(679d) Spectroscopic Observation of CO2 Absorption Behavior of Nanoparticle Ionic Materials

Ionic liquids, a molten salt composed of cations and anions, have received much attention due to their various physicochemical properties such as low melting point, low combustibility, non-volatility, excellent thermal stability, and solvating property, which allow them to be applied to various energy and environmental processes. Because ionic liquids could easily be modified by numerous combinations of cations coupled with anions, they possess tunable properties to meet the specific needs; for example, as potential green solvents and electrolytes. Recently, many researchers are investigating ionic liquids as novel CO2 capture medium. Compared to the conventional amine-based solvents (e.g., monoethnolamine (MEA)), which often suffer from corrosion and vaporization/degradation loss, ionic liquids exhibit reversible CO2 absorption and desorption without environmental problems because of its immeasurable vapor pressure. Therefore, ionic liquids have been suggested as an alternative option for CO2 capture technology.

In this study, we are focused on the newly synthesized ionic materials called Nanoparticle Ionic Materials (NIMS), which are nanoscale analogs of ionic liquids. NIMS consist of inorganic nano-sized cores and amine-functionalized corona. By tuning its functional groups as well as the volume fraction of nanoparticles, NIMS can be designed for the efficient CO2 capture with great flexibility for the counterion species. CO2 absorption and desorption behavior of NIMS are investigated through spectroscopic observation by employing IR and Raman spectroscopy. The results are compared with those of conventional and task-specific ionic liquids. The findings of this study would offer deeper understanding of CO2 absorption and desorption mechanisms of NIMS under various operating conditions.