Micromeritics Gemini VII 2390a, Руководство оператора

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Gemini VII Appendix C
239-42828-01 - Dec 2012 C-35
Freundlich Isotherm
Q
Q
m
-------
CP
1/
m
=
Q Q
m
CP
1/
m
=
Q
log
Q
m
C
1
m
----
P
log + log =
The Freundlich isotherm has the form:
where
Q = quantity of gas adsorbed
Q
m
= quantity of gas in a monolayer
C = temperature-dependent constant
m = temperature-dependent constant
The pressure is absolute; typically, m > 1. In terms of quantity adsorbed,
Taking the log of both sides yields:
Temkin Isotherm
Q
Q
m
-------
RT
q
0

---------
A
0
P
 
ln =
Q
RTQ
S
q
0

--------------
A
0
P
Po
-------
 
 
ln + ln =
The Temkin isotherm has the form,
where
Q = quantity of gas adsorbed
Q
m
= quantity of gas in a monolayer
q
0
= the differential heat of adsorption at zero surface coverage
A = a
0
exp {-q
0
/RT}, where

0
and a
0
are adjustable constants
In terms of quantity adsorbed,
Thus, the plot of the natural log of absolute pressure vs. quantity adsorbed yields a straight line with
slope RTQ
m
/q
0
and intercept (ln A) RTQ
m
/q
0

.