“…Moreover, when ILs were used to capture CO 2 or SO 2 from flue gas with a certain amount of water, they might absorb water from flue gas due to their hydrophilicity [17,18]. For example, the effect of moisture on CO 2 absorption of 1,1,3, 3-tetramethylguanidine imidazolide ([HTMG] [IM]) was investigated in our previous work [14], and the results showed that moisture of the CO 2 could affect the absorption of [HTMG]IM, especially at the beginning of CO 2 increasing of the moisture of CO 2 . Therefore, it is necessary to know the thermophysical properties of binary mixtures of ILs with water, such as density and viscosity, which are very important basic data for ILs during the practical application.…”