Temperature and pressure dependence of the order parameter fluctuations, conformational compressibility, and the phase diagram of the PEP-PDMS diblock copolymer

被引：68

作者：

Schwahn, D ^{[1
]}

Frielinghaus, H ^{[1
]}

Mortensen, K ^{[1
]}

Almdal, K ^{[1
]}

机构：

[1] RISO NATL LAB, DEPT SOLID STATE PHYS, DK-4000 ROSKILDE, DENMARK

来源：

PHYSICAL REVIEW LETTERS | 1996年 / 77卷 / 15期

关键词：

D O I：

10.1103/PhysRevLett.77.3153

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The structure factor of a poly(ethylene-propylene)-poly(dimethylsiloxane) diblock copolymer has been measured by small-angle neutron scattering as a function of temperature and pressure. The conformational compressibility exhibits a pronounced maximum at the order-disorder phase transition. The phase boundary shows an unusual shape. With increasing pressure it first decreases and then increases. Its origin is an increase, respectively, of the entropic and of the enthalpic part of the Flory-Huggins interaction parameter. The Ginzburg parameter describing the limit of the mean-field approximation is not influenced by pressure.

引用

页码：3153 / 3156

页数：4