From: email@example.com (Gerald L. Hurst)
Subject: Re: Smoke Bomb in glass ?
Date: 17 Jan 1996 15:43:17 GMT
In article <ftn_18.104.22.168_13eb1ea9_Sweden@synchron.ct.se>,
firstname.lastname@example.org (Sweden) says:
> >I have no idea whether butane and TiCl4 are mutually miscable, or whether
> >there are any bad side effects to mixing them. The resulting smoke is
> >not pleasant (due to the Hydrochloric Acid), but TiCl4 has been used
> >in commercial smoke preparation (ie skywriting.)
> GLH> It would be surprising (to me) if they were not miscible. The
> GLH> TiCl4 is a low polarity liquid (symetrical tetrahedral bonds).
> GLH> Because it can also coordinate, it would probably dissolve in
> GLH> a wider range of solvents than most materials. I love to
> GLH> speculate. I trust that somebody who KNOWS will confirm or
> GLH> deny.
>I don't have the correct answer, but can imply that TiCl4 is very
>corrosive! It eats right through condoms, so glass containers
>might be a good choice. Plastic and metal should be tested before
>actual use. TiCl4 can be absorbed by kiselguhr and spread by means
>of a detonation. The smoke is very dense and unhealthy. Keep TiCl4
>away from all moisture, or it will hydrolyse instantly (even in
>moist air). TiCl4 is very expensive if pure. I haven't been able to
>find a cheap sorce.
I've worked with TiCl4. It does not really hydrolyze instantly,
although it does fume. In water you can get intermediate oxychloride
species before hydrolysis is complete. TiCl4 can be dissolved
in cold water but reacts rapidly at increased temperatures.
The hydrolysis reaction is used commercially to manufacture TiO2
in fine particulate form. When the particle size is optimized at
about 0.3 microns, the very high refractive index of TiO2 results
in correspondingly high hiding power or whiteness, exceeding even
that of diamond dust. This hiding power make the material
particularly useful as a white paint pigment. The same principle
applies to smoke.
For most effective smoke use a binary system with ammonia can be
used. Simultaneous release of ammonia and TiCl4 gives the following
double smoke reaction:
TiCl4 + H2O --> TiO2 + 4HCl (smoke +1)
HCl + NH3 --> NH4Cl (smoke #2)