(679d) The Influence of Surfactants in Contraction Dynamics of Liquid Sheets

In various applications such as atomization and polymer processing, liquid sheets (films with two free surfaces) are extruded from nozzles or dies into air. These sheets typically have nearly rectangular cross-sections but terminate with rounded ends that contract or retract towards each other due to surface tension forces. Liquid sheets ejected from agricultural spray nozzles but also in many other applications often contain surfactants, either intentionally or as contaminants, at the air-liquid interface. Previous research has demonstrated that surfactants can significantly alter the dynamics of planar films and filaments, either by influencing their breakup dynamics or by preventing end pinching (Wee et al., Phys. Rev. Fluids, 2022; Kamat et al., JFM, 2020). In this talk, we will report the results of a study investigating the effect of surfactants on the contraction dynamics of liquid sheets and provide a much needed but heretofore lacking extension of previous works of many others on systems with clean interfaces (e.g., Notz and Basaran, JFM, 2004; Savva and Bush, JFM, 2009).