Probing structure and dynamics in liquid crystalline microdomains by infrared spectroscopy

While infrared spectroscopy is employed generally to characterize various physical phenomena, spectroscopic applications to macromolecular-liquid crystal (LC) composites have been limited to obtaining LC phase transitions and orientation information. We employ both Fourier transform infrared (FTIR) spectroscopy and FTIR spectroscopic imaging to delineate quantitatively the formation, microstructure and molecular dynamics within a flexible polymer-LC composite. Specifically, phase diagrams, molecular orientational and conformational order and transient molecular reorganizations of the LC upon application of an electric field are determined. The flexible and electrically unresponsive macromolecular component is found to be a dynamic entity during the nematic phase organization and reorientation processes demonstrating the necessity of including polymer segmental contributions to both phase separation and LC dynamics studies. Published by Elsevier B.V.