Malinowski Robert, Volpe Giovanni, Parkin Ivan P, Volpe Giorgio
Department of Chemistry, University College London , 20 Gordon Street, London WC1H 0AJ, United Kingdom.
Department of Physics, University of Gothenburg , 41296 Gothenburg, Sweden.
J Phys Chem Lett. 2018 Feb 1;9(3):659-664. doi: 10.1021/acs.jpclett.7b02831. Epub 2018 Jan 24.
The deposition of particles on a surface by an evaporating sessile droplet is important for phenomena as diverse as printing, thin-film deposition, and self-assembly. The shape of the final deposit depends on the flows within the droplet during evaporation. These flows are typically determined at the onset of the process by the intrinsic physical, chemical, and geometrical properties of the droplet and its environment. Here, we demonstrate deterministic emergence and real-time control of Marangoni flows within the evaporating droplet by an external point source of vapor. By varying the source location, we can modulate these flows in space and time to pattern colloids on surfaces in a controllable manner.
通过蒸发的固着液滴使颗粒沉积在表面上，这对于诸如打印、薄膜沉积和自组装等各种现象而言都很重要。最终沉积物的形状取决于蒸发过程中液滴内部的流动。这些流动通常在过程开始时由液滴及其环境的固有物理、化学和几何特性决定。在此，我们展示了通过外部蒸汽点源在蒸发液滴内实现马兰戈尼流动的确定性出现和实时控制。通过改变源位置，我们可以在空间和时间上调节这些流动，从而以可控方式在表面上对胶体进行图案化处理。
