(70a) Photopolymerization of Reactive Lyotropic Liquid Crystals

Reactive lyotropic liquid crystals (LLC) systems have the potential to be used for nanostructured applications due to their inherent order and nanometer size scale structures. The primary reason that these materials have not been used more extensive is that, due to entropic limitations during the polymerization process, the original LLC order is often not retained. Therefore, before materials with controlled lyotropic structure can be created in a controllable way, the polymerization process needs to be understood. In this study the effect of the aliphatic chain length of the reactive surfactant in the photopolymerization process is examined. Polymerization in hexagonal phases formed from reactive amphiphiles with longer aliphatic tails exhibit lower polymerization rates when compared to systems with shorter aliphatic tails, suggesting that the order of the hexagonal phase decreases as the aliphatic tail increases. Crosslinking enables the retention of a hexagonal phase that is not retained by other means. Also, copolymerization of different reactive surfactants at a fixed total surfactant concentration enables variation of LLC phases while tuning physical properties of the polymer system.