Hallavant Kylian, Mejres Marouane, Schawe Jürgen E K, Esposito Antonella, Saiter-Fourcin Allisson
Univ Rouen Normandie, INSA Rouen Normandie, CNRS, Groupe de Physique des Matériaux UMR 6634, F-76000 Rouen, France.
Mettler-Toledo GmbH, Analytical, 8606 Nänikon, Switzerland.
J Phys Chem Lett. 2024 Apr 25;15(16):4508-4514. doi: 10.1021/acs.jpclett.4c00632. Epub 2024 Apr 18.
The kinetics of the glass transition and the characteristic size of the fluctuating spatio-temporal domains in supercooled glass-forming liquids, i.e., the Cooperatively Rearranging Regions (CRR), were measured upon cooling over a broad range of cooling rates using Differential Scanning Calorimetry (DSC) and chip-based Fast Scanning Calorimetry (FSC). The investigations were conducted on a selection of fragile glass formers (fragility indices between 80 and 140), with a large variance in the atomic or molecular structure but comparable thermal glass transition temperatures , with the aim of evaluating the influence of chemical composition and structure on the CRR size and the associated temperature fluctuation. The selected materials are two polymers (poly(vinyl acetate) (PVAc), poly(lactic acid) (PLA)) as well as the simplest chalcogenide glass-former (selenium). It turned out that the CRR size plotted against the reduced temperature / follows the same trend, irrespective of the considered glass-former.
