Science and Technology Division, Corning Incorporated, Corning, NY 14831, USA.
Proc Natl Acad Sci U S A. 2009 Nov 24;106(47):19780-4. doi: 10.1073/pnas.0911705106. Epub 2009 Nov 10.
The low-temperature dynamics of ultraviscous liquids hold the key to understanding the nature of glass transition and relaxation phenomena, including the potential existence of an ideal thermodynamic glass transition. Unfortunately, existing viscosity models, such as the Vogel-Fulcher-Tammann (VFT) and Avramov-Milchev (AM) equations, exhibit systematic error when extrapolating to low temperatures. We present a model offering an improved description of the viscosity-temperature relationship for both inorganic and organic liquids using the same number of parameters as VFT and AM. The model has a clear physical foundation based on the temperature dependence of configurational entropy, and it offers an accurate prediction of low-temperature isokoms without any singularity at finite temperature. Our results cast doubt on the existence of a Kauzmann entropy catastrophe and associated ideal glass transition.
超粘性液体的低温动力学是理解玻璃化转变和弛豫现象本质的关键,包括理想热力学玻璃化转变的潜在存在。不幸的是,现有的粘度模型,如 Vogel-Fulcher-Tammann(VFT)和 Avramov-Milchev(AM)方程,在低温下进行外推时会出现系统误差。我们提出了一个模型,该模型使用与 VFT 和 AM 相同数量的参数,对无机和有机液体的粘度-温度关系进行了改进描述。该模型基于构象熵的温度依赖性,具有明确的物理基础,并且在有限温度下没有奇点,能够准确预测低温等熵线。我们的结果对 Kauzmann 熵灾变和相关理想玻璃化转变的存在提出了质疑。