Multilayered supramolecular structures: Two-dimensional polymers and polar assemblies
This research project investigated the structure and properties of bulk films created from multilayered supramolecular structures. The rodcoil molecule was key to the formation of two-dimensional layers stacked over macroscopic distances. It consists of a rigid and monodisperse rod-like segment covalently attached to a flexible coil-like segment. The coil-like segments were of narrow molecular weight distribution and contained a diblock sequence of oligomeric styrene and isoprene. Two rodcoil systems were investigated in this project, one contained a liquid crystalline mesogen and a second one contained a rod functionalized with a phenolic end group. We found that the first rodcoil forms long range layered assemblies in solution cast bulk films with nanophase separation of the three chemically distinct segments. These assemblies stack spontaneously on solid substrates over macroscopic distances and form self-assembled surfaces. Moreover, the substrate seems to guide the stacking direction of the layers. Upon thermal crosslinking of the isoprene middle sector, these assemblies yield 2D polymers which should be shape-persistent plate-like molecules. Isolated 2D polymers are stable up to 320$\sp\circ$C, which is at least 143$\sp\circ$C higher than the isotropization temperature of their precursor monomer.
Chemistry, Polymer, Engineering, Materials Science
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign