Liquid crystals dispersed in thermosetting polymer matrices: Molecular, morphological and thermo-optical analysis

A first molecular, morphological and thermo-optical characterisation of a new type of Polymer Dispersed Liquid Crystal (PDLC) is presented. The chemical and structural properties are investigated by transmission FT-IR spectra. The photo-polymerisation process is analysed with optical monitoring, in order to obtain the best curing conditions. An experimental study on the transmittivity as a function of the temperature shows a self-transparency effect, which occurs near the phase transition. An interpretation of the experimental results in terms of a nonlinearity of thermal origin is given, using the theory of nonlinear scattering in heterogeneous media. The temperature switch, obtained in such a condition, suggests the possibility of employing such a material to realise a new type of all-optical temperature sensors and open the horizon to a new class of thermo-optical devices.