Recently, I tried to gather soot (carbon black) at slide glass through alcohol lamp burning. The glass was positioned over flame of wick (about 5 cm from the wick). Under amorphous glass condition, it could not endure high temperature of flame. Although it barely endured the flame and the soot was deposited at the glass, the soot was easily escaped the glass by little breeze. So I replaced the amorphous glass with a quartz glass for standing heat. The soot was collected at quartz glass and it showed little enhancement of adhesion on the quartz glass (Not escaped by little breeze !).
So I have two questions,
1) Why soot is more adhesive at the quartz surface than amorphous glass surface?? Some paper recommended that the soot could be collected at the quartz surface or Si wafer. Is there any profound mechanism on it?
2) Is there more convincing way to adhere soot at the surface (substrate)?
Plz give a kind answer for me!! :)
It must have something with either the roughness of your amorphous glass or the bonding. I think it's the first case,check the roughness difference between the quartz and amorphous glass. It also might have something to do with the conditions of creating the soot i.e. how much air exposure is allowed, or the distance. A former colleague of mine did some interesting study on this topic, see below:
http://www.sciencedirect.com/science/article/pii/S0169433216302586
GL
Common glass types are typically richer in surface polar groups (such as silanol), what imparts higher energy character to their (clean) surfaces; compared with quartz glass (fused silica). Such difference even tends to be enhanced by the effect of heat, due to humidity loss. Hence, we can expect higher adsorption capacity for the quartz glass surface ― compared with common glass ― toward substances characterized by non-polar (hydrophobic) molecular forces, such as those from the molecules that constitute soot, which has hydrophobic character. The fact that surface roughness is typically higher for quartz glass also facilitates soot adsorption. Being combustion a rather complex issue, other possible factors, such as heat transfer profiles, which can not be exactly matched when one glass type substitutes for the other, may also contribute.
Ohh thanks a lot, I found some clues thanks to both of your comments !!
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