Zhu Yiwei, Bansal Artee, Xi Shun, Lu Jinxin, Chapman Walter G
Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA.
Rice University, Houston, TX, USA.
Soft Matter. 2020 Apr 15;16(15):3806-3820. doi: 10.1039/d0sm00248h.
Patchy colloids and associating fluids have attracted continued interest due to the interesting phase behavior and self-assembly in solution. The ability to fabricate patchy colloids with multiple attractive surface patches of different number, size, shape, and relative location makes patchy colloids a good candidate as building blocks to form complex advanced materials. However, a theory that clearly relates the self-assembled structures that form based on the anisotropic interactions has been missing. Although Wertheim's theory in the form of the SAFT model is widely used to predict self-assembly and phase behavior in solution, SAFT does not include multibody correlations necessary to model any shape of association site or sites that can form multiple bonds. We have recently developed a new theory for associating colloids that naturally incorporates multibody correlations based on a cluster distribution approach due to Bansal, Asthagiri, Marshall, and Chapman (BAMC). In this paper, we extended the cluster distribution theory to predict the thermodynamic properties and phase behavior of binary systems consisting of anisotropic particles with any geometry of bonding site. In particular, we consider self-assembly of Janus particles, Saturn particles, and ternary particles mixed with solvent colloids that have two directional patchy sites. Good agreement between theoretical predictions and molecular simulation is shown for self-assembly, thermodynamic properties in this system. Re-entrant phase behavior has been investigated and low density gels is predicted.
由于在溶液中有趣的相行为和自组装特性，补丁状胶体和缔合流体一直备受关注。能够制造出具有不同数量、大小、形状和相对位置的多个吸引性表面补丁的补丁状胶体，使得其成为构建复杂先进材料的理想候选构建单元。然而，一直缺少一个能清晰关联基于各向异性相互作用形成的自组装结构的理论。尽管以SAFT模型形式存在的韦特海姆理论被广泛用于预测溶液中的自组装和相行为，但SAFT并不包括对任何形状的缔合位点或能形成多个键的位点进行建模所需的多体相关性。我们最近基于班萨尔、阿斯塔吉里、马歇尔和查普曼（BAMC）提出的簇分布方法，开发了一种用于缔合胶体的新理论，该理论自然地纳入了多体相关性。在本文中，我们扩展了簇分布理论，以预测由具有任意键合位点几何形状的各向异性颗粒组成的二元体系的热力学性质和相行为。特别地，我们考虑了与具有两个定向补丁位点的溶剂胶体混合的双面神颗粒、土星颗粒和三元颗粒的自组装。对于该体系中的自组装和热力学性质，理论预测与分子模拟结果显示出良好的一致性。我们还研究了再入相行为并预测了低密度凝胶的存在。
