Time-resolved light scattering of the phase separation in polymer-dispersed liquid crystals formed by photo-polymerization induced phase separation

Time-resolved light scattering is utilized to monitor the phase separation of photo-initiated polymer-dispersed liquid crystals. At the lowest cure intensities studied, the system undergoes spinodal decomposition and the results are analyzed with Cahn-Hilliard theory. As the cure intensity increases, the rate of phase separation increases such that the early stages of spinodal decomposition are no longer observable. These systems are analyzed using the Debye-Bueche model, which provides the time evolution of the number and size of LC domains. These results indicate that an increase in cure beam intensity initially increases the rate of domain growth, but this effect is overwhelmed by the fast vitrification and cross-linking that can occur at highest cure beam intensities. (c) 2006 Elsevier Ltd. All rights reserved.