Temperature inversion of the thermal polarization of water

Phys Rev E Stat Nonlin Soft Matter Phys. 2015 Dec;92(6):060103. doi: 10.1103/PhysRevE.92.060103. Epub 2015 Dec 30.

Abstract

Temperature gradients polarize water, a nonequilibrium effect that may result in significant electrostatic fields for strong thermal gradients. Using nonequilibrium molecular dynamics simulations, we show that the thermal polarization features a significant dependence with temperature that ultimately leads to an inversion phenomenon, whereby the polarization field reverses its sign at a specific temperature. Temperature inversion effects have been reported before in the Soret coefficient of aqueous solutions, where the solution changes from thermophobic to thermophilic at specific temperatures. We show that a similar inversion behavior is observed in pure water. Microscopically, the inversion is the result of a balance of dipolar and quadrupolar contributions and the strong temperature dependence of the quadrupolar contribution, which is determined by the thermal expansion of the liquid.

Publication types

  • Research Support, Non-U.S. Gov't