Web Release Date: November 16,
Supramolecular Ordering of Amide Dendrons in Lyotropic and Thermotropic Conditions
and
Department of Advanced Materials, Hannam University, Daejeon, Korea, Department of Polymer Science and Engineering, Inha University, Incheon, Korea, and College of Materials Science and Engineering, Seoul National University, Seoul, Korea
Received August 1, 2007
In Final Form: September 25, 2007
Abstract:
Self-assembled superstructures of amide dendrons, from first to third generation including monodendrons and covalently linked dimers, were extensively examined, and the supramolecular ordering processes in thermotropic and lyotropic conditions were compared. The superstructures as determined by X-ray diffraction and DSC revealed that the first and second generation dendrons showed nearly identical superstructures regardless of the assembly conditions. But, the third generation dendrons showed a more sensitive self-organizing behavior. The structure obtained from the gel state was lamellar with a more extended conformation, while the structure from the melt state revealed the columnar superstructures of contracted branches. The superstructure formed from the gel state also showed a structural change upon raising the temperature and assumed a structure similar to the thermotropically driven one, implying that the structure formed from the gel is thermodynamically unstable. The formation of lamellar- or cylinder-type superstructures from amide dendrons was primarily dependent on the shape of dendrons, which is associated with the branch size (generation) and the surrounding conditions.
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