Electrical breakdown phenomena at the surface and within liquids

Breakdown phenomena in liquid water is the basis of a myriad of potentially promising applications ranging from water purification to nanoparticle formation. Initiation of the discharge typically occurs over short time scales with subsequent plasma generated species, diffusion and thermal effects occurring over longer times. Such modifications and changes in local chemistry at the surface and within the liquid effects the nature of subsequent breakdowns as the liquid locally evolves over time. Underpinning such breakdown phenomena is the propagation of ionization wave phenomena at the surface and within the volume of the liquid. These processes remain not well understood. Here we review breakdown phenomena at the surface and within dielectric liquids with particular emphasis on water. Computational models and complementary experiments both past and present elucidating breakdown in liquids are discussed, painting the picture of our current understanding of this fascinating process.