Membrane Gas Separation

7.5
Conclusions 
Mixed matrix membranes based on fl uorinated high free volume matrices loaded with 
fumed silica nanoparticles show attractive features, especially if compared to unloaded 
polymeric membranes. The addition of fi ller changes the FFV of the glassy polymeric 
matrix, thus positively affecting both solubility and diffusivity. A simple procedure has 
been proposed to calculate the relevant properties of the MMM, which is based on limited 
experimental data represented by the solubility isotherm of a test penetrant and few values 
of diffusion coeffi cients. The unexpected behaviour shown by the MMM obtained by 
using nano - fi ller loadings can be properly described by the method developed. The 
(a) 
10
100
1000
10
4
0
20000
40000
60000
80000
100000
Teflon AF2400
Teflon AF2400 + 25% FS
Teflon AF2400 + 40% FS
Permeability (Barrer)
Pressure (Pa)
(b)
10
100
1000
10
4
10
5
0
10000
20000
30000
40000
50000
60000
Teflon AF2400
Teflon AF2400 + 25% FS
Teflon AF2400 + 40% FS
Permeability (Barrer)
Pressure (Pa)
(c)
1
10
100
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
n-C
4
in AF 2400
n-C
5
in AF 2400
P
0
M
/P
0
P
w
F
/(1-
w
F