POLY 123 |
| Recently, lyotropic liquid crystals (LLC) systems have generated significant interest for the creation of new organic nanomaterials because of the nanometer size scale structures that they form. Polymerizable versions of these systems enable to creation of new nanostructured materials by fixing the original structure using covalent bonds. In this study the effect of crosslinking and the light intensity used in the photopolymerization process on the resulting polymer structure is examined. By adding a crosslinking agent of medium polarity to the hexagonal phase of a quaternary ammonium methacrylated surfactant salt and by polymerizing at low intensity, the pore size (as determined by SEM) of the resulting polymer decreases by a factor of 3. Polymerizing at high intensity decreases the pore size by a factor of more than 30. Also, through examination of d-spacing of the primary peak in the SAXS profiles indicates shrinkage of the hexagonal structure at low intensity and expansion at high intensity. This behavior may be due to different dynamics in the reaction process. Finally, the structures and pore sizes of the obtained polymers do not appear to be a direct template of the original LLC phase. Possible causes for this are demixing processes due to thermodynamic factors during polymerization and sample preparation. These results indicate that the kinetics of the polymerization process is a very important variable to take into account when studying structure evolution of polymerizable surfactants. |
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General Papers: Polymers in Nanotechnology
6:00 PM-8:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster
Sci-Mix
Division of Polymer Chemistry |