Self-Assembly of Two-Dimensional Nanosheets Induced by Interfacial Polyionic Complexation

Significant progress has been made during the past decade in preparing nanosheets from a wide range of materials, which are actively pursued for various applications such as energy storage, catalysis, sensing, and membranes. One of the next critical challenges is developing a robust and versatile assembly method which allows construction of the nanosheets into functional structures tailored for each specific purpose. An interesting characteristic of nanosheets is that they often behave as charged macromolecules and thus can readily interact with an oppositely charged polyelectrolyte to form a stable complex. In this report, we demonstrate how such a complexation process could be utilized for directing the self-assembly of nanosheets. By confining the nanosheet-polyelectrolyte complexation at air-liquid or liquid-liquid interfaces, the nanosheets are successfully assembled into various mesoscale architectures including fibers, capsules, and films. Furthermore, incorporation of additional components such as nanoparticles or small molecules can be easily achieved for further tailoring of material properties. This novel assembly method opens a pathway to many useful nanosheet superstructures and may be further extended to other types of nanomaterials in general.