Time-resolved high-speed camera observation of electrospray

A high-speed camera was implemented to visualize the time-resolved fine structure of electrospray of deionized water. This method provided useful visual information on how electrospray initiates, develops and produces water droplets of different sizes. The behavior of different spray mode and its characteristic time-scale were measured. The cone-jet mode subdivided into oscillating cone-jet, rotating cone-jet, stable cone-jet, and unstable cone-jet according to the motion and stability of cone-jet. The size of nozzle also influenced the spray mode. The stable cone-jet mode appeared over a wide range of voltage as the nozzle diameter increased. The hydrodynamic behavior of meniscus or cone-jet played a key role in determining the size of the droplets. Hydrodynamic force induced by vigorous lashing and swirling movement at the jet front was found to play a dominant role in the continuous formation of fine droplets in the cone-jet mode.

Graphical AbstractSnapshots of electrospray in stable cone-jet mode; exposure time was 1/400 s (left, digital camera) and 1 μs (right, high-speed camera).Figure optionsDownload high-quality image (129 K)Download as PowerPoint slideResearch highlights
► High-speed camera observation of electrospray of deionized water.
► Time-resolved evolution of each spray mode.
► The hydrodynamic behavior of cone-jet determines the size of droplets.
► The transition of cone-jet mode from oscillation, rotation to stable cone-jet.