Spontaneous phase separation of ternary fluid mixtures.
Spontaneous phase separation of ternary fluid mixtures.
复制标题
三元流体混合物的自发相分离。
作者：
Shek ACM
本文用晶格玻尔兹曼方法计算研究了所有表面张力相等和表面张力不同时三元流体混合物的自发相分离。为了使可能的相分离机制的相图合理化，以前的理论工作通常依赖于分析由简单的线性稳定性分析得出的特征值的符号，但我们发现这并不能解释观察到的模拟结果。在这里，我们将可能的分离途径分为四种基本机制，并开发了一个现象学模型，该模型捕获了每种机制普遍存在的组成机制。我们进一步强调，三元相分离的主要机制涉及流体-流体界面处次要组分的富集和不稳定性，而在二元流体混合物中则不存在这种情况。
We computationally study the spontaneous phase separation of ternary fluid mixtures using the lattice Boltzmann method both when all the surface tensions are equal and when they have different values. To rationalise the phase diagram of possible phase separation mechanisms, previous theoretical works typically rely on analysing the sign of the eigenvalues resulting from a simple linear stability analysis, but we find this does not explain the observed simulation results. Here, we classify the possible separation pathways into four basic mechanisms, and develop a phenomenological model that captures the composition regimes where each mechanism is prevalent. We further highlight that the dominant mechanism in ternary phase separation involves enrichment and instability of the minor component at the fluid-fluid interface, which is absent in the case of binary fluid mixtures.