Probing Colloidal Assembly on Non-Axisymmetric Droplet Surfaces via Electrospray
Probing Colloidal Assembly on Non-Axisymmetric Droplet Surfaces via Electrospray
复制标题
通过电喷雾探测非轴对称液滴表面上的胶体组装
DOI：
10.1021/acs.langmuir.2c02729
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发表时间：
2023
期刊：
影响因子：
3.9
通讯作者：
Chiarot, Paul R.
中科院分区：
文献类型：
--
作者：
Prisaznuk, Joseph M.;Huang, Peter;Yong, Xin;Chiarot, Paul R.
滞留在固着液滴表面的微粒通过静电和毛细管力相互作用。流体-流体界面上胶体的组装受颗粒尺寸、表面化学和接触线粗糙度的控制。我们使用表面能图案创建非球形液滴，并通过电喷雾雾化将微粒传递到液-气界面。使用水滴作为目标，观察颗粒组装随时间的变化。我们发现下面的表面能模式显着影响胶体组装并驱使粒子流向液滴中心。颗粒排列成具有局部六边形排序的单个非密堆积簇，但在接触线附近留下了一个清晰的区域，其中颗粒很少。该耗尽区归因于用于创建表面能图案的光致抗蚀剂的长程静电排斥，该表面能图案保留了来自电喷雾的电荷。为了了解静电相互作用的影响，我们探索了具有不同介电特性的目标液滴。使用图案化基底和电喷雾进行粒子沉积，我们可以利用流体界面处的胶体组装来构建可重复的单层图案。
Microparticles trapped on the surface of a sessile droplet interact via electrostatic and capillary forces. The assembly of colloids at a fluid–fluid interface is governed by particle size, surface chemistry, and contact line roughness. We created nonspherical droplets using surface energy patterning and delivered microparticles to the liquid–air interface with electrospray atomization. Using a water droplet as the target, the particle assembly was observed over time. We found that the underlying surface energy pattern significantly influenced the colloidal assembly and drove particles toward the center of the droplet. The particles were arranged into a single, non-close-packed cluster with local hexagonal ordering but left a clear region with very few particles near the contact line. This depletion region is attributed to long-range electrostatic repulsion from the photoresist used to create the surface energy pattern, which retained electric charge from the electrospray. To understand the effect of electrostatic interactions, we explored target droplets with dissimilar dielectric properties. Using patterned substrates and electrospray for particle deposition, we can harness the assembly of colloids at a fluid interface to build repeatable monolayer patterns.