Does the entropy and volume dependence of the structural α-relaxation originate from the Johari–Goldstein β-relaxation?

Why is the change of the Johari–Goldstein β-relaxation time by densification in ultrastable glass minor?

“…As mentioned in the Introduction, to explain the properties of the JG b-relaxation in USG compared with the OG we shall apply two general dynamic and thermodynamic properties of the a-relaxation and JG b-relaxation established before from studies at elevated pressures in molecular glass-formers. [20][21][22][23][24][25][26][27] The application is justified by the fact that density is increased at elevated pressure, and the increase can be comparable to or even larger than that in USG. Through the application, we are able to explain why the Johari-Goldstein (JG) b-relaxation time, t b , in USG of toluene, 13 etoricoxib 14 and telmisartan 15 is about an order of magnitude longer than that in OG, and has nearly the same activation energy E b .…”

“…Notwithstanding, the much smaller changes of t b and E b by densification in USG are in stark contrast to the behavior of the a-relaxation time t a , and this remarkable experimental observation deserves an explanation. In this paper, we provide an explanation based on two general properties established from the studies of glasses and liquids at elevated pressures [20][21][22][23][24][25][26][27] and applied it to USG. The increase in density of the glasses formed under high pressure can be even larger than that in USG, and hence the general properties should apply.…”

Why is surface diffusion the same in ultrastable, ordinary, aged, and ultrathin molecular glasses?

“…34 On the other hand, a small increase of peak frequency was found on aging of dipropyleneglycol dibenzoate. 35 In all cases, including others not mentioned, there is either no change or a small change of t b by physical aging. From this general aging property of t b (T), it follows from eqn (6) and (7) that t S (T) and D S (T) of the aged TPD glass are nearly the same as that of OG, as found by Fakhraai and coworkers.…”

“…35 In Fig. S2-S4 (ESI †) are the data of t b and t a of the three glass-formers shown at a fixed temperature as a function of pressure, and at a fixed pressure as a function of temperature.…”

Temperature and pressure dependence of secondary process in an epoxy system

“…[4][5][6][7][8][9][10][11] The latter have been shown to be (in some cases) related to the structural process, and to be involved in the vitrification process. 1-3 In recent years the attention was focused not only on the structural process, traditionally related to the glass transition, but also on the secondary processes.…”