The ability to arrange and precisely organize inorganic nanoparticles into arrays is a requirement for many functional nanosystems, as well as for various electronic and optoelectronic devices that use nanomaterials. A lot of strides have been made over the last few years, but more work still needs to be done to generate highly ordered arrays over long length scales.

Wei Jang and Yutian Zhu, Chinese Academy of Sciences, Jilin, China, Jintao Zhu, Huazhong University of Science and Technology (HUST), Hubei, China, and colleagues have directed gold nanoparticles into long order arrays using block copolymer nanosheets. The gold nanoparticles were created using wet chemical methods and functionalized using a multi-step ligand exchange method. The block copolymers were created via an emulsification reaction. A subsequent collapsing of the emulsion droplets causes a self-assembly approach to happen—where a hexagonally packed cylindrical pattern of a block copolymer was generated for use as a scaffold. These scaffolds were then used to direct the growth of the gold nanoparticles.

The researchers created arrays up to tens of microns in length. They could create multiple architectures, including honeycomb structures and nanoring arrays, as well as hierarchies that combine the two. According to the researchers, this is another tool to use when building large scale nanoparticle arrays.

• Well-Ordered Inorganic Nanoparticle Arrays Directed by Block Copolymer Nanosheets,
  Nan Yan, Xuejie Liu, Jintao Zhu, Yutian Zhu, Wei Jiang,
  ACS Nano 2019.
  https://doi.org/10.1021/acsnano.9b00940