INFLUENCE OF THE POLYMER MATRIX ON THE BIPOLAR AND RADIAL DROPLET CONFIGURATIONS WITHIN PDLC FILMS EXAMINED BY INFRARED-SPECTROSCOPY

The influence of the polymer matrix on the liquid crystal droplet configuration within a polymer-dispersed liquid crystal (PDLC) film is studied with the use of infrared spectroscopy. With a change of the polymer from poly(n-butyl methacrylate) to poly(isobutyl methacrylate) with the use of E7 liquid crystal, the droplet configuration changes from bipolar to radial. For both of these PDLC systems with 80:20, 70:30, and 60:40 E7/polymer compositions, the LC droplets grow in diameter with time. The spectroscopic data monitoring the droplet growth are described exponentially. A transition temperature is observed as both types of PDLCs cool, forming droplets by the thermally induced phase-separation technique. The T(N-I) transition for the E7/PBMA PDLC appears at 46-degrees-C and for the E7/PIBMA PDLC appears at 51-degrees-C.