pK_a-Dependent Facilitated Transport of CO₂ across Hyperthin Polyelectrolyte Multilayers

Hyperthin (ca. 20–30 nm thick) polyelectrolyte multilayers have been fabricated that are capable of facilitated transport of CO 2 . These membranes were fabricated from polycations bearing pendant groups of varying basicity plus poly(sodium 4-styrenesulfonate) as a polycounterion. A strong dependency of such transport on the basicity of the pendant groups (i.e., fixed carrier sites) has been found, where p K a values in the range of ca. 5–7 appear optimal.