论文标题
在表面纳米核成核的Hele-shaw细胞普遍性中溶剂交换
Solvent Exchange in a Hele-Shaw Cell Universality of Surface Nanodroplet Nucleation
论文作者
论文摘要
溶剂交换（也称为溶剂转移或OUZO效应）是一种通常用于大量纳米级液滴的自下而上的过程。在此过程中，某些油的良好溶剂被较差的溶剂所取代，从而导致油纳米核成核和随后的生长。在这里，我们在疏水底物上执行此过程，以便在Zhang等人的工作之后，将无柄液滴液滴进行。 [Zhang，X。; lu，Z。; Tan，H。; Bao，L。；嘿。;太阳，c。 Lohse，D。Proc。纳特。学院。科学。美国2015，122，9253-9257]。与该论文中所做的事情相反，我们选择了一个非常控制的Hele-shaw几何形状，具有可忽略的引力效应，将较差的溶剂注入Hele-Shaw细胞中心，并将出现的纳米单向表征为径向距离和流速的函数。我们发现，每个面积的平均液滴体积<vol> _area很大程度上取决于局部peclet编号PE，并遵循通用缩放定律<vol> _area〜pe^（3/4）。此外，无论流速和径向距离如何，液滴体积的概率分布函数也很大程度上取决于局部PE，从而为Zhang等人的工作中开发的溶剂交换过程的理论模型提供了强有力的支持。
Solvent exchange (also called solvent shifting or Ouzo effect) is a generally used bottom-up process to mass-produce nanoscale droplets. In this process, a good solvent for some oil is displaced by a poor one, leading to oil nanodroplet nucleation and subsequent growth. Here we perform this process on a hydrophobic substrate so that sessile droplets so-called surface nanodroplets-develop, following the work of Zhang et al. [Zhang, X.; Lu, Z.; Tan, H.; Bao, L.; He, Y.; Sun, C.; Lohse, D. Proc. Natl. Acad. Sci. U.S.A. 2015, 122, 9253-9257]. In contrast to what was done in that paper, we chose a very well-controlled Hele-Shaw geometry with negligible gravitational effects, injecting the poor solvent in the center of the Hele-Shaw cell, and characterize the emerging nanodroplets as a function of radial distance and flow rates. We find that the mean droplet volume per area <Vol>_area strongly depends on the local Peclet number Pe and follows a universal scaling law <Vol>_area~Pe^(3/4). Moreover, the probability distribution function of the droplet volume strongly depends on the local Pe as well, regardless of the flow rates and radial distance, giving strong support to the theoretical model of the solvent exchange process developed in Zhang et al.'s work.
