Abstract

In this work, we report on a detailed study of the diffusional and vibrational dynamics of liquid ethylene glycol (EG: HO–CH2CH2–OH) in the bulk state and confined in a matrix of sol-gel porous glass with 26 Å interconnected cylindrical pores. The investigation is performed, by incoherent quasielastic and inelastic neutron scattering (IQENS and IINS), as a function of temperature. IQENS data have been definitively interpreted in terms of the α-relaxation dynamics predicted by mode coupling theory for supercooled liquids. We verified that a description by means of an Havriliak–Negami profile is consistent with the measured spectral line shape. Furthermore, IINS spectra show a clear different evolution versus T of the vibrational density of states, Z(ω), passing from the bulk samples to the confined ones, revealing, in particular, a thermal stabilization of the disordered longitudinal acoustic mode induced by interaction of EG molecules with the active silanol (Si–OH) groups of the surface.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call