0000000000388067
AUTHOR
H. Skupin
Ordering and mobility of ferroelectric liquid crystal dimer as studied by FT-IR spectroscopy with 2D-IR correlation analysis
Both a conservative rapid-scan FT-IR technique and a novel step-scan FT-IR technique with 2D correlation analysis were used to study the orientation and the mobility ofa ferroelectric liquid crystal dimer during switching under an electric field. The detailed mutual arrangements of different molecular segments (mesogen, poly(methylene) chain, polysiloxane chain) in a smectic C* phase were derived from the static spectra. It was shown that the long mesogen axis, the average poly(methylene) and the average polysiloxane chain axes do not coincide with each other. The hindered rotation of the carbonyl group is confirmed. Time-resolved FT-IR technique was used to follow the segmental motion with…
Giant lateral electrostriction in ferroelectric liquid-crystalline elastomers
Mechanisms for converting electrical energy into mechanical energy are essential for the design of nanoscale transducers, sensors, actuators, motors, pumps, artificial muscles, and medical microrobots. Nanometre-scale actuation has to date been mainly achieved by using the (linear) piezoelectric effect in certain classes of crystals (for example, quartz), and 'smart' ceramics such as lead zirconate titanate. But the strains achievable in these materials are small--less than 0.1 per cent--so several alternative materials and approaches have been considered. These include grafted polyglutamates (which have a performance comparable to quartz), silicone elastomers (passive material--the constri…
Time-Resolved Fourier-Transform Infrared Spectroscopy on the Inter- and Intramolecular Orientational Dynamics in Ferroelectric Liquid Crystalline Dimers
On a base of time-resolved step-scan IR-spectroscopy data, we present a detailed model of the segmental reorientation during the ferroelectric and electroclinic switching of a chiral liquid crystalline dimer. We detected that the magnitude of the motion of the molecular segments differ from each other: The tilt angle is maximal for the mesogens and minimal for the ``virtual polysiloxane backbone.'' In contrast to a recently published conjecture, we prove that in the \ensuremath{\mu}s scale the responses of different molecular segments are unambiguously synchronous with each other.