期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2019
卷号：116
期号：34
页码：16736-16741
DOI：10.1073/pnas.1904809116
出版社：The National Academy of Sciences of the United States of America
摘要：This paper presents physical-aging data for the silicone oil tetramethyl-tetraphenyl trisiloxane. The density and the high-frequency plateau shear modulus G ∞ were monitored following temperature jumps starting from fully equilibrated conditions. Both quantities exhibit a fast change immediately after a temperature jump. Adopting the material-time formalism of Narayanaswamy, we determine from the dielectric loss at 0.178 Hz the time evolution of the aging-rate activation energy. The relative magnitude of the fast change of the activation energy differs from that of the density, but is identical to that of G ∞ . In fact, the activation energy is proportional to G ∞ throughout the aging process, with minor deviations at the shortest times. This shows that for the silicone oil in question the dynamics are determined by G ∞ in—as well as out of—equilibrium.
关键词：physical aging ; TN formalism ; relaxation time activation energy
