Vapor–liquid equilibria in the binary mixtures of N-butylpyridinium hexafluorophophate and bis(trifluoromethanesulfonyl)imide ionic liquids with acetone: Molecular dynamics simulations

Vapor–liquid equilibria of the N-butylpyridinium hexafluorophosphate [BPY][PF6]-acetone and N-butylpyridinium bis(trifluoromethanesulfonyl)imide [BPY][TFSI]-acetone mixtures at 310–350 K were investigated using molecular dynamics (MD) simulations. A detailed analysis of the thermodynamic and dynamics properties is presented. The Raoult's law in conjunction with the van't Hoff parameter suggests a somewhat smaller boiling temperature increase then it is actually observed. The effect of both [BPY][PF6] and [BPY][TFSI] on the acetone phase behavior is similar. Neither free ions nor ion pairs were detected in the vapor phase. Ionic motion at the interface is much less correlated than in the bulk phase. The vapor–liquid interfaces of the investigated mixtures are deemed interesting for the applications of versatile ion-molecular mixtures.

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