Spontaneous Particle Ordering, Sorting, and Assembly on Soap Films

作者：Yang Shi, Danning Wang, Yuqing Xiao, Ting Pan, Wenpeng Liu, Luke P. Lee, Hongbao Xin, Baojun Li · 发表于：Nano Letters · 年份：2024 · DOI：10.1021/acs.nanolett.4c01840 · 被引用次数：9 · 研究领域：Pickering emulsions and particle stabilization、Block Copolymer Self-Assembly、Surface Modification and Superhydrophobicity

Soap bubbles exhibit abundant fascinating phenomena throughout the entire life of evolution with different fundamental physics governing them. Nevertheless, the complicated dynamics of small objects in soap films are still unrevealed. Here, we report the first observation of spontaneous particle ordering in a complicated galaxy of soap films without any external energy. The balance of interfacial tension at two liquid-gas interfaces is theoretically predicted to govern belted wetted particles (BWPs) traveling along a specified path spontaneously. Such spontaneous particle path-finding is found to depend on the particle size and hydrophilic properties. Spontaneous particle sorting is directly realized via these discrete and distinctive paths for different particles. The deformation of the soap membrane facilitates 1D/2D particle organization along the path. This observation represents the discovery of a new spontaneous order phenomenon in soap film systems and provides a new energy-free approach for particle separation and soft colloidal crystal assembly.