Jedrzejowska A, Matussek M, Ngai K L, Grzybowska K, Jurkiewicz K, Paluch M
Institute of Physics, University of Silesia, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland.
Silesian Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1, 41-500 Chorzow, Poland.
Phys Rev E. 2020 Jan;101(1-1):010603. doi: 10.1103/PhysRevE.101.010603.
In this Rapid Communication we report the unusual dynamics of planar, rigid, and anisotropy glass-forming molecules of unusually large size by dielectric spectroscopy by using two examples. The size of the molecules is much larger than the dipolar moiety located at the end of the longer axis of each molecule. The observed dynamics deviates strongly from the anticorrelation between β_{KWW} (fractional exponent of the Kohlrausch-Williams-Watts function) and dielectric strength, Δɛ(T_{g}), established generally for small van der Waals molecular glass formers. Moreover, the dynamics of the two large molecules differ greatly, albeit the difference is the dipole moment being orthogonal or parallel to the longer axis of the molecules. The drastic variation in dielectric response of the two materials coming from different portions of the structural α-relaxation spectrum is probed by the dipole. Thus, the new behavior opens up a new research area of the dynamics and thermodynamics of nonpolymeric sizable molecules, the dielectric response of which can be varied by the design of the dipole moiety.
在本快报中，我们通过介电谱法，利用两个实例报告了尺寸异常大的平面、刚性且各向异性玻璃形成分子的异常动力学。分子尺寸远大于位于每个分子较长轴末端的偶极部分。观察到的动力学与通常为小范德华分子玻璃形成体所确立的βKWW（科尔劳施－威廉姆斯－瓦特函数的分数指数）和介电强度Δɛ(Tg)之间的反相关性有很大偏差。此外，尽管两种大分子的偶极矩与分子较长轴正交或平行，但它们的动力学差异很大。偶极探测了来自结构α弛豫谱不同部分的两种材料介电响应的剧烈变化。因此，这种新行为开辟了一个关于非聚合性较大分子动力学和热力学的新研究领域，其介电响应可通过偶极部分的设计来改变。
