I have a commerical cheap TiO2 white powder with me. I suppose it is amorphous and not nanocrsytalline (as it did not cost me much). I was wondering if this amorphous powder can be converted to nanocrystalline in any way. I do know that heat treatment would make the crystallization possible (around 500-550 deg C for anatase and over 600 deg C for rutile). But how to make them nanocrystalline simultaneously? Mere thermal treatment definitely would not turn it into nanosized powders. Can the amorphous powder be dissolved in something and then recrystallized through sol gel method or some other method to get nanoparticles which can then be later calcined for crystallization?
Rajaraman Ts
By hydrolysis of a solution of titanium sulfate, a mixture of rutile and anatase is obtained. A commercial product, depending on the application, can be pure rutile and anatase, but the particles can be with a wide size distribution. In student work, we obtained nanoparticles by additional dispersion and separation in an aqueous medium. Nanoparticles were selected on top of the cylinder.
In the following article, the nano-crystals of TiO2 were prepared by calcining TiO2 at 500 ° C for 3 h.
http://downloads.hindawi.com/journals/jnm/2011/589185.pdf
Ball milling process can be used which can break the particle size into nanaosize but timing of ball mill should be based on your current commercial size of the material .
Rajaraman Ts , yes, its true that heat treatment will result in crystalline structure but how are you sure that your powder is amorphous? Did you purchase Dagussa D25? Even this commercial powder has crystalline form.
Hi;
Please see the following article:
Effect of Calcination Temperature on Titanium Oxide Nanocrystallites in the Anatase Phase Synthesized By Sol-Gel Route.
With my best regards
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