Relation between enthelpy of sublimation and rate of sublimation?

Click For Summary
The discussion centers on determining the sublimation rate of UO2+x under high-vacuum conditions during extended heating. The user seeks to calculate sublimation rates based on saturated vapor pressure, which is not available for this material, although enthalpy of sublimation has been published. There is currently no established relationship between enthalpy of sublimation and sublimation rate or saturated vapor pressure. The inquiry highlights a gap in available data for accurate modeling. Ultimately, the conclusion is that no direct correlation exists.
DenisH
Messages
3
Reaction score
1
TL;DR
Is there a way to get the rate of sublimation of a material in vacuum for a given temperature from its enthalpy of sublimation?
Hello,
I am running experiments where materials are heated at high temperatures during tens of hours under high-vacuum conditions. Since what I am investigating lies in the first hundreds of nanometers of the materials, I must take into account (and anticipate) surface sublimation.
Therefore I am trying to determine at which rate a sample surface is sublimating. I found that this can be calculated from saturated vapor pressure, giving results in consistent with my experimental observations. Unfortunately for the material I am working on (UO2+x), no such saturated vapor pressure has ever been published... but enthalpy of sublimation had been.
At this stage I did not found a relation between enthalpy of sublimation and sublimation rate (or saturated vapor pressure)... my question thus is: is there one?
Thank you
 
Engineering news on Phys.org
DenisH said:
Summary:: Is there a way to get the rate of sublimation of a material in vacuum for a given temperature from its enthalpy of sublimation?

my question thus is: is there one?
No.
 
Somewhat separate from the coffee advice of “buy whole beans, grind fresh at home daily”, I'm looking to understand the factors that contribute to purchased ground coffee losing freshness after opening (oxygen, humidity, temperature, time, other?). I'm assuming oxidation is the main factor, assuming normal room temperature and mid-range humidity. It appears (I'm having trouble finding good info on this) that a high quality modern pre-ground coffee is packaged in a way that maintains...

Similar threads

Replies
3
Views
4K
  • · Replies 3 ·
Replies
3
Views
5K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 5 ·
Replies
5
Views
4K
  • · Replies 11 ·
Replies
11
Views
4K
  • · Replies 6 ·
Replies
6
Views
12K
Replies
11
Views
9K
  • · Replies 3 ·
Replies
3
Views
3K