Autoassemblies of α-Cyclodextrin and Grafted Polysaccharides: Crystal Structure and Specific Properties of the Platelets

Cyclodextrins (CDs) are a family of oligosaccharides with a toroid shape, which exhibit a remarkable ability to include guest molecules in their internal cavity, providing a hydrophobic environment for poorly soluble molecules. Recently, new types of inclusions of α CDs with alkyl grafted polysaccharide chains (pullulan, chitosan, dextran, amylopectin, chondroitin sulfate...) have been prepared which are autoassembled into micro- and nanoplatelets. We report in this paper an extensive investigation of platelets with different compositions, including their reversible hydration (thermogravimetric analysis), crystalline structure (powder X-ray diffraction), dimensions and shapes (scanning electron microscopy-field emission gun), thermal properties, solubility, and melting (micro-differential scanning calorimetry). The crystalline platelets exhibit layered structures intercalating the polysaccharide backbones and CD complexes hosting the grafted alkyl chains. The monoclinic symmetry of columnar-type crystals ...