Although theoretical work has suggested the absence of an inversion temperature in aqueous solutions at infinite dilution conditions due to a lack of ion-ion interactions, this phenomenon remains underexplored. Here, the authors report phase-shifting interferometry visualisation experiments in alkali halide aqueous solutions and show that thermophobic behaviour becomes more dominant as the solution concentration decreases, and the disappearance of inversion temperatures in ultra-dilute solutions is corroborated by molecular dynamics modelling and an entropy model.
- Shuqi Xu
- Kasimir P. Gregory
- Juan F. Torres