Dipartimento di Fisica, Sapienza Università di Roma, Roma, Italy.
J Chem Phys. 2013 Apr 28;138(16):164505. doi: 10.1063/1.4801438.
We present a numerical study on the phase diagram for a simple model of Janus colloids, including ordered and disordered structures. Using a range of techniques, we generate a set of crystal structures and investigate their relative stability field in the pressure-temperature and temperature-density planes by means of free-energy calculations and thermodynamic integration schemes. We find that despite the Janus colloids' simple architecture, they form stable crystal structures with complicated bond-topologies on an underlying face-centered-cubic or hexagonal-close-packed lattice. In addition, we find a phase consisting of wrinkled bilayer sheets, competing with both the fluid and the crystal phases. We detect a metastable gas-liquid coexistence which displays a micellization-driven re-entrant behavior.
我们提出了一个简单的 Janus 胶体模型的相图的数值研究，包括有序和无序结构。使用一系列技术，我们生成了一组晶体结构，并通过自由能计算和热力学积分方案研究了它们在压力-温度和温度-密度平面上的相对稳定场。我们发现，尽管 Janus 胶体的结构简单，但它们在面心立方或六方密堆积晶格的基础上形成了具有复杂键拓扑结构的稳定晶体结构。此外，我们发现了一个由褶皱双层片组成的相，与流体相和晶体相竞争。我们检测到一个亚稳的气-液共存，表现出胶束化驱动的再进入行为。
