Abstract
Amidoxime-functionalized polydimethylsiloxane (AO-PDMSPNB) membranes with various amidoxime compo-
sitions were synthesized via ring-opening metathesis polymerization followed by post-polymerization
modifica- tion. Compared to other previously reported PDMS-based membranes, the amidoxime-functionalized mem- branes show enhanced CO2 permeability and CO2/N2 selectivity. The
overall gas separation performance (CO2 permeability 6800 Barrer; CO2/N2 selectivity 19) of the
highest performing membrane exceeds the Robeson upper bound line, and the excellent permeability of
the copolymer itself provides great potential for real world applications where huge volumes of
gases are separated. This paper details how tuning the CO2-philicity within rubbery polymer
matrices influences gas transport properties. Key parameters for tuning gas transport properties are
discussed, and the experimental results show good consistency with theoretical calculations.
This study provides a roadmap to enhancing gas separation performance in rubbery polymers by tuning
gas solubility selectivity.
