Photopolymerization kinetics and structure development of templated lyotropic liquid crystalline systems
Polymers and High Performance Materials
The templating of the ordered nanostructures of lyotropic liquid crystals (LLC) onto organic polymers has recently been of great interest. This work describes the polymerization and segregation behavior of polar and nonpolar monomers in an LL(: environment. Nonpolar monomers partition to the oil-soluble domains of the LLC phase, whereas mol e polar monomers segregate at the interface of the liquid crystals. The polymerization kinetics in both cases are significantly influenced by the LLC phase morphologies although in different ways. The nonpolar monomers exhibit the fastest polymerization rates in micellar aggregates. This behavior is a result of an increase in the rate of propagation, induced by higher local concentrations of monomer in the micelles as compared to other mesophases. For more polar monomers, the opposite polymerization behavior is observed. The fastest polymerizations for these monomers are observed in the highly ordered lamellar mesophase with the minimum polymerization rate observed in the isotropic micellar phase. In this case, the enhanced polymerization rates are a consequence of depressed termination rates. This decrease in termination rate is due to diffusional limitations induced by the high degree of order in a lamellar mesophase. Initial results also indicate that the original LLC phase morphologies are retained after photopolymerization.
(2001). Photopolymerization kinetics and structure development of templated lyotropic liquid crystalline systems. MACROMOLECULES, 34(13), 4430-4438.
Available at: http://aquila.usm.edu/fac_pubs/3867