(670b) Influence of Ionic Liquids on Polymer Nanostructure Formed within Lyotropic Liquid Crystalline Templates

Development of nanostructured polymers utilizing self-assembled lyotropic liquid crystals (LLCs) templates and photopolymerization allows for tailoring and enhancement of material properties not attainable in traditional polymers. However, the thermodynamically driven phase separation between the polymer and LLC templates is typically difficult to avoid. In this study, we investigate a promising method to control hydrogel nanostructure utilizing imidazolium ionic liquids in concert with modulating the light intensity used in photopolymerization. Polymer structure was characterized through polarized light microscopy and small angle X-ray scattering to examine the degree of LLC nanostructure retention during photopolymerization . The light intensity directly affected the degree of LLC mesophases transferred to the final polymer during polymerization. Small changes in light intensity altered dramatically the polymerization behavior of the polyacrylamides which consequently resulted in greater degrees of order retention. Examination of water uptake properties showed significant enhancements for the templated systems as compared to their isotropic counterparts. In addition, the effect of crosslinking density has been explored regarding the retention of LLC order and alterations on the polymerization kinetic behavior. At intermediate crosslinking concentrations the polymerization rate increases, transferring successfully the template order to the final polymer. These results reveal a new method to control and retain nanostructure of a polymer during polymerization that can be valuable in the development of polymers with unique properties not accessible in typical bulk materials or polymer blends.