School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
Adv Colloid Interface Sci. 2023 Feb;312:102844. doi: 10.1016/j.cis.2023.102844. Epub 2023 Jan 18.
Surfactants are employed in microfluidic systems not just for drop stabilisation, but also to study local phenomena in industrial processes. On the scale of a single drop, these include foaming, emulsification and stability of foams and emulsions using statistically significant ensembles of bubbles or drops respectively. In addition, surfactants are often a part of a formulation in microfluidic drop reactors. In all these applications, surfactant dynamics play a crucial role and need to be accounted for. In this review, the effect of surfactant dynamics is considered on the level of standard microfluidic operations: drop formation, movement in channels and coalescence, but also on a more general level, considering the mechanisms controlling surfactant adsorption on time- and length-scales characteristic of microfluidics. Some examples of relevant calculations are provided. The advantages and challenges of the use of microfluidics to measure dynamic interfacial tension at short time-scales are discussed.
表面活性剂不仅用于微流控系统中的液滴稳定，也用于研究工业过程中的局部现象。在单个液滴的尺度上，这些现象包括使用统计学上显著的气泡或液滴集合体分别进行的泡沫、乳化以及泡沫和乳液的稳定性。此外，表面活性剂通常是微流控液滴反应器配方的一部分。在所有这些应用中，表面活性剂动力学都起着至关重要的作用，需要加以考虑。在这篇综述中，考虑了表面活性剂动力学在标准微流控操作水平上的影响：液滴形成、在通道中的运动和聚结，但也在更一般的水平上，考虑了控制表面活性剂在微流控特有的时间和长度尺度上吸附的机制。提供了一些相关计算的例子。讨论了使用微流控技术在短时间尺度上测量动态界面张力的优点和挑战。
