Abstract

In order to provide a firmer base for efforts to interpret the different fragilities of liquids (i.e., the different deviations from simple Arrhenius temperature dependence of relaxation processes), a new and simple one-scan method of quantifying fragility is described and verified. It is based on detecting, by simple differential thermal analysis (DTA), the temperature of maximum energy dissipation during temperature scanning under single-frequency excitation (electrical or mechanical) of the liquid. The frequency is chosen so that the DTA signal indicates directly not only Tg but also the temperature T1/2 (where the relaxation time reaches 10-6 s) of the new and unambiguous fragility metric F1/2,1 which is defined by F1/2 = 2(Tg/T1/2) − 1. The measurement is verified against dielectric data for liquids of widely varying fragility. The usefulness of such rapid scan methods in confirming or denying a vibrational density of states origin of fragility in liquids is considered.

Full Text
Paper version not known

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

Disclaimer: 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.