Nonuniversal nature of dynamic critical anomaly in polymer solutions.
Nonuniversal nature of dynamic critical anomaly in polymer solutions.
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聚合物溶液中动态临界异常的非普遍性质。
DOI：
10.1103/physreve.65.021802
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
N. Takubo
中科院分区：
文献类型：
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作者：
Hajime Tanaka;Y. Nakanishi;N. Takubo
研究了理想聚合物溶液的临界粘度异常，重点关注其对聚合物分子量 M(w) 的依赖性。根据聚合物溶液应与经典流体属于同一动态通用类别的传统理解，粘度的临界指数y(c)应为通用常数（约0.04）。与此相反，我们发现 y(c) 随着 M(w) 的增加而显着减少。这种不寻常的行为可以通过临界浓度波动与聚合物溶液固有的附加慢粘弹性模式的动态耦合来解释。我们的动态光散射测量支持了这一观点。
Critical anomaly of viscosity has been studied for ideal polymer solutions, focusing on its dependence on the molecular weight of polymer M(w). According to the conventional understanding that polymer solutions should belong to the same dynamic universal class as classical fluids, the critical exponent of viscosity y(c) should be a universal constant (approximately 0.04). Contrary to this, we find that y(c) significantly decreases with increasing M(w). This unusual behavior can be explained by the dynamic coupling of critical concentration fluctuations with an additional slow viscoelastic mode intrinsic to polymer solutions. Our dynamic light scattering measurements support this picture.