[SY-M4] Structural predictor for nonlinear sheared dynamics in simple glass-forming liquids
Glass-forming liquids subjected to sufficiently strong shear universally exhibit striking nonlinear behavior; for example, a power-law decrease of the viscosity with increasing shear rate. This phenomenon has attracted considerable attention over the years from both fundamental and applicational viewpoints [1, 2, 3, 4]. However,
the out-of-equilibrium and nonlinear nature of sheared fluids have made theoretical understanding of this phenomenon very challenging and thus slower to progress. We find here [5] that the structural relaxation time as a function of the two-body excess entropy, calculated for the extensional axis of the shear flow, collapses onto
the corresponding equilibrium curve for a wide range of pair potentials ranging from harsh repulsive to soft and finite. This two-body excess entropy collapse provides a powerful approach to predicting the dynamics of nonequilibrium liquids from their equilibrium counterparts. Furthermore, the two-body excess entropy
scaling suggests that sheared dynamics is controlled purely by the liquid structure captured in the form of the two-body excess entropy along the extensional direction, shedding light on the perplexing mechanism behind shear thinning.
References
[1] D. J. Evans, H. J. M. Hanley, and S. Hess. Phys Today 37, 26 (1984).
[2] R. Yamamoto, and A. Onuki. Phys. Rev. E 58, 3515 (1998).
[3] V. Lubchenko. Proc. Natl. Acad. Sci. U.S.A. 106, 11506 (2009).
[4] X. Cheng, J. H. McCoy, J. N. Israelachvili, and I. Cohen. Science 333, 1276
(2011).
[5] T. S. Ingebrigtsen, and H. Tanaka. Proc. Natl. Acad. Sci. U.S.A. 115, 87 (2018).
the out-of-equilibrium and nonlinear nature of sheared fluids have made theoretical understanding of this phenomenon very challenging and thus slower to progress. We find here [5] that the structural relaxation time as a function of the two-body excess entropy, calculated for the extensional axis of the shear flow, collapses onto
the corresponding equilibrium curve for a wide range of pair potentials ranging from harsh repulsive to soft and finite. This two-body excess entropy collapse provides a powerful approach to predicting the dynamics of nonequilibrium liquids from their equilibrium counterparts. Furthermore, the two-body excess entropy
scaling suggests that sheared dynamics is controlled purely by the liquid structure captured in the form of the two-body excess entropy along the extensional direction, shedding light on the perplexing mechanism behind shear thinning.
References
[1] D. J. Evans, H. J. M. Hanley, and S. Hess. Phys Today 37, 26 (1984).
[2] R. Yamamoto, and A. Onuki. Phys. Rev. E 58, 3515 (1998).
[3] V. Lubchenko. Proc. Natl. Acad. Sci. U.S.A. 106, 11506 (2009).
[4] X. Cheng, J. H. McCoy, J. N. Israelachvili, and I. Cohen. Science 333, 1276
(2011).
[5] T. S. Ingebrigtsen, and H. Tanaka. Proc. Natl. Acad. Sci. U.S.A. 115, 87 (2018).