The Excess Heat Capacity in Glass-forming Liquid Systems Containing Molecules
Abstract
The excess heat capacity at glass transition temperature in two types of glass-forming systems of [xNaNO3·(1-x)KNO3]60[Ca(NO3)2]40 (0 ≤ x ≤ 1) and Ca(NO3)2·yH2O (4 ≤ y ≤ 13) is studied. In the former system, with the replacement of K+ cation with Na+ cation, the excess heat capacity is almost invariable around 65.1 J·mol-1·K-1, while the excess increases by 38.9 J·mol-1·K-1 with the increasing per molar H2O content in latter system. A quantitative description of the excess heat capacity is built up with the consideration of atomic and molecular translational motion in the glass-forming systems. This finding might offer further understanding to the glass transition.
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