Nucleation of solution convection channels as the first step in electro-hydrodynamic pattern formation

The evolution of luminescent electrohydrodynamic (EHD) convection patterns is observed in thin layer electrochemical cells. The applied cell voltage is found to initiate a nucleation-type process in which autonomous convection channels form between the electrodes. With progressing time, more channels of the same type along with irregularly shaped arrangements of such channels are detected. Within a period of seconds, the system undergoes a transition from the disordered into an ordered state. Thereby, the well-known cellular EHD convection structures emerge. However it appears that even in the stationary patterns the individual convection channels remain intact, constituting well discernible flow structures.