Gold nanoparticles act as surfactants to control the assembly of block copolymer particles (BCPs) to form convex lens-shaped particles. These unconventionally shaped particles with highly ordered nanoporous channels are generated through emulsion templation and interfacial modulation by gold nanoparticles (Au NPs). The regularly ordered channels also provide a functional space, in which materials can be loaded (e.g., metals and dyes).

Se Gyu Jang, Korea Electric Power Research Institute (KEPRI), Daejeon, Bumjoon J. Kim, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, and colleagues were able to exploit the precise positioning of size-controlled Au NPs at the interface between one block domain (poly(4-vinylpyridine) (P4VP) of the BCPs at the particle surface and the surrounding water to control the structural characteristics of the polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) particles.

Particles containing highly ordered Au rods were prepared by filling the channels with Au, leading to particles with unique optical properties of a microlens. These hold great promise for use in optical, biological-sensing and imaging applications.

• Size-Controlled Nanoparticle-Guided Assembly of Block Copolymers for Convex Lens-Shaped Particles,
  K. H. Ku, J. M. Shin, M. P. Kim, C.-H. Lee, M.-K. Seo, G.-R. Yi, S. G. Jang, B. J. Kim,
  J. Am. Chem. Soc. 2014.
  DOI: 10.1021/ja502075f