Xu Yaxin, Jandhyala Prabhat, Takatori Sho C
Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, California 93117, USA.
J Chem Phys. 2024 Aug 14;161(6). doi: 10.1063/5.0220112.
Colloidal building blocks with re-configurable shapes and dynamic interactions can exhibit unusual self-assembly behaviors and pathways. In this work, we consider the phase behavior of colloids coated with surface-mobile polymer brushes that behave as "dynamic surfactants." Unlike traditional polymer-grafted colloids, we show that colloids coated with dynamic surfactants can acquire anisotropic macroscopic assemblies, even for spherical colloids with isotropic attractive interactions. We use Brownian Dynamics simulations and dynamic density functional theory to demonstrate that time-dependent reorganization of the dynamic surfactants leads to phase diagrams with anisotropic assemblies. We observed that the microscopic polymer distributions impose unique geometric constraints between colloids that control their packing into lamellar, string, and vesicle phases. Our work may help discover versatile building blocks and provide extensive design freedom for assembly out of thermodynamic equilibrium.
具有可重构形状和动态相互作用的胶体构建块可以展现出不同寻常的自组装行为和途径。在这项工作中，我们考虑了涂覆有作为“动态表面活性剂”的表面可移动聚合物刷的胶体的相行为。与传统的聚合物接枝胶体不同，我们表明涂覆有动态表面活性剂的胶体可以获得各向异性的宏观聚集体，即使对于具有各向同性吸引相互作用的球形胶体也是如此。我们使用布朗动力学模拟和动态密度泛函理论来证明动态表面活性剂的时间依赖性重组导致具有各向异性聚集体的相图。我们观察到微观聚合物分布在胶体之间施加了独特的几何约束，这些约束控制了它们堆积成层状、串状和囊泡相。我们的工作可能有助于发现通用的构建块，并为非平衡热力学组装提供广泛的设计自由度。
