Bregulla A P, Cichos F
Molecular Nanophotonics Group, Peter Debye Institute for Soft Matter Physics, Leipzig University, 04103 Leipzig, Germany.
J Chem Phys. 2019 Jul 28;151(4):044706. doi: 10.1063/1.5088131.
We measure the flow field around a pinned micrometer-sized self-thermophoretic Janus particle confined in a slit pore of different slit widths. The flow field is determined with the help of gold nanoparticles, which are thermophoretically inactive and thus do not respond to the generated temperature gradients directly. The flow fields are altered when the slit pore is narrowing and reveal clear features of thermo-osmotic flows generated by the temperature gradients along the confining glass cover slip surfaces. Based on these observations, we suggest that many observations of active and passive particle clustering around phoretic swimmers are influenced by such osmotic creep flows induced at the substrate boundary.
我们测量了一个固定在不同狭缝宽度的狭缝孔隙中的微米级自热泳贾纳斯粒子周围的流场。借助金纳米颗粒确定流场，金纳米颗粒是热泳惰性的，因此不会直接响应所产生的温度梯度。当狭缝孔隙变窄时，流场会发生变化，并揭示出沿限制玻璃盖玻片表面的温度梯度产生的热渗透流的清晰特征。基于这些观察结果，我们认为，在电泳泳动体周围主动和被动粒子聚集的许多观察结果都受到在基底边界处诱导的这种渗透蠕变流的影响。
