Herein we report the chemotactic behaviour of self-propelled droplets
composed solely of the ionic liquid trihexyl(tetradecyl)phosphonium
chloride ([P6,6,6,14][Cl]). These droplets spontaneously move along an
aqueous-air boundary in the direction of chloride gradients to specific
destinations due to asymmetric release of [P6,6,6,14]
+ cationic surfactant
from the droplet into the aqueous phase.