School of Mathematics, Statistics and Mechanics, Beijing University of Technology, Beijing 100124, China.
College of Mechanical and Energy Engineering, Beijing University of Technology, Beijing 100124, China.
Colloids Surf B Biointerfaces. 2024 Dec;244:114178. doi: 10.1016/j.colsurfb.2024.114178. Epub 2024 Aug 28.
This article investigates the equilibrium arrangement, self-assembly process, and subsequent curing of amphiphilic snowman-shaped Janus particles at the oil-water interface. The independent Janus particles are in vertical equilibrium state and the contact position of the oil-water interface is at the largest cross section of the particle's hydrophobic phase. Under the effect of the surface tension and the adsorption of materials, Janus particles may form particle combinations including the particle pairs and the particle triangle, whose inner and outer sides have the liquid surface exhibiting completely opposite contact angles. Particle combinations form stable parallel double-chain structures with diverse shapes after the self-assembly process. However, the single Janus particles attain a state of mechanical equilibrium under the influence of surrounding particles, enabling them to assemble into regular array structures. The relationship of interfacial tension coefficient between phases can be changed by adjusting the oil-water system, which leads to variations in the self-assembly speed and the final arrangement results. The thin-film with uniformly distributed vertical particles is achieved by replacing the underlying deionized water with a curing agent. Based on the understanding of the interactions between irregularly shaped Janus particles at the oil-water interface, it will be convenient to achieve the controllable self-assembly and widely applications of these particles.
本文研究了两亲性雪人型 Janus 粒子在油水界面处的平衡排列、自组装过程和随后的固化。独立的 Janus 粒子处于垂直平衡状态，油水界面的接触位置位于粒子疏水区的最大横截面上。在表面张力和材料吸附的作用下，Janus 粒子可能形成包括粒子对和粒子三角形在内的粒子组合，其内外两侧的液体表面具有完全相反的接触角。自组装过程后，粒子组合形成具有多种形状的稳定平行双链结构。然而，在周围粒子的影响下，单个 Janus 粒子达到机械平衡状态，从而能够组装成规则的阵列结构。通过调整油水体系，可以改变相间界面张力系数，从而改变自组装速度和最终排列结果。通过用固化剂替代底层去离子水，可以得到垂直分布的均匀粒子的薄膜。基于对油水界面处不规则形状 Janus 粒子相互作用的理解，将有助于实现这些粒子的可控自组装和广泛应用。
