Modeling Control over the Size and Phase Composition of Submicron Particles of Titanium Dioxide Synthesized in a Flow Plasma-Chemical Reactor

A mathematical and experimental modeling of the process of synthesis under nonequilibrium conditions of a fine powder of titanium dioxide anatase crystalline modification with a combination of reaction zones and counter hardening has been carried out. The formation of ultrafine particles occurs in regions with large values of the convective derivative of temperature (similar to 10(5) K/s). The mass-average particle size was 10-70 nm in calculations and 32-45 nm in experiments. The anatase content of the powder in calculations was 70-90% and in experiments similar to 83%. This method allows control over the phase composition and particle size of the synthesized titanium dioxide powder used as photocatalysts, in particular, when treating wastewater from organic waste and air from harmful impurities.