Spheroidization of inorganic compounds by the LPPS method

0487182 - ÚFP 2018 SK eng A - Abstrakt
Mastný, L. - Brožek, Vlastimil - Medřický, Jan - Marek, I.
Spheroidization of inorganic compounds by the LPPS method.
ChemZi. Roč. 13, č. 1 (2017), s. 162. ISSN 1336-7242.
[Zjazd chemikov /69./. 11.09.2017-15.09.2017, Vysoké Tatry, Starý Smokovec]
Grant CEP: GA ČR GA15-12145S
Institucionální podpora: RVO:61389021
Klíčová slova: Water stabilized plasma * Liquid precursor plasma spraying * nanoparticles * spheroidization
Obor OECD: Fluids and plasma physics (including surface physics)

In this study, preparation of spheroidized inorganic compounds by Liquid Precursor Plasma Spraying (LPPS) method is presented. The LPPS method uses inorganic precursors in liquid form which are injected into the plasma where thermal decomposition of the precursors occurs and new materials can be synthesized. The WSP-H plasma torch, developed at IPP Prague, is used as a source of high enthalpy plasma. The WSP-H can reach power of 160 kW, plasma temperature up to 30000 K and plasma outlet velocity up to 4000/s. The precursors are injected into the hot plasma where the stream of liquid is rapidly fragmented to small droplets following the Weber and Ohnesorge criteria. Afterwards, the liquid is evaporated and new material crystallizes, immediately being melted and spheroidized. The spheroidized particles can be then collected in a tank filled with water or liquid nitrogen. When the concentration of the precursor solution is less than 5 wt%, particles with diameter lower than 100 nm are formed. Spheroidized nanometric compounds were successfully prepared LPPS of solutions of nitrate, chloride and chromium salts. The final materials, in a form of spinelsites, ferrites or even superconductive YBaCu-123 were characterised by photon correlation spectroscopy and L*a*b* spectrum.
Trvalý link: http://hdl.handle.net/11104/0281866