Surface tension (ST) relaxations are influential in industrial processes that are characterized by substantial surface deformations. Despite this, the dynamics of surfactant adsorption onto a dilating surface is still unclear. Recently, the ST relaxation of a non-ionic surfactant (TX-100) was reported (Lin et al. (2017) [17]), but little is known about the behavior of ionic surfactants. In this study, the relaxations of ST and surface dilational rates (λ) of ionic aerosol-OT (AOT) and sodium dodecyl sulfate (SDS) solutions were investigated by monitoring a continuously expanding bubble using a pendant bubble tensiometer. The data showed that during the rapid bubble expansion, ST of AOT solutions increased with time, while that of SDS changed negligibly. This implied that the mass transfer rate of AOT molecules from bulk to the bubble surface during expansion (at λ < 3 s⁻¹) is much slower than the depletion rate of AOT at the interface. Contrastingly, the mass transport of SDS molecules from bulk to the bubble surface is more rapid than the surfactant depletion rate at similar λ. A theoretical ST relaxation profile of an isolated bubble surface was also simulated, and it well described the experimental ST data of AOT solutions.

表面张力（ST）弛豫在以显着表面变形为特征的工业过程中具有影响力。尽管如此，仍然不清楚表面活性剂在膨胀表面上的吸附动力学。最近，有报道称非离子表面活性剂（TX-100）的ST弛豫（Lin等人（2017）[17]），但对离子表面活性剂的行为知之甚少。在这项研究中，通过使用悬垂式气泡张力计监测连续膨胀的气泡，研究了离子气溶胶-OT（AOT）和十二烷基硫酸钠（SDS）溶液的ST松弛和表面膨胀率（λ）。数据表明，在气泡快速膨胀期间，AOT解决方案的ST随时间增加，而SDS的ST的变化可忽略不计。^-1）比接口处AOT的耗尽速度慢得多。相反，在相似的λ下，SDS分子从本体到气泡表面的质量传输比表面活性剂的消耗速率更快。还模拟了孤立气泡表面的理论ST弛豫轮廓，并很好地描述了AOT溶液的实验ST数据。