Molecular mechanism for the absorption of ketone volatile organic compounds by ionic liquids

With the development of industry, volatile organic compounds (VOCs) have received increasing attention as a class of pollutants that need to be eliminated due to their adverse effects on the environment and human health. As a new green solvent, ionic liquids (ILs) are regarded as the excellent alternative to traditional organic absorbents. To investigate the effect of IL structure on its capture of VOCs, [BMIM][TF2N], [BIM][TF2N], and [EIM] [TF2N] were used as acetone absorbents in this work, and the mechanism was revealed microscopically by quantum chemical calculations in conjunction with the COSMO-RS model. The results suggested that acetone tends to bind to protonic ILs more than the same type of nonprotonic ILs. For protonic ILs, changing the length of the cationic substituent has little effect on the results. Therefore, ILs with short substituent can increase the mass absorption of acetone without essentially changing the mole absorption, thus facilitating the industrial application.