Bordi F, Cametti C, Paradossi G
Dipartimento di Medicina Interna, Università di Roma, Tor Vergata, Italy.
Biopolymers. 1996;40(5):485-94. doi: 10.1002/(SICI)1097-0282(1996)40:5%3C485::AID-BIP6%3E3.0.CO;2-S.
The dielectric properties of poly(alpha-glutamic acid) and poly(gamma-glutamic acid) aqueous solutions in the fully ionized state have been investigated in the frequency range from 1 MHz to 1 GHz by means of frequency-domain dielectric spectroscopy measurements. In this frequency range, micro-Brownian dynamics and internal motion of side-chain polar groups give rise to nonexponential relaxation processes resulting in an intermediate dielectric relaxation between that due to the counterion atmosphere polarization and that due to the orientational polarization of the water molecules. In this work, we study the influence of the polymer concentration in the dilute--semidilute regime on the dielectric parameters, i.e., the dielectric increment delta epsilon and the relaxation time tau, and discuss their relevance in the light of some scaling pictures recently proposed by Dobrynin, Colby, and Rubinstein to describe the unentangled regime of flexible polyelectrolyte solutions.
通过频域介电谱测量，研究了完全电离状态下聚（α - 谷氨酸）和聚（γ - 谷氨酸）水溶液在1 MHz至1 GHz频率范围内的介电性质。在该频率范围内，微布朗动力学和侧链极性基团的内部运动导致非指数弛豫过程，从而在由反离子气氛极化引起的弛豫和由水分子取向极化引起的弛豫之间产生中间介电弛豫。在这项工作中，我们研究了稀溶液 - 半稀溶液区域中聚合物浓度对介电参数的影响，即介电增量δε和弛豫时间τ，并根据Dobrynin、Colby和Rubinstein最近提出的一些标度图像讨论它们的相关性，这些图像用于描述柔性聚电解质溶液的非缠结状态。
