In situ polarized micro-Raman investigation of periodic structures realized in liquid-crystalline composite materials

In situ polarized micro-Raman Spectroscopy has been utilized to determine the liquid crystal configuration inside a periodic liquid crystalline composite structure made of polymer slices alternated to films of liquid crystal. Liquid crystal, Norland Optical Adhesive (NOA-61) monomer and its polymerized form have been investigated separately. The main Raman features, used as markers for the molecular orientation estimation, have been identified. In situ polarized Raman spectra indicate that the orientation of the liquid crystal director inside the structure is perpendicular to its polymeric slices. Results show the usefulness of in situ polarized micro-Raman spectroscopy to investigate liquid crystalline composite structures.