Physical aging of ultrathin glassy polymer films tracked by gas permeability

Membrane technologies for CO2 capture

“…In addition, also the occurrence of flooding and entrainment of the absorption liquid may occur and limits the process as the gas and the liquid streams cannot be controlled independently [22][23][24][25].…”

“…Wetting of the porous membrane is a serious problem as it significantly increases the resistance to mass transfer through the introduction of a stagnant liquid layer in the pores of the membrane [13,24]. A method proposed to overcome this limitation is the use of hydrophobic porous membranes when hydrophilic absorption liquids are used, but especially the long term effect can be limited.…”

“…In the present work, we combine the high product yields and selectivities of absorption processes [14] with the advantages of membrane technology in a membrane contactor for the separation of CO 2 from CH 4 ( Figure 1) using amino acid salt solutions as competitive absorption liquid to alkanol amine solutions. The membrane in the contactor has no selectivity but only a contacting function and it separates the gas flow on one side and the absorption liquid on the other side of the membrane [24]. CO 2 diffuses from the gas side through the membrane and is selectively absorbed by the absorption 4 Sweep gas Absorbent Circular flow…”

“…Changes in film thickness however can generate changes in membrane performances [11]. CO 2 sorption and plasticization phenomena in thin films can be distinctively different from sorption in bulk materials [11,24]. Kim et al [25] showed for glassy 6FDA-based polyimide films that the aging rate is greatly accelerated for thin films compared to thick bulk films and that a correlation of aging rate to free volume is expected.…”

“…Tight arrangements between the oppositely charged ionic domains present in the poly(RTIL) may have the potential to prevent the membrane from excessive swelling and deterioration of its performance at increased pressure and/or temperature. Wang et al [24,25] systematically investigated the gas transport properties of various poly(aryl ether ketone)s and observed an increased gas selectivity at the expense of the permeability in polymers with stronger ionic interactions.…”