QUOTE (belleraphon1 @ Aug 26 2009, 01:46 PM)
And knowing how all these materials really behave under cryogenic conditions.... over eons. Only way to really know for sure is to go there
Low temperature = long reaction time. (tough to get over those energy barrier mouintains with only a moped)
Most of the chemical reactions I'm used to dealing with don't happen at all much below -78 C (dry ice/acetone temperature) or 195 K. That is still 100 K above a balmy afternoon on Titan.
So the low temperatures would effectively insulate the molecules from further reaction. There might be all sorts of exotic things just waiting to react, if only they had a little push...or a long enough time...
So the low temperature + long reaction time (a few billion years) would imply that the low barrier reactions would eventually make it over.
[It'd be a neat exercise to calculate the time difference for a standard reaction between 95 K and 298 K. Someone must've done this somewhere...]
Ahh but what happens during impact events when the local temperature rises to "molten" levels? These would be episodic events, but likely when Titan chemistry would be more Earth-normal.
So...funky atmospheric chemistry making fragile weird molecules that don't do much most of the time, then an episodic reaction cycle during an impact that locally makes chemistry closer to "cold Earth normal stuff), then back to the deep-freeze of accumulating bizarro atmospheric products again.
That's what I'd predict on a molecular level, on an interaction level (surface interactions between molecules) it could be even wierder. Many of the "weaker" interactions on Earth could be relatively strong on Titan. Things like dispersion interactions, pi-stacking, stuff like that. Hydrogen bonds (relatively weak on Earth), could be hard as nails at Titan's low energy. (A 3 kcal H-bond could be a pretty tough barrier at 95 K, not so tough at 298 K). All those dispersion interactions (formerly known as Van der Waals inteactions) could make the molecules sticky at low temperatures. The sticky energy factors would be much higher than the molecular rebound factor (lower kinetic energy = slooooow moving molecules that don't bounce so much).
-Mike