Fundamentals

Thermoynamics is the science of interaction between material and matter:

It describes how adding/removing heat or changing the chemical environment (adding/removing a solvent) changes the properties of a mixture.

Example:

Adding heat to water will evaporate it

Adding water to salt will dissolve it

Applications:

Separation of mixtures is generally based on one of the two following phenomena:

Evaporation: heating a mixture will make that the individual components will evaporate to a different degree depending on their respective volatilities
Solvation: Adding a solvent to a mixture will attract the compounds that have the highest affinity for the solvent towards this product

Activity:

The reactivity of a compound depends on temperature, but also on its surrounding

Electrolytes are species that tend to loose or gain electrons when dissolved into a solvent (typically with a large dielectric constant, as water).

Consequences of this phenomenon are large:

Strong solubility in the solvent
Strong reactivity of the compound (formation of chemical complexes)
The activity (tendency to react) of the compound is strongly affected (e.g. corrosion…)

Electrolyte thermodynamics is sometimes considered as a very complex topic. Here are some videos to help.

First, an introduction that describes the project and an example of challenge

In this second video, some definitions are put in perspective.