Chemistry Reference
In-Depth Information
Type I
Type II
Type III
V
ads
p
p
0
p
0
p
0
V
ads
Type IV
Type V
p
p
0
p
0
Figure 10.4.
Basic adsorption isotherm shapes for vapors on solids below critical
temperature T
c
of the adsorbate.
represent monolayer adsorption of gas onto the solid surface, although it is was sub-
sequently realized that microporous adsorbents will produce similar isotherms. The
remaining isotherms (II-V) represent various processes of multilayer adsorption.
Although most adsorption isotherms fall into two main categories, many subtle
and not so subtle shape variations have been reported, leading to a more complex
classification system as illustrated in Figure 10.5. That classification system gives
L
S
H
C
1
2
3
4
Figure 10.5.
Adsorption isotherm classifications covering greater concentrations of adsorbate.
