Synthesis and Electro-Optical Studies on Composite Materials Polymer Particles/Nematic Liquid Crystal

Abstract

We have synthesized polymer particles of the type alternated copolymers DVB- maleic anhydride. The dimensions of the obtained particles have been determined by electron microscopy and are in the range 1–2 μm. These particles have been mixed by stirring and ultrasound with nematic liquid crystals ZLI 1221 (Merck), in a concentration of 5% b.w.(polymer/LC).

We applied cycles of temperature and electric field, corresponding to the TSDC method. We measured the depolarization currents and simultaneously the optical transmission as a function of the electric field and temperature. We obtained information regarding the conduction mechanism, the activation energy and the pre-exponential frequency factor in the Arrhenius diagrams. The dipolar current obtained is consequent to a superposition of a dipolar distribution with a wide spectrum of relaxation times.

Keywords:

• activation energy
• liquid crystal colloidal composites
• optical transmission
• thermally stimulated depolarization currents