Thermal and Mass Diffusion in a Semidilute Good Solvent-Polymer Solution
Thermal and Mass Diffusion in a Semidilute Good Solvent-Polymer Solution
复制标题
半稀良溶剂-聚合物溶液中的热扩散和质量扩散
DOI：
10.1063/1.479498
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发表时间：
1999
影响因子：
4.4
通讯作者：
J. Douglas
中科院分区：
文献类型：
--
作者：
K. J. Zhang;M. Briggs;R. Gammon;J. Sengers;J. Douglas
本文用光束偏转法测定了聚苯乙烯在甲苯中的Soret系数ST和集体（质量）扩散系数Dc。我们的测量结果表明，ST规模与聚合物的平移扩散系数在稀溶液中，呈现幂律缩放与聚合物浓度，和聚合物分子量在半稀释溶液中的独立。这些发现是一致的，与已知的缩放1/Dc在稀和半稀聚合物溶液中，相对不敏感的热扩散系数Dth的聚苯乙烯在甲苯中的聚合物浓度，和关系ST=Dth/Dc从不可逆热力学。我们能够代表我们的ST和直流数据的理论动机减少浓度的主曲线，但浓度-分子质量标度变量被发现是不同的每个传输属性，结果与理论相反…
The Soret coefficient ST and collective (mass) diffusion coefficient Dc of polystyrene dissolved in the good-solvent toluene has been measured over a range of concentrations and molecular masses with an optical beam-deflection method. Our measurements indicate that ST scales inversely with the polymer translational diffusion coefficient in dilute solutions, exhibits a power-law scaling with polymer concentration, and an independence of polymer molecular mass in semidilute solutions. These findings are consistent with the known scaling of 1/Dc in dilute and semidilute polymer solutions, the relative insensitivity of the thermal-diffusion coefficient Dth of polystyrene in toluene to polymer concentration, and the relation ST=Dth/Dc from irreversible thermodynamics. We are able to represent our ST and Dc data by theoretically motivated reduced-concentration master curves, but the concentration-molecular mass scaling variables are found to be different for each transport property, a result contrary to theoret...