| 초록 |
We report a distinct behavior of water in the forming of a reversible complex with CO2, when water is coordinated to alkali metallic cation such as Li+, Na+ and K+, called a cationic bound water, but unexpectedly no CO2 complex with the anionic bound water for CF3CO2-. In particular, the cationic bound water of K+ shows the best activity for the reversible complexation with CO2, offering an additional transport pathway of CO2, as demonstrated via NMR spectroscopy for the first time. These findings have been applied to the polymeric membrane material development for capturing CO2 from flue gases. Poly(ethylene oxide)-based membrane showed super-permeable characteristics for CO2 only (the CO2 permeance of 4,650 gpu (1 gpu = 1 x 10-6 cm3(STP)/cm2 sec cmHg) and the ideal separation factor for CO2/N2 of 1,500) in humid environment, far above the upper bound curve, with negligible performance change up to 6 months. |
