LATTICE MODEL OF MICROEMULSIONS
LATTICE MODEL OF MICROEMULSIONS
复制标题
DOI：
10.1103/physrevb.41.9148
复制
发表时间：
1990-05-01
影响因子：
3.7
通讯作者：
SCHICK, M
中科院分区：
文献类型：
--
作者：
GOMPPER, G;SCHICK, M
用平均场理论研究了一个简单的油、水和两亲性的模型，其中第三个模型的能量倾向于坐在另两个模型之间。存在富油、富水、无序流体和片层相。相图显示了在这类体系中常见的从两相到三相再到两相共存的过程。计算了表征无序流体的三个独立的结构函数，以确定它是否可以用微乳液来识别。结果表明，这种流体相存在的区域可以分为关联函数在远距离单调衰减的区域和关联函数非单调衰减的区域。我们将后者与微乳联系起来。这两个区域之间没有相变。在微乳液中，低波数下的水-水结构函数具有Teubner和Strey提出的形式，其系数由我们确定。给出了结构函数沿不同热力学路径的行为，以及对于平衡和非平衡系统的行为。与实验的一致性在质量上是好的。
A simple model of oil, water, and amphiphile, in which the third is favored energetically to sit between the other two, is studied in three dimensions via mean-field theory. Oil-rich, water-rich, disordered fluid, and lamellar phases exist. Phase diagrams show the progression from two-phase to three-phase to two-phase coexistence commonly observed in such systems. Three independent structure functions characterizing the disordered fluid are calculated to determine whether it can be identified with a microemulsion. It is found that the region in which this fluid phase exists can be divided into a part in which correlation functions decay monotonically at large distances, and another in which their decay is nonmonotonic. We identify the latter with the microemulsion. There is no phase transition between the two regions. In the microemulsion, the water-water structure function at low wave number has the form proposed by Teubner and Strey, with coefficients that we determine. The behavior of the structure functions along different thermodynamic paths, and for systems both balanced and not, is presented. Agreement with experiment is qualitatively good.