Small angle light scattering investigation of polymer dispersed liquid crystal composites

The curing of a homogeneous mixture of a nematic liquid crystal and an acrylate UV curable prepolymer was studied by small angle light scattering, varying temperature and UV intensity. For all the conditions except at elevated temperature, the phase separation occurs with a spinodal decomposition which phases can be more or less easily recognised. Whatever the temperature below the clearing point of the liquid crystal and the UV intensity, the isotropic-to-nematic transition that occurs in the liquid crystal rich region is easily seen as a strong decrease of the light scattering intensity. For all the conditions tested, the final morphology is in the form of a droplet morphology. At high UV intensity, there are two scattering peaks that are appearing in the scattering pattern which was tentatively interpreted as a double spinodal decomposition. (C) 2002 Elsevier Science Ltd. All rights reserved.