Abstract
One of the major features of glass forming ultraviscous liquids is the decoupling between translational and orientational dynamics. This paper presents studies of this phenomenon in glycerol, an accepted molecular glass former, concentrating on the impact of two exogenic factors: high pressures (P) up to the extreme 1.5 GPa and silver (Ag) nanoparticles (NPs). The analysis is focused on the fractional Debye-Stokes-Einstein (FDSE) relationship: σ(T,P)(τ(T,P))(S) = const, linking DC electric conductivity (σ) and primary (alpha, structural) relaxation time (τα). In glycerol and its nanocolloid (glycerol + Ag NPs) at atmospheric pressure only negligible decoupling (S ∼ 1) was detected. However, in the compressed nanocolloid, a well-defined transformation (at P = 1.2 GPa) from S ∼ 1 to the very strongly decoupled dynamics (S ∼ 0.5) occurred. For comparison, in pressurized 'pure' glycerol the stretched shift from S ∼ 1 to S ∼ 0.7 took place. This paper also presents the general discussion of FDSE behavior in ultraviscous liquids, including the new link between the FDSE exponent, fragility and the apparent activation enthalpy and volume.
Highlights
Glass transition physics has remained a challenge for condensed and soft matter physics for many decades.[1,2,3] The most intriguing feature is the set of strong previtreous effects for dynamic properties, with similar patterns for qualitatively different glass forming systems.[2]
This paper focuses on the fractional Debye–Stokes– Einstein (FDSE) behavior in the nanocolloid composed of glycerol and Ag NPs
This paper presents the first ever experimental report of FDSE behavior in a nanocolloid–nanocomposite system
Summary
Glass transition physics has remained a challenge for condensed and soft matter physics for many decades.[1,2,3] The most intriguing feature is the set of strong previtreous effects for dynamic properties, with similar patterns for qualitatively different glass forming systems.[2]. The impact of NPs lead to the crossover of the strongly decoupled region in the immediate vicinity of the Tg, i.e., within the ultraviscous domain, a phenomenon which has not been reported before
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
