Optical Effects and Molecular Ordering in Spherulites

Abstract

The optical behaviour of spherulite textures exhibited by mixtures of cholesteryl acetate and cholesteryl ethyl carbonate is investigated. The observed optical effects arise due to a helicoidal arrangement of the molecules along the radial directions of the spherulites, the long axes of the molecules being oriented transverse to the radial directions. The helicoidal nature of the structure is strikingly demonstrated by two sensitive interference experiments wherein sinusoidal interference fringes are observed. The observed results are in agreement with the theory developed for the interference effects.