Ionic liquid modified poly(2,6-dimethyl-1,4-phenylene oxide) for CO2 separation

Ionic liquid modified poly(2, 6-dimethyl-1, 4-phenylene oxide) (PPO) was synthesized by introducing imidazolium-based, pyridinium-based, and ammonium-basd ionic liquid groups to the methyl position of PPO. Membranes were prepared from the different types of ionic liquid modified PPO (IPPO), and the permeability of CO and N2 in these membranes was characterized. For having the CO -philic ionic liquid groups in the structure, the CO solubility of the IPPO is better than that of PPO, while the CO diffusivity in the IPPO is proportional to glass transition temperatures. The adsorption and desorption of CO in the IPPO were also investigated, and the results manifest that the adsorption and desorption of CO in IPPO are completely reversible, which makes the polymer promising as solid adsorbent materials for CO separation