Oil droplet self-transportation on oleophobic surfaces.
Oil droplet self-transportation on oleophobic surfaces.
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DOI：
10.1126/sciadv.1600148
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发表时间：
2016-06
期刊：
影响因子：
13.6
通讯作者：
Jokinen V
中科院分区：
文献类型：
--
作者：
Li J;Qin QH;Shah A;Ras RH;Tian X;Jokinen V
设计了能够无动力自传输油滴的疏油表面。定向液体输送对于各种生物过程和技术应用非常重要。尽管通过不对称化学改性或几何图案的表面工程促进了有效的液体操纵并使得水滴能够在合成表面上自传输，但油滴的自传输由于其低表面张力而构成了重大挑战。我们报告了油滴在疏油表面上的自传输，该疏油表面具有径向底切条纹阵列的微纹理。更重要的是，我们观察到油在不同样品表面上的三种运动模式，即向内运输、钉扎和向外扩散，这可以通过结构参数（包括条纹交叉角和宽度）进行切换。伴随的理论模型提供了对结构-液滴运动关系的深入机械理解。最后，我们揭示了如何优化纹理参数以最大化油滴自传输能力，并演示液体的自发液滴运动，表面张力低至 22.4 mN/m。这里介绍的表面为各种分析和流体设备中的无动力液体运输和油污染自去除应用开辟了新途径。
Oleophobic surfaces capable of power-free self-transportation of oil droplets are designed. Directional liquid transportation is important for a variety of biological processes and technical applications. Although surface engineering through asymmetric chemical modification or geometrical patterning facilitates effective liquid manipulation and enables water droplet self-transportation on synthetic surfaces, self-transportation of oil droplets poses a major challenge because of their low surface tension. We report oil droplet self-transportation on oleophobic surfaces that are microtextured with radial arrays of undercut stripes. More significantly, we observe three modes of oil motion on various sample surfaces, namely, inward transportation, pinned, and outward spreading, which can be switched by the structure parameters, including stripe intersection angle and width. Accompanying theoretical modeling provides an in-depth mechanistic understanding of the structure–droplet motion relationship. Finally, we reveal how to optimize the texture parameters to maximize oil droplet self-transportation capability and demonstrate spontaneous droplet movement for liquids down to a surface tension of 22.4 mN/m. The surfaces presented here open up new avenues for power-free liquid transportation and oil contamination self-removal applications in various analytical and fluidic devices.