Textures and Instabilities in Liquid Crystals and Mesomorphic Polymers

Abstract

An aromatic polyester of monomeric units similar to PAA separated by flexible spacers show electrohydrodynamic instabilities in external electric field. As in the case of small molecule liquid crystals, conductive and dielectric modes are observed using polarizing microscopy. Slow kinetics due to the higher viscosity allow the observation of the evolution to turbulence. A new periodic texture in the dielectric domain with a frequency dependent periodicity is also observed in polymeric samples The Freedericksz transition in the case of homeotropic anchorage is discussed.