Abstract In the present study, the formation of surfactant-laden viscous drops in ambient air is experimentally investigated using a high-speed digital camera. The mixtures of 90%, 92.5%, and 95% glycerol by weight in water containing various concentrations of sodium dodecyl sulfate are chosen as the drop phase fluid. The focus of this work is to investigate the effects of concentration of surfactant dissolved in solutions with different viscosities, on physical and geometrical parameters related to drop formation process, such as the drop elongation, minimum neck thickness, formation time, and the drop volume. The formation of satellite drops and the influence of surfactant concentration on their size are also studied. The obtained results indicate that increasing the surfactant concentration and the viscosity of drop phase fluid, slows down the necking process and causes the drop detachment length to increase. The entire process of drop formation is divided into two stages, and it was found that adding surfactant to the solutions has inverse effects on the duration of these two stages. It was also shown that surfactant addition contributes to an increase in the size of the satellite drop due to generation of Marangoni stresses on the surface of the drop's neck.

中文翻译：

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表面活性剂对液滴形成过程动力学影响的实验研究

摘要 在本研究中，使用高速数码相机对环境空气中含有表面活性剂的粘性液滴的形成进行了实验研究。选择按重量计 90%、92.5% 和 95% 甘油在含有不同浓度十二烷基硫酸钠的水中的混合物作为滴相流体。这项工作的重点是研究溶解在不同粘度溶液中的表面活性剂浓度对与液滴形成过程相关的物理和几何参数的影响，如液滴伸长率、最小颈部厚度、形成时间和液滴体积。还研究了卫星液滴的形成和表面活性剂浓度对其尺寸的影响。所得结果表明，增加表面活性剂浓度和液滴相流体的粘度，减慢颈缩过程并导致液滴脱离长度增加。液滴形成的整个过程分为两个阶段，发现在溶液中加入表面活性剂对这两个阶段的持续时间有相反的影响。还表明，由于在液滴颈部表面产生 Marangoni 应力，表面活性剂的添加有助于卫星液滴尺寸的增加。