Heat transfer at the nanoscale: evaporation of nanodroplets

Phys Rev Lett. 2008 Feb 8;100(5):055701. doi: 10.1103/PhysRevLett.100.055701. Epub 2008 Feb 8.

Abstract

We demonstrate using molecular dynamics simulations of the Lennard-Jones fluid that the evaporation process of nanodroplets at the nanoscale is limited by the heat transfer. The temperature is continuous at the liquid-vapor interface if the liquid/vapor density ratio is small (of the order of 10) and discontinuous otherwise. The temperature in the vapor has a scaling form T(r,t)=T[r/R(t)], where R(t) is the radius of an evaporating droplet at time t and r is the distance from its center. Mechanical equilibrium establishes very quickly, and the pressure difference obeys the Laplace law during evaporation.