Effects of membrane thickness and membrane preparation condition on facilitated transport of CO2 through ionomer membrane

Facilitated transport of CO 2 through a thin solution-cast perfluorosulfonic acid ionomer membrane has been studied. The CO 2 carrier was monoprotonated ethylenediamine and was immobilized in the ionomer membrane by electrostatic force. The cast membrane with membrane thickness 22 μm showed much higher CO 2 permeance than the commercial Nafion ® 117 membrane of thickness 186 μm. However, selectivity of CO 2 over N 2 was lower in the cast membrane. The effects of the membrane thickness and annealing temperature in the membrane preparation on membrane performance were investigated. CO 2 permeability and the selectivity decreased with decreasing membrane thickness and with increasing annealing temperature. Dynamic mechanical studies were done to study the membrane structures. The cast membrane annealed at 200°C showed two peaks similar to the commercial membrane. In contrast to this, the peak assigned to the polar region was small in the cast membrane annealed at a lower temperature, which suggested that clear clusters do not form in the membrane.