The regulation of the size and morphology of micro- and nanoscale materials, which can have applications as wide and varied from catalysis, to gas storage to drug delivery, is a key approach to controlling the chemical and physical properties of such materials. The group of Moonhyun Oh, Yonsei University, Korea, has developed a strategy to construct multilayer core–shell structures through a multistep growth method of a variety of coordination polymers.

The chosen core material was carboxylic acid terminated silica particles, which were then coated with the coordination polymer precursors Y(NO₃)₃, Gd(NO₃)₃, or Er(NO₃)₃ in a multistep process to give up to three layers of polymer surrounding the core. By altering the sequence of the polymer precursors used in the multistep growth, the composition of the different layers could be easily controlled. The incorporation of lanthanides into these microspheres could lead to interesting optical properties.

It is envisaged that this method could be applied to a wider variety of polymer precursors and hence the production of many multilayered core–shell particles with diverse compositions.

• Systematic Formation of Multilayered Core–Shell Microspheres through the Multistep Growth of Coordination Polymers,
  J. Son, H. J. Lee, M. Oh,
  Chem. Eur. J. 2013.
  DOI: 10.1002/chem.201300585