Department of Physics, University of Massachusetts, Amherst, MA 01003, USA.
Polymer Science and Engineering Department, University of Massachusetts, Amherst, MA 01003, USA.
Science. 2018 Feb 16;359(6377):775-778. doi: 10.1126/science.aao1290.
Many complex fluids rely on surfactants to contain, protect, or isolate liquid drops in an immiscible continuous phase. Thin elastic sheets can wrap liquid drops in a spontaneous process driven by capillary forces. For encapsulation by sheets to be practically viable, a rapid, continuous, and scalable process is essential. We exploit the fast dynamics of droplet impact to achieve wrapping of oil droplets by ultrathin polymer films in a water phase. Despite the violence of splashing events, the process robustly yields wrappings that are optimally shaped to maximize the enclosed fluid volume and have near-perfect seams. We achieve wrappings of targeted three-dimensional (3D) shapes by tailoring the 2D boundary of the films and show the generality of the technique by producing both oil-in-water and water-in-oil wrappings.
许多复杂流体依赖于表面活性剂来容纳、保护或隔离不混溶连续相中的液滴。薄弹性片可以在由毛细力驱动的自发过程中包裹液滴。为了使片材的封装具有实际可行性，快速、连续和可扩展的工艺是必不可少的。我们利用液滴冲击的快速动力学在水相中实现了超薄聚合物薄膜对油滴的包裹。尽管飞溅事件很剧烈，但该过程仍然能够产生形状最佳的包裹物，以最大化封闭的流体体积，并具有近乎完美的接缝。我们通过定制薄膜的 2D 边界来实现目标三维（3D）形状的包裹，并通过产生水包油和油包水的包裹来展示该技术的通用性。
