Theory of Liquid—Liquid Interface of Polymer Systems
Theory of Liquid—Liquid Interface of Polymer Systems
复制标题
聚合物体系液-液界面理论
DOI：
10.1295/polymj.8.96
复制
发表时间：
1976
期刊：
影响因子：
2.8
通讯作者：
T. Nose
中科院分区：
文献类型：
--
作者：
T. Nose
本文在Cahn和Hilliard理论的基础上，考虑到界面处聚合物线团尺寸的变化，提出了一个计算分层聚合物混合物和聚合物溶液的界面张力和界面厚度的理论。（1）在临界温度T_c附近，在相同链长m的聚合物混合物（对称体系）中，界面张力σ随m的1/2次方增大，而在聚合物溶液中，σ随m的-1/4次方减小。另一方面，Tc附近的界面厚度随着m的增加而增加，与未扰动的链尺寸成比例，即，在对称聚合物体系中为m1/2，在聚合物溶液中为1/4次方。(2)在高分子体系中，从扩散界面到尖锐界面的一级转变被预测。由Tc降低的转变温度随m的增大而增大。在低温下的界面的厚度并不很大程度上取决于m，并且是段长度的数量级。
A theory for the interfacial tension and interface thickness of demixed polymer mixtures and polymer solutions is presented on the basis of the theory of Cahn and Hilliard, taking into account the change in the dimension of polymer coil at the interface. The following results are obtained from the theory: (1) Near critical temperature Tc in a polymer mixture with the same chain length m (a symmetrical system), interfaical tension σ increases with m in the 1/2 power of m, whereas in a polymer solution, σ decreases with m in the—1/4 power, compared at the same reduced temperature T/Tc. On the other hand, the thickness of the interface near Tc increases with increasing m, proportional to the unperturbed chain dimension, i.e., to m1/2, in a symmetrical polymer system, and to the 1/4 power in a polymer solution. (2) In high polymer systems, a first order transition from a diffuse interface to a sharp interface is predicted. The transition temperature reduced by Tc increase with increasing m. The thickness of the interface at a low temperature does not greatly depend on m and is of the order of a segment length.