I am trying to determine if organic solids that are rapidly heated (to ~200C) eject both solid and liquid droplets during the heating/melting process. A colleague of mine has studied explosives and is pretty sure they only saw liquids, but collections of my volatilized samples show liquid and solids. Is this the result of solid particles being ejected from the heated sample? Or liquids recrystallizing upon cooling? Any help is appreciated!
This depends at least in part on the mass, granularity, and uniformity of the solid. If granules are put on a hot surface transition to the gas phase can eject overlying solids.
If you have uniform volatilization, then condensation aerosols will form, and may or may not crystallize..
See, for exmple, the levitation melted metal http://yandex.ua/video/search?text=%D0%BB%D0%B5%D0%B2%D0%B8%D1%82%D0%B0%D1%86%D0%B8%D0%BE%D0%BD%D0%BD%D0%B0%D1%8F%20%D0%BF%D0%BB%D0%B0%D0%B2%D0%BA%D0%B0%20%D1%81%D0%B2%D0%BE%D0%B8%D0%BC%D0%B8%20%D1%80%D1%83%D0%BA%D0%B0%D0%BC%D0%B8&path=wizard&filmId=8amHCuf6UXI
This is an effective method for generation of nanoparticles. It was realized in (see attached file)
As described by Ronald W. Wood, there are a lot of dependencies and both is possible - including gas-to-particle-conversion under some circumstances. Maybe it is possible to see the differences "cold droplets --> solid" and "re-crystallization" under a REM.
Otherwise it can be usefull, to heat the probe-pipes including filters. You will find some hints under the subject "particle measurements and hot gases" or "condensation effects".
Thank you all for your answers. I am heating a small solid residue remaining after solvent evaporation. This is passively collected, not with an impactor, and I can see what looks like both solid particles similar to the crystalline powders and more droplet-like features. Are these both normal?