Dielectric study of the motion of molecules in the supercooled liquid state

Abstract

A dielectric study of dilute solutions of small molecules in ortho-terphenyl in the supercooled liquid state shows that their microbrownian motions may occur at 10⁵ to 10¹⁰ s slower than in normal low viscosity solvents. The dielectric loss curves are far broader than a single relaxation time process with an apparent activation energy near 260 kJ mol^–1. The behaviour is consistent with a cooperative process having a dipole moment correlation function which has a natural non-exponential dependence on time. The similarity to solid amorphous polymers is briefly discussed.