TY  - JOUR
AU  - de Gans, B.-J.
AU  - Wiegand, S.
AU  - Luettmer-Strathmann, J.
TI  - Unusual Thermal Diffusion in Polymer Solutions
JO  - Physical review letters
VL  - 91
SN  - 0031-9007
CY  - College Park, Md.
PB  - APS
M1  - PreJuSER-32997
SP  - 245501-4
PY  - 2003
N1  - Record converted from VDB: 12.11.2012
AB  - 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.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000187202000041
DO  - DOI:10.1103/PhysRevLett.91.245501
UR  - https://juser.fz-juelich.de/record/32997
ER  -