Structural relaxation dynamics in binary glass-forming molecular liquids with ideal and complex mixing behavior

Wang, LM; Tian, Y; Liu, R; Richert, R

HERO ID

1005768

Reference Type

Journal Article

Year

2010

Language

English

PMID

20178328

HERO ID 1005768
In Press No
Year 2010
Title Structural relaxation dynamics in binary glass-forming molecular liquids with ideal and complex mixing behavior
Authors Wang, LM; Tian, Y; Liu, R; Richert, R
Journal Journal of Physical Chemistry B
Volume 114
Issue 10
Page Numbers 3618-3622
Abstract The glass transition and structural relaxation dynamics of various binary glass-forming liquids are investigated with dielectric relaxation measurements across the entire composition range. Three categories of solutions with weak, intermediate, and strong mixing effects, namely methyl-m-toluate in methyl o-toluate, methyl m-toluate in di-n-butyl phthalate, and 1,2-propandiol in 2-hexylamine, are selected to address the mixing behaviors from near-ideal to nonideal cases. The glass transition temperatures, fragility indices, and stretching exponents of the solutions are determined and their composition dependence is the focus of this study. The experimental measurements show that mixing generally generates a negative deviation of fragility m relative to the composition average of the results of two neat components (ideal mixing law). This excess negative fragility proves to be a universal feature of binary systems, and the increase of the nonideal mixing degree results in a more pronounced negative deviation. In contrast, the composition dependence of the stretching exponents is more complex, and a transition from the negative to positive deviation is observed for substantial nonideal character. The study assists understanding the dynamics of multicomponent glass formers.
Doi 10.1021/jp912223j
Pmid 20178328
Wosid WOS:000275328400027
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Is Qa No