Internal surface, orientational order, and distribution of a polymer network in a liquid crystal matrix

Abstract

Optical birefringence of the liquid crystal induced in its isotropic phase by low concentration polymer networks (1--4 % by weight) is used to estimate the internal surface area of the network and its order parameter. The results show conclusively that the polymer networks are finely distributed down to the nanometer scale with the orientational order parameter being an order of magnitude smaller than that of the nematic medium where they are formed. A model structure is presented where molecular fibrils form bundles (relatively rich in polymer) which are responsible for the observed inhomogeneities on the submicrometer scale.