Investigation of the CO₂-solubility in deep eutectic solvents using COSMO-RS and molecular dynamics methods

In this work, the theoretical solubility of CO₂ into different choline chloride and phosphonium based deep eutectic solvents (DESs) was successfully calculated using COSMO-RS method. FTIR spectrums of the seven DESs were calculated in order to investigate and check out their structure. There was a good agreement between the predicted values and the experimental results reported in the literature. The Sigma profiles analysis showed the possibility of formation of H-bonding between CO₂ and the DESs which favors increasing the solubility of CO₂. Molecular dynamics simulation was performed to investigate the molecular interaction between the different DESs and CO₂. The actual approach can be used in the estimation of different physicochemical properties of DESs especially the capture of undesirable molecules like H₂S, NOx, H₂O and CO₂.