Two-Dimensional Polymers: Synthesis and Applications

Two-dimensional (2D) polymers represent an emerging class of nanomaterials possessing covalent sheet-like morphology. They display a set of intriguing properties, including large specific surface area, low density, versatile control over sizes and compositions, and high adaptability. As such, they find application in energy conversion and storage, nanotechnology, and biotechnology. However, it remains challenging to synthesize thin-layer 2D polymers with conventional methods. Herein, in this perspective, recent advances in synthesis and applications of thin-layer 2D polymers via capitalizing on various "top-down" and "bottom-up" strategies are summarized. Particularly, some new methods (e.g., free radical polymerization in solution and surfactant-monolayer-assisted interfacial synthesis) in combination with electrostatic repulsion or steric hindrance effect to engineer single-layer 2D polymers at large scale are highlighted.