二元非晶体系中α与β_(JG)弛豫在强度与时间上的耦合研究  

Studies of coupling between α and β_(JG) relaxations in relaxation time and strength in binary glass-forming mixtures

作　　者：王梦[1] 李向前[1] 陈泽明[1] 王利民[1] 

机构地区：[1]燕山大学亚稳材料制备技术与科学国家重点实验室,河北秦皇岛066004

出　　处：《燕山大学学报》2015年第3期206-212,共7页Journal of Yanshan University

基　　金：国家重点基础研究发展规划(973计划)资助项目(2015CB856805);国家自然科学基金资助项目(11474247);河北省自然科学基金资助项目(A2014203260);河北省教育厅百名优秀人才支持计划资助项目(BR2-227)

摘　　要：针对由刚性极性分子为溶质和弱极性分子为溶剂构成的二元混合物,通过介电损耗实验,探究不同摩尔比例下α和βJG弛豫在强度和时间上的定量关系。发现α和βJG弛豫强度比值Δεα/Δεβ和弛豫时间对数比logτα/logτβ随温度均表现为线性关系,但是前者斜率随组分改变明显,相比之下后者斜率近似相等。也发现具有正混合热的二元混合体系中βJG弛豫时间越长,弛豫强度越高,这不同于纯物质中的行为,从极性分子所占自由体积与极性分子的数目两个方面进行了分析。本研究加深了对βJG弛豫物理本质的进一步认识和理解,同时为有效预测βJG弛豫的弛豫时间提供了工具。Dielectric measurements of the binary molecular mixtures composed of a rigid and polar liquid as solute and a non-polar liquid as solvent are performed to explore the correlation of the relaxation time and the relaxation strength of the α and βJG relaxa- tions in different compositions.The ratio of the relaxation strength for the α and βJG relaxations （△ε/△εβ） is found to increase lin- early with temperature but the slopes differ notably among the mixtures.In contrast, where as the ratio of the logarithmic relaxation time for the two relaxations （logrJlogr~） also shows a linear relation to temperature, the slopes basically keep constant, enabling the effective prediction of theβJG relaxation time.Meanwhile, quite different behaviors are found for the relaxation strength and relax- ation time in binary glass forming mixtures when compared with the pure glass formers, and the contributions from the free volume and the number of polar molecules in mixtures are discussed.The results would help the further understanding of the physics of the βJG relaxation.

关 键 词：玻璃转变 α弛豫βJG 弛豫 

分 类 号：O469[理学—凝聚态物理]