Entropy-Enthalpy compensation effects in dielectric relaxation processes have been observed in a wide array of glass forming liquids [1]. These effects have been demonstrated in both the structural relaxation process, as well as the secondary Johari-Goldstein (J-G) beta process. Furthermore these effects hold for a variety of methods of changing the energy landscape [2]. These include: chain length variation, simulation of randomly pinned particles, as well as both simulation and experimental results in thin films.

We demonstrate that this type of behavior can be accounted for using a Space-Time percolation model applied in relation with the cooperative rearranging regions. This provides the first step towards a more comprehensive model capable of providing physical meaning for some of the compensation parameters. Based on these parameters and on the proposed model we further present a new connection linking the structural relaxation with the secondary J-G relaxation process.

The proposed link between the compensation effects in these two distinct types of processes, also provides a new way of characterizing some of these materials. Based on findings in biological tissues in which the appearance of glassy dynamics was recent noted [3], we suggest applying these results there as well, in order to provide further insight into the microscopic origins of this behavior.

[1] S. E. Lerner, P. Ben Ishai, and Y. Feldman, “Entropy-Enthalpy Compensation in Glass Formers,” Paper presented at the 9th International Conference on Broadband Dielectric Spectroscopy and its Applications, September 11-16, 2016; Pisa , Italy 

[2]  S. E. Lerner, P. Ben Ishai, and Y. Feldman, “New Link between Structural and Johari-Goldstein Relaxation Parameters in Glass Formers,” Paper presented at the 10th International Conference on Broadband Dielectric Spectroscopy and its Applications, August 26-31, 2018; Brussels , Belgium

[3]  D. M. Sussman, M. Paoluzzi, M. C. Marchetti, and M. L. Manning, “Anomalous glassy dynamics in simple models of dense biological tissue,” EPL, vol. 121, no. 3, p. 36001, 2018.