Excess entropy scaling of diffusion in room-temperature ionic liquids.
Excess entropy scaling relationships for diffusivity of ions in room-temperature ionic liquids are tested using molecular dynamics simulations for a model ionic liquid, dimethyl imidazolium chloride. The thermodynamic excess entropy of the single ions (estimated from the ion-ion pair correlation functions) is shown to be very strongly correlated with the diffusivity. An essential feature of these systems, the fact that the heavier and larger cation has a greater diffusivity with respect to the anion, is correctly captured by the excess entropy calculations, which estimates the diffusivity ratio between the two ions with noticeable precision.
Malvaldi
Marco
M
Dipartimento di Chimica e Chimica Industriale, Universita di Pisa, Via Risorgimento 35, 56126 Pisa, Italy. marco@dcci.unipi.it
Chiappe
Cinzia
C