Abstract
Nonlinear rheological properties of viscous indomethacin are studied in the frequency range of its structural relaxation, that is, in a range so far inaccessible to standard techniques involving medium-amplitude oscillatory shear amplitudes. The first- and third-order nonlinearity parameters thus recorded using a sequence of small and large shear excitations in a time efficient manner are compared with predictions from rheological models. By properly phase cycling the shear amplitudes, build-up and decay transients are recorded. Analogous to electrical-field experiments, these transients yield direct access to the structural relaxation times under linear and nonlinear shearing conditions. To demonstrate the broader applicability of the present approach, transient analyses are also carried out for the glass formers glycerol, ortho-terphenyl, and acetaminophen.
Original language | English |
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Article number | 134901 |
Journal | Journal of Chemical Physics |
Volume | 155 |
Issue number | 13 |
DOIs | |
State | Published - Oct 7 2021 |
Externally published | Yes |
Funding
We acknowledge the Deutsche Forschungsgemeinschaft, Project Nos. 319140174 and 461147152, for supporting this project financially.
Funders | Funder number |
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Deutsche Forschungsgemeinschaft | 461147152, 319140174 |