Polymer liquid crystals-liquids or crystals

Abstract

Liquid crystals belong to a class of materials which were first described over a hundred years ago as characterising a state of matter intermediate between that of a crystal and a liquid. The light microscopic textures which are observed in these “ordered liquids” are very characteristic and have been described in many text books /1/. During the past decade there has been a resurging interest in these materials because it was recognised that by adding suitably functionalised groups of atoms to organic molecules, a wealth of extremely interesting physical properties could be induced and, to a large extent, manipulated in order to suit a specific purpose. Such properties include mechanical strength as well as ferroelectricity, non-linear optical activity and electronic charge transfer. The physical principles involved are summarised in a number of excellent books /2, 3/.