Unusual thermal diffusion in polymer solutions

被引：76

作者：

de Gans, BJ

Kita, R

Wiegand, S

Luettmer-Strathmann, J

机构：

[1] Max Planck Inst Polymer Res, D-55128 Mainz, Germany

[2] Forschungszentrum Julich GmbH, IFF Weiche Mat, D-52428 Julich, Germany

[3] Univ Akron, Dept Phys, Akron, OH 44325 USA

来源：

PHYSICAL REVIEW LETTERS | 2003年 / 91卷 / 24期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1103/PhysRevLett.91.245501

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Thermal diffusion forced Rayleigh scattering results on thermal diffusion of poly(ethylene oxide) (PEO) in ethanol/water mixtures are presented. In water-rich solvent mixtures, PEO is found to migrate towards regions of lower temperature. This is typical for polymer solutions and corresponds to a positive Soret coefficient of PEO. In solvent mixtures with low water content, however, the polymer is found to migrate towards higher temperatures, corresponding to a negative Soret coefficient of PEO in ethanol-rich solutions. To our knowledge, this is the first observed sign change of the Soret coefficient of a polymer in solution. We also present a simple lattice model for the polymer solvent system and calculate Soret coefficients with statistical mechanics methods. The calculated values agree qualitatively with the experimental results.

引用

页码：1 / 245501

页数：4

共 18 条

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