Adsorbed media and their molecular sizes
-
Molecule
Molecule critical diameter, A
Molecule length, A
Hydrocarbons
Methane
3.8
–
Ethane
4.0
4.6
Propane
4.9
6.52
n-Butane
4.9
7.78
n-Pentane
4.9
9.04
n-Hexane
4.9
10.34
n-Heptane
4.9
11.5
Other normal paraffins
4.9
Neopentane
7.0
7.08
Ethylene
4.0
4.6
Propylene
4.0
6.5
Buten-1
4.9
5.6
Buten-2
4.9
–
1,3-Butadiene
5.2
–
Cyclopropane
4.9
Cyclohexane
6.1
–
Acetylene
2.4
Benzol
6.0
5.7
Toluene
6.7
–
o-Xylol
6.0-7.4
–
n-Xylol
6.5-6.8
–
Thiophene
5.3
–
Isobutane
5.6
Isopentane
5.6
Acetylene
2.4
Industrial gas components
Hydrogen
2.4
3.1
Oxygen
3.4
3.9
Nitrogen
3.7
4.1
Carbon disulfide
3.7
–
Nitrous-nitric oxide
5.0
–
Ammonia
3.6
–
Carbon oxide
2.8
4.1
COS
2.7
Water
2.7
3.2
Carbon dioxide
3.1
4.1
Acidic organic materials
Methyl alcohol
4.0
–
Ethyl alcohol
4.7
5.9
Butyl alcohol
5.8
–
Acetic acid
5.1
Ethyl ester
5.1
Diethyl alcohol
5.1
–
Acetaldehyde
4.4
–
Ethylene oxide
4.2
–
Halogenous media
Bromine
3.9
Iodine
4.3
CHCl3
6.9
CF4
5.5
CCl4
6.9
7.1
CBr4
7.5
7.7
C(CH3)4
6.9
7.1
C2F6
5.3
C2Cl6
6.9
CF3Cl
4.9
CF3Cl2
4.9
CF3H
4.8
CF2ClH
4.9
Rare gases
Helium
2.0
Neon
3.2
Argon
3.8
Krypton
3.9
Xenon
4.4
Other media
Tetramethylmethane
6.8
7.0
1,3,5-triethylbenzol
8.2
Diperflourethylpropylamine
8.7
–
Tripropylamine
9.1
–
Hexaethylbenzol
10.0
–
Triperflourbutylamine
11.5
–
Triphenilmethanol
14.0