Influence of Dispersion in Liquid Crystal on Optical Properties of Cyanine Dye J-Aggregates

Formation of J-aggregates of the cationic cyanine dye PIC in a nematic liquid crystal (LC) matrix 5CB is reported, with analysis of optical-fluorescent and electro-optical properties of the obtained novel material. The PIC J-aggregates in the nematic matrix show worse optical properties compared with them in an aqueous solution but extremely higher photostability. The electro-optical characteristics of the LC matrix are substantially modified, with the Fredericks transition threshold slightly increased, which is, on the other hand, accompanied by the improvement of the optical contrast. Only a minor effect of the forming J-aggregates on the molecular order of the LC structure could be noted.