Rayleigh limit

https://doi.org/10.1351/goldbook.12545
Limiting droplet size at which self-fragmentation will occur for charged droplets generated in electrospray or other ionization processes. Self-fragmentation occurs when the electrostatic repulsion force generated by the excess charge exceeds the surface tension that maintains the integrity of the droplet.
Source:
PAC, 2013, 85, 1515. (Definitions of terms relating to mass spectrometry (IUPAC Recommendations 2013)) on page 1583 [Terms] [Paper]