Ion Pairing & Ionicity in Ionic Liquids

Room-temperature ionic liquids are pure molten salts — no solvent, just cations and anions packed together — and their conductivity depends on a subtlety that trips up the naive picture: a lot of the ions that are happily diffusing around are doing it as tightly bound, charge-neutral cation–anion pairs that carry no net current. This 2D simulator tracks every individual ion's bound/free state directly: opposite ions that drift within a temperature-dependent capture radius lock into a transient pair and separate again after a temperature-dependent lifetime, exactly the microscopic picture behind real ion-pairing kinetics. The fraction of ions that stay free at any instant — the "ionicity" — is measured live from the actual particle population, and a second panel re-runs the same kinetics at several fixed temperatures simultaneously to trace out a live ionicity-vs-temperature curve, the same trend electrochemists read off a real Walden plot.