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Posted: August 9, 2010
Queen's University in Canada Selects Linkam Temperature Stages to Characterize Ferroelectric Liquid Crystals
(Nanowerk News) Market leaders in temperature controlled microscopy, Linkam Scientific Instruments, have been used as temperature stage suppliers to Queen's University in Canada for ten years to study the properties of ferroelectric liquid crystals.
The research program of Professor Robert Lemieux and his Kingston, Ontario- based team focuses on the rational design of chiral and achiral molecular components of ferroelectric liquid crystal mixtures based on principles of self-assembly and molecular recognition.
Understanding the thermal properties of liquid crystals is crucial to the establishment of structure-property relationships that are useful in the design of new materials with improved properties. For example, in the design of 'de Vries-like' liquid crystals, the focus is on changes occurring at the SmA-SmC phase transition, both in terms of the order of the phase transition as well as changes in physical properties such as birefringence. As such, the use of thermal polarized optical microscopy allows the observation of texture changes at the SmA-SmC phase transition that provides useful information on such changes, and the Linkam LTS-350 hot stage used provides precise temperature control for this purpose.
The design of the LTS-350 hot stage also makes possible the integration of thermal polarized optical microscopy with the automated Liquid Crystal Analysis System (LCAS-1) by LC Vision in a convenient, turn-key fashion. This is used to measure the spontaneous polarization and optical tilt angle of ferroelectric SmC* liquid crystals induced by a variety of chiral dopants. These measurements are normally performed as a function of temperature using the LTS-350 hot stage.
The Linkam Liquid Crystal Pro system is in use by scientists all over the world. Leading academic and industrial research scientists have made the LTSE350 their preferred choice because of the high degree of control of heating rates, accuracy and long term stability for temperature controlled studies using light microscopes and other spectrometer platforms. It is optimised for liquid crystal sample analysis having fast heating rates up to 30°C/min and excellent thermal stability over the range from -196°C to 350°C. The stage consists of a large area temperature controlled element with a 100 Ohm platinum resistor sensor embedded close to the surface for accurate temperature measurements. It may be operated with Linksys32 DV Imaging software and a QICAM digital camera to provide fully indexed images at predefined points in the temperature profile. For a completely integrated solution, the system can be used with the Linkam Imaging Station to provide an ergonomic platform for ea sy sample handling without the need for a stand-alone optical microscope.