物理化学学报 >> 2012, Vol. 28 >> Issue (09): 2023-2028.doi: 10.3866/PKU.WHXB201206061

热力学,动力学和结构化学 上一篇    下一篇

三乙酸甘油酯玻璃化转变的焓弛豫与介电弛豫研究

陈泽明, 毕东阳, 王利民   

  1. 燕山大学材料科学与工程学院, 亚稳材料制备技术与科学国家重点实验室, 河北秦皇岛 066004
  • 收稿日期:2012-04-17 修回日期:2012-06-06 发布日期:2012-08-02
  • 通讯作者: 王利民 E-mail:limin_wang@ysu.edu.cn
  • 基金资助:

    国家自然科学基金(51071138), 河北省自然科学基金(A2010002048)和燕山大学优秀博士生科学基金(YSUSF201102)资助项目

Enthalpy and Dielectric Relaxations of Triacetin in the Vicinity of Glass Transition

CHEN Ze-Ming, BI Dong-Yang, WANG Li-Min   

  1. State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004, Hebei Province, P. R. China
  • Received:2012-04-17 Revised:2012-06-06 Published:2012-08-02
  • Contact: WANG Li-Min E-mail:limin_wang@ysu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51071138), Natural Science Foundation of Hebei Province, China (A2010002048), and Science Foundation of Yanshan University for the Excellent Ph. D. Students, China (YSUSF201102).

摘要:

脆性较高的玻璃形成分子液体通常在焓弛豫和介电弛豫动力学上表现出明显的差异性, 为了深入理解这一问题, 本文针对具有较高液体脆性的三乙酸甘油酯对比研究了焓弛豫与介电弛豫行为. 利用这两个技术分别研究了结构弛豫动力学过程的非Arrhenius 与非指数特征, 液体脆性因子与非指数性因子的对比显示很好的一致性. 分析表明分子的柔性有可能对这两种弛豫过程中分子运动的相关性产生明显的影响. 讨论了玻璃形成液体的分子结构与动力学参数之间的关联.

关键词: 玻璃转变, 过冷液体, 结构弛豫, 焓弛豫, 介电弛豫

Abstract:

To understand the experimental observation that the dynamic parameters determined for enthalpy and dielectric relaxation might differ in fragile glass-forming molecular liquids, a fragile molecular liquid, triacetin, was chosen for the study of the two relaxation dynamics. The non-Arrhenius and nonexponential characters were focused, and the kinetic fragility and non-exponential parameter determined from the two relaxation measurements were found to be remarkably similar. Experimental results indicate that the degree of correlation in the molecular motions involved in the two relaxations depends on molecular flexibility. The dependence of the dynamic parameters on molecular structures in the glass forming liquids is discussed.

Key words: Glass Transition, Supercooled Liquid, Structural Relaxation, Enthalpy Relaxation, Dielectric Relaxation

MSC2000: 

  • O649