
376 HIGH PERFORMANCE POLYMERS
H
2
permeability coupled with an ideal H
2
/CO
2
permselectivity.
Ionic liquids supported on porous polymer mem-
branes can enhance the gas separation performance as
this design improves both permeability and selectivity
for a series of industrially relevant gas mixtures [27].
However, at elevated process temperatures the vis-
cosity of the ionic liquid decreases, which is a serious
drawback. To overcome these problems, thermally sta-
ble composite ionic liquid and polymer membranes
have been developed [27].
16.4.3 Fuel Cells
The state of the art of PBI-based polymer electrolyte
membranes for their use in high-temperature fuel cells ...