https://doi.org/10.1140/epje/i2014-14052-y
Regular Article
Calorimetric determination of fragility in glass forming liquids: Tf vs. Tg-onset methods
State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, 066004, Hebei, China
* e-mail: Limin_Wang@ysu.edu.cn
Received:
24
January
2014
Revised:
29
May
2014
Accepted:
12
June
2014
Published online:
26
June
2014
The calorimetric determination of the fragility m-index is compared using the T f and T g-onset methods for typical metallic and molecular glass forming systems of Pd39Ni10Cu30P21, glycerol, triacetin and propylene carbonate. The results are evaluated by referring to the standard m-values determined from the kinetic measurements of the viscosity or structural relaxation time in the supercooled liquid regimes. The m-indexes derived from the T f method are found to generally agree well with the kinetic measurements for all the systems. However, a large deviation is shown between the m-indexes calculated with the T g-onset method and the kinetic results for the fragile liquids of triacetin and propylene carbonate, indicating the calorimetric determination of the fragility m-indexes in terms of the T f method produces less uncertainty.
Key words: Soft Matter: Colloids and Nanoparticles
© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg, 2014