Self-assembling microsized materials to fabricate multifunctional hierarchical nanostructures on macroscale substrates

It is very challenging to assemble microscale objects on a macroscale substrate due to the weak interaction and size/geometric mismatch. Herein a novel polyelectrolyte-mediated self-assembly approach with microsized ZnO nanoflowers as building blocks was successfully used to grow a hierarchical nanostructure on a substrate, which is mainly due to the loop and tail conformation of the weak polyelectrolyte used. Furthermore, a heating step was able to enhance the self-assembly process. The obtained ZnO flower hierarchical nanostructure possesses simultaneous non-light induced superhydrophilic, antifogging and antibacterial properties, thus providing great potential in applications such as biomedical devices, hospital building paints, and daily life uses. This demonstrated method could be extended to fabricate hierarchical nanostructures with other microscale nanostructured materials on various substrates for broad applications.