Nanomaterials to the core
Nanomaterials with a core and a shell made from the same material have been synthesised for the first time.
In previous methods the core and shell parts of these so called core/shell nanomaterials have been made from different materials. But now Jyongsik Jang and colleagues from Seoul National University, Korea, have produced a polypyrrole core/shell nanomaterial using a simple microemulsion polymerisation method.
By utilising the different chemical oxidation potentials of two oxidants the team can produce a spherical material with a linear polypyrrole core and a cross-linked polypyrrole shell. It is easy to fine tune the core diameter and wall thickness of the nanospheres by manipulating the amounts of the surfactant and the monomer used in the synthesis.
Jang and his team use the core/shell nanospheres to produce polymer nanocapsules by performing a simple one-step etching process. They can then carbonise the product to form carbon nanocapsules.
The future for these nanocapsules looks good, and Jang hopes that they will have applications in drug delivery, encapsulation and catalysis.