Orientation of Liquid Crystals by Heat Conduction

Abstract

This is a new phenomenon in heat conduction in which the "liquid crystals" of para-azoxyanisol acquire a preferred orientation under the action of heat conduction in the liquid. A temperature gradient of but 1° or 2°C per cm, at a temperature of approximately 125°C, is sufficient to give a marked effect. The orientation is indicated by the variation in intensity in the x-ray diffraction halo. Both the effect and its magnitude are rather surprising, and it is anticipated that the explanation may rest in the dominance of acoustic waves of inertia and viscosity in heat conduction in liquids, as described by Lucas.