How would you-all recommend cleaning Titanium Dioxide out of glassware?
The TiO2 is adhered to the insides of a small, glass, volumetric flask and also inside the spout portion of a glass funnel. I was diluting a
TitaniumI(IV) Isopropoxide solution with ethanol….but apparently the ethanol was not an anhydrous as I thought and TiO2 precipitated out and got
stuck to the walls of the container..
The TiO2 would easily come off if I could only wipe it clean, but due to its location this is extremely difficult.
I could probably clear out the funnel with a thin pipe-cleaner by jamming it down the spout and effectively wiping away the TiO2, but the volumetric
flask is more difficult due to its long, thin, neck.YT2095 - 15-1-2008 at 11:42
Hydrogen peroxide will help dissolve is in water, but then you must take the ions with something, a Carbonate may help.YT2095 - 15-1-2008 at 11:48
HF will will do it also, but it`ll ruin your glassware if it`s too strong. neutralise with ammonia.mrjeffy321 - 15-1-2008 at 11:56
Hydrogen Peroxide...I never would have thought of that.
Thanks.
Edit:
Ya, I want to stay away from HF to keep from damaging the glassware more than I absolutely need to.
[Edited on 1-15-2008 by mrjeffy321]
[Edited on 1-15-2008 by mrjeffy321]12AX7 - 15-1-2008 at 16:29
Oxalic acid or HCl may produce results.
Timwoelen - 16-1-2008 at 00:12
HCl does not work (personal experience). H2O2 does work, but only on fresh precipitate. It forms a complex with a deep red/orange color (it high
dilution it is yellow).gregxy - 16-1-2008 at 09:41
How about a mixture of sand or fine gravel and water? If you shake it gently it may wear away the film. Just be careful
since it could also scratch the glass.mrjeffy321 - 16-1-2008 at 14:53
The Hydrogen Peroxide worked quite well.
I was using 30% H2O2, since that is what I had available at the time. The TiO2 ‘stains’ were two days old when I cleaned the glassware today.
Using H2O2 by itself and adding it to the TiO2-coated glassware, the clear H2O2 solution turned yellowish-colored immediately.
Using H2O2 in combination with Sodium Carbonate, the solution stayed clear / white. Adding Sodium Carbonate to the already yellowed H2O2 solution
turned it back to clear / white.
Even adding [pure] H2O2 to containers which I thought were clean, but has used for TiO2 previously turned the solution yellow due to trace amounts of
TiO2 present which I didn’t even know were there.
Quote:
Originally posted by gregxy
How about a mixture of sand or fine gravel and water? If you shake it gently it may wear away the film. Just be careful
since it could also scratch the glass.
That idea had occurred to me, but it felt that it would not get the glassware truly clean, it would just remove most of the larger particles, but
leave a thin film behind.12AX7 - 16-1-2008 at 15:10
The peroxy-titanium complex decomposes and precipitates in basic solution (and on drying, what a shame you can't crystallize that red stuff!).
I wonder if H2O2 as a ligand would be valuable to etching titanium, or if H2O2 as an oxidizer would be self-defeating. Hmm...
TimBezaleel - 13-7-2013 at 14:50
I had some TiO2 stuck in a bump trap that had been in there for 2 years. I tried H2O2 that was 36% when new, but I guess it wasn't concentrated enough
anymore to dissolve the TiO2. Only a hint of yellow colour was formed when shaking it in the bump trap.
I sought resort to some 40 ml of 15% HCl solution with a spatula full of NaF, not all of which went into solution. After shaking it for a few minutes,
all TiO2 had been removed from the glassware, and was floating around as small particles. I did notice that the solution had become turbid. I can
hardly believe that this is due to attacking of the glass. I think it may be the result of spreading of the undissolved NaF as very fine particles.
The glassware now looks shiny and not etched.Oscilllator - 15-7-2013 at 23:41
If it can easily be removed mechanically, then I can highly recommend swirling sand in the flask. I do this on a regular basis and to date have not
noticed any scratching on the glassware.Organikum - 25-12-2022 at 18:33
Most metal stains are easily begone with hot oxalic acid.
