Molecular dynamics in low-molar and polymeric ferroelectric liquid crystals

Broadband dielectric spectroscopy covering the frequency range from 10−1 Hz to 109 Hz was employed to study the molecular dynamics in low-molar and polymeric ferrroelectric liquid crystals. At frequencies below 106 Hz the ferroelectric modes, soft and Goldstone mode are observed. In the frequency regime from 106 Hz to 109 Hz a fast relaxation process is found, which is assigned to the hindered rotation of the mesogens around their long molecular axis. It turns out that the molecular dynamics is not principally different between low-molar and polymeric systems.

LC-Polymers with Axial Chirality

Abstract Liquid crystalline polymers with axial chirality are prepared. These polymers are chiral, not due to a single asymmetric carbon atom, but due to a larger molecular fragment, which is chiral as a whole. They exhibit cholesteric and chiral smectic C* phases. Dielectric spectroscopy proves strong ferroelectric properties in the chiral smectic C* phases of these polymers.

Molecular dynamics in ferroelectric liquid crystals: From low molar to polymeric and elastomeric systems

Ferroelectric liquid crystalline polysiloxanes with high spontaneous polarization and possible applications in nonlinear optics

Structural defects in smectic c* liquid crystals

In this paper the structure of a smectic c* liquid crystalline material which can be switched in an electric field is investigated by electron microscopic techniques. Using this method the director field is revealed and typical disclinations observed. Analysis of these features enables the elastic anisotropy of the material to be calculated. Sample description. For our structure investigations a liquid crystalline material (4-(3-(s)-methyl-2-(s)-chloropentanoyloxy)-4'-octyloxy-biphenyl) with two chiral centres was synthesised using known procedures [I]. This material has been investigated by broadband dielectric spectroscopy, the softand Goldstone modes were analysed [2a] as well as the hig…