Surface roughness directed self-assembly of patchy particles into colloidal micelles
Surface roughness directed self-assembly of patchy particles into colloidal micelles
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DOI：
10.1073/pnas.1116820109
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发表时间：
2012-07-03
影响因子：
11.1
通讯作者：
Kegel, Willem K.
中科院分区：
文献类型：
--
作者：
Kraft, Daniela J.;Ni, Ran;Kegel, Willem K.
具有位点特异性定向相互作用的胶体粒子，即所谓的“斑块状粒子”，是具有合理设计性质的复杂结构的自底向上组装路线的有希望的候选者。在这里，我们提出了一个实验实现的补丁胶体粒子的基础上，材料独立的耗尽相互作用和表面粗糙度。粗糙的胶体弯曲，光滑的补丁被证明是唯一有吸引力的，由于其不同的重叠量。我们详细讨论的情况下，胶体与一个补丁，作为分子表面活性剂的模型，无论是相对于它们的几何形状和它们的相互作用。这些一片颗粒组装成类似于表面活性剂胶束的簇，其中胶体的光滑和有吸引力的侧面位于内部。我们称这些簇为“胶态胶束”。从一个均匀的状态开始的直接蒙特卡罗模拟产生的集群的大小分布，在实验中发现的很好的协议。与表面活性剂胶束的重要区别源于我们的模型系统的胶体性质，并通过模拟和理论上解决。我们的新的“补丁”模型系统开辟了自组装研究的可能性，有限大小的超结构，以及晶体与尚未访问的结构。
Colloidal particles with site-specific directional interactions, so called "patchy particles", are promising candidates for bottom-up assembly routes towards complex structures with rationally designed properties. Here we present an experimental realization of patchy colloidal particles based on material independent depletion interaction and surface roughness. Curved, smooth patches on rough colloids are shown to be exclusively attractive due to their different overlap volumes. We discuss in detail the case of colloids with one patch that serves as a model for molecular surfactants both with respect to their geometry and their interactions. These one-patch particles assemble into clusters that resemble surfactant micelles with the smooth and attractive sides of the colloids located at the interior. We term these clusters "colloidal micelles". Direct Monte Carlo simulations starting from a homogeneous state give rise to cluster size distributions that are in good agreement with those found in experiments. Important differences with surfactant micelles originate from the colloidal character of our model system and are investigated by simulations and addressed theoretically. Our new "patchy" model system opens up the possibility for self-assembly studies into finite-sized superstructures as well as crystals with as of yet inaccessible structures.