Relative Permittivity Measurements of Gaseous, Liquid, and Supercritical Dimethyl Ether

Abstract

The relative permittivity (εr) of dimethyl ether (DME) was measured as a function of temperature and pressure in the gaseous, liquid, and supercritical states. The temperature and pressure ranges studied were (303 to 403) K and (0.04 to 33.2) MPa, respectively. The relative permittivity was fitted to the reduced density (ρr) using the function (εr − 1)/(2εr + 1), and the apparent dipole moment (μ*) of the liquid phase was calculated using Kirkwood's theory of molecular polarizability.