These ILs exhibit low viscosities (34 mPa s [16] and 22 mPa s
[17], respectively, at 298.15 K) and due to their low molecular
masses (208.31 g mol1 and 169.25 g mol1, respectively) their
heat capacities should be also relatively low (439 J K1 mol1 and
259 J K1 mol1, respectively, at 298.15 K, as estimated by method
of Farahani et al. [18]). As indicated by previous measurements of
infinite dilution activity coefficients of ours [19] for [BMPYR][DCA]
and Domanska and Marciniak [20] for [EMIM][SCN], these ILs show
a very strong affinity to methanol, while their interactions with aliphatic
hydrocarbons are quite unfavorable, which forms the basis
for their separation selectivity. The selectivities of the present ILs
for methyl acetate/methanol separation are expected to be high
and exceed those for the ILs studied in the literature, which can
be inferred from their infinite dilution values b1
12 (323.15 K)
obtained either from direct measurements of limiting activity
coefficients ([BMPYR][DCA]: b1
12 ¼ 4:45) [19] or estimated by the
ion-specific Abraham solvation model [21] ([EMIM][SCN]: b1
12 ¼
6:7, [EMIM][OTF]: b1
12 ¼ 1:4, [OMIM][PF6]: b1
21 ¼ 1/b1
12 ¼ 1:9).