Strain-induced violation of temperature uniformity in mesoscale liquids

Eni Kume (1) , Patrick Baroni (1) , Laurence Noirez (1)

1 NFMQ - LLB - Nouvelles frontières dans les matériaux quantiques

Thermo-elasticity couples the deformation of an elastic (solid) body to its temperature and vice-versa. It is a solid-like property. Highlighting such property in liquids is a paradigm shift: it requires long-range collective interactions that are not considered in current liquid or viscoelastic descriptions. We present pioneering studies providing evidence for such solid-like correlations. We will show that ordinary liquids (glycerol, Polypropylene glycol...) emit a modulated thermal hot and cold signal when applying a low frequency (Hz) mechanical shear stress (Figure 1) [1]. The thermal wave reaches a sizable amplitude. As consequence, the liquid converts the energy of shear waves in non-uniform thermodynamic states. These dynamic thermal changes support the hypothesis of the excitation of macroscopic shear elasticity which range is limited to small scale, in accordance with recent nonextensive theoretical models [2,3] and the identification of the generic sub-millimeter shear elasticity revealed in polymer melts, glass formers, ionic liquids and molecular liquids a couple of years ago [4].

Domaines: Matière Molle [cond-mat.soft]

Eni Kume, Patrick Baroni, Laurence Noirez. Strain-induced violation of temperature uniformity in mesoscale liquids. Joint European Thermodynamic Conference, Jun 2021, Prague (virtual), Czech Republic. ⟨hal-03296959⟩