How a mass-transfer balance controls surfactant-enhanced boiling*

Boiling is ubiquitous and improvements to boiling performance are challenging due to the unpredictable nature of bubble behavior. One way to improve boiling is through surfactants, which alter the solid-liquid and liquid-vapor interfacial properties of water. Previous studies have found that heat transfer enhancement increases with surfactant concentration, concomitant with surfactant micellization. However, there may be a universal concentration of heat transfer enhancement not associated with micellization across a wide range of nonionic, anionic, and cationic surfactants. We hypothesize that this universal concentration is dictated by a balance of the advection of surfactants in bulk solution and the departure of surfactants adsorbed to bubble interfaces. The results of this work could ultimately pave the way towards simpler and more economical solutions to improve two-phase heat transfer processes.