Authors: S.M. Shang
Affilation: The Hong Kong Polytechnic University, Hong Kong
Pages: 274 - 276
Keywords: polypyrrole-cycledextrin (PPy-CD) nanospheres, core-shell structure, uniform nano-size
The delivery of unique nanospheres has aroused wide attention due to the potential applications in optical, electrical, magnetic, and biological devices. Special attention has recently been paid to the methods for controlling the size and distribution of nanospheres, because these properties would significantly influence the application of nanospheres in the above mentioned advanced devices. Even though nanospheres have commonly been produced by the template polymerization and supramolecular self-assembly, effective controlling the size or structure of nanospheres has remained a challenging task. In this paper, we described a facile strategy for fabrication of the polypyrrole-cycledextrin (PPy-CD) nanospheres with a unique core-shell structure. The prepared nanospheres have a uniform nano-size with a narrow size distribution. The nanospheres were successfully synthesized via a simple ultrasonic treatment by mixing pyrrole and β-cycledextrin (β-CD) in the formaldehyde aqueous solution at room temperature, and FeCl3 was added as an oxidant. With the aid of FeCl3, a continuous polypyrrole layer was formed on the surface of β-CD through the oxidative polymerization of pyrrole. These PPy-CD nanospheres were extensively characterized by SEM, TEM, FT-IR, and XRD. It was found that the prepared PPy-CD nanospheres have a clear core-shell nanostructure. Moreover, the morphology of the resulted PPy-CD nanospheres depended not only on the ratio of pyrrole to FeCl3, but also the amount of formaldehyde in the reaction aqueous system. A possible mechanism for the formation of the nanospheres was proposed. To our knowledge, these unique nanospheres with a core-shell nanostructure have not been reported. This method can be easily applied to fabricate the nanoparticles with different geometric shapes if the template materials with the suitable core shapes such as cubes, cylindrical, or polyhedron were obtained.