Constructing Tunable Hierarchical Nanosheets and Their Application in Polymer Reinforcement

Nanosheet materials are tremendously attractive for their specific planar architecture and large surface area. However, fabricating nanosheet structures with morphological and functional control across spatial domains from the 2D to 3D scale remains a great challenge. Herein, we report a facile one-pot strategy for creating nanosheets with tunable geometries and multilevel hierarchies based on a liquid crystalline (LC) block copolymer. By finely tuning the assembly conditions, a variety of nanosheet morphologies were achieved, including multilayer leaf-like nanosheets (MLNs), multilayer rectangular nanosheets (MRNs), 3D stacked leaf-like nanosheets (SLNs), 3D stacked rectangular nanosheets (SRNs), and stacked flower-like nanosheets (SFNs). The formation of diverse nanosheet structures relies on LC ordering and the nucleation and growth tendencies of the copolymer. Particularly, we demonstrate that these hierarchical nanosheets are promising additives for polymer reinforcement. By mimicking biological reinforcing principles, SLNs integrating a large surface area with layered and anisotropic characteristics exhibit efficient toughening and strengthening effects through effective energy dissipation and crack deflection. This study not only offers a facile strategy for the design of nanosheet materials with precise control of their morphologies and dimensions but also provides new insight into using hierarchical nanosheet structures to achieve advanced polymer performance.