Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, Alberta T2N 1N, Canada.
Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA.
Phys Rev Lett. 2023 Jan 20;130(3):034001. doi: 10.1103/PhysRevLett.130.034001.
The presence of submicrometer structures at liquid-fluid interfaces modifies the properties of many science and technological systems by lowering the interfacial tension, creating tangential Marangoni stresses, and/or inducing surface viscoelasticity. Here we experimentally study the break-up of a liquid filament of a silica nanoparticle dispersion in a background oil phase that contains surfactant assemblies. Although self-similar power-law pinch-off is well documented for threads of Newtonian fluids, we report that when a viscoelastic layer is formed in situ at the interface, the pinch-off dynamics follows an exponential decay. Recently, such exponential neck thinning was found theoretically when surface viscous effects were taken into account. We introduce a simple approach to calculate the effective relaxation time of viscoelastic interfaces and estimate the thickness of the interfacial layer and the viscoelastic properties of liquid-fluid interfaces, where the direct measurement of interfacial rheology is not possible.
在液体-流体界面存在亚微米结构会通过降低界面张力、产生切向马兰戈尼应力和/或诱导表面粘弹性来改变许多科学和技术系统的性质。在这里，我们通过实验研究了含有表面活性剂组装体的背景油相中二氧化硅纳米颗粒分散体的液体细丝的断裂。尽管牛顿流体的相似幂律扭结已得到很好的记录，但我们报告说，当界面上原位形成粘弹性层时，扭结动力学遵循指数衰减。最近，当考虑表面粘性效应时，理论上发现了这种指数颈缩。我们引入了一种简单的方法来计算粘弹性界面的有效弛豫时间，并估计界面层的厚度和液体-流体界面的粘弹性性质，在这种情况下，无法直接测量界面流变学。
