Investigation on dispersion properties of CO(2) and ester solvent mixtures using in situ FTIR spectroscopy

To study the microscopic dispersion state of CO(2) in different ester solvents, the solubility, volume expansion coefficients and in situ Fourier transform infrared (FTIR) spectra of the CO(2)–ester system were measured. The results show that the solubility and expansion coefficient of CO(2) in ester solvents decreases as the hydrocarbon chain increases. As the pressure increases, the infrared absorption peaks of CO(2) and the functional groups characteristic of ester molecules shift, indicating that CO(2) molecules interact with ester molecules and that CO(2) would destroy the interactions between the ester molecules. The hydrocarbon chain length of the ester molecules has a significant effect on the infrared absorption peak of the CO(2)–ester system. As the hydrocarbon chain length increases, the CO(2) absorption peak shift and peak shift of the carbonyl groups in the ester gradually decrease.