Calorimetric determination of fragility in glass forming liquids: T(f) vs. T(g-onset) methods

Eur Phys J E Soft Matter. 2014 Jun;37(6):7. doi: 10.1140/epje/i2014-14052-y. Epub 2014 Jun 26.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't