Novel Supramolecules Based on Architecturally Variant alpha-Cyclodextrin Polyrotaxanes and Nanorod-Like alpha-Cyclodextrin Self-Assembly
J.W. Chung, B.-Y. Yu and S.-Y. Kwak
Seoul National University, KR
alpha-cyclodextrin, self-assembly, molecular architecture, nanorod, mesopore
Self-assembly (SA-ICs) of architecturally variant alpha-cyclodextrin (alpha-CD) inclusion complexes (ICs) formed by host-guest reaction with four polymeric guest having different molecular architectures (star-shaped, hyperbranched, diblocked, and linear polymer) and nanorod-like self-assembly (SA-CD) of alpha-CD could be successfully synthesized by simple routes such as stirring and sonication in a suitable solvent, respectively. For SA-ICs, It was found that the polymeric guests were well included into the hydrophobic alpha-CD cavity and that all ICs had a columnar-type crystalline structure, irrespective of the PCL molecular architecture. However, clearly distinguishable features were revealed from stoichiometry and morphology because of the structural difference between the ICs attributed to molecular architecture of polymeric guests. In particular, morphology showed that ICs had a hexagonally packed supramolecular structure ascribed to a specific solvent treatment, excepting SA-IC with star-shaped polymeric guests. For SA-CD, it was observed that nanorod-type alpha-CD self-assembly with hexagonally packed columnar crystalline structure similar to the ICs formed with guest molecules was formed by columnar arrangement of alpha-CD, as shown in FE-SEM image. Particularly, FE-SEM image showed that SA-CD had porous structure attributed to the random aggregation of alpha-CD nanorod. From BET analysis, it was also verified that the SA-CD had meso-sized pore.
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Nanotech 2007 Conference Program Abstract