Quantitative investigation on the physical and chemical interactions between CO2 and amine-functionalized ionic liquid [aEMMIM][BF4] by NMR

- The existence of both physical and chemical interactions between [aEMMIM][BF4] and CO2 was verified.
- A method to estimate the ratio of physical and chemical interactions between [aEMMIM][BF4] and CO2 based on NMR spectra was proposed.
- The chemical interaction mechanism of [aEMMIM][BF4] and CO2 was proved to 1:1 stoichiometry by NMR and DFT calculations.
- Tethering high sterically substitute group at IL helps to obtain an equimolar CO2 absorption.