Fast differential scanning calorimetry: new solutions in data treatment and applications to molecular glass-formers

Abstract

Fast scanning calorimetry is an experimental technique very appreciated for its capability of suppressing reorganization processes, thanks to its wide interval of scanning rates, several orders higher than that of conventional calorimeters; nevertheless, drawbacks still exist. In this paper we propose a novel way to estimate the dynamical thermal lag by using the temperatures of maximum slope of the heat flow through the glass transition when we are not in the optimal conditions to apply the existing methods based on a reference material added on both cells of the chip or on the fictive temperature. Moreover, a novel interpretation of the heat flow losses due to the sample depending on the scanning rate sign is provided, in order to rescale the measured specific heat capacity to that from conventional calorimetry. Finally, the use of the glass to liquid transition measured on heating is shown as a new manner to reveal static thermal gradients.