Ultralarge Nanosheets Fabricated by the Hierarchical Self-Assembly of Porphyrin-Ended Hyperbranched Poly (ether amine) (TPP-hPEA)

Abstract

An ultralarge sheet with remarkable lateral dimensions of 10 µm × 10 µm-20 µm × 20 µm is fabricated by the hierarchical self-assembly of porphyrin-ended hyperbranched poly(ether amine) (tetraphenylporphyrin (TPP)-hPEA) in solution. The obtained TPP-hPEA amphiphiles can self-assemble from ultrathin single-layered nanosheets with a thickness of 4 nm to ultralarge multilayered nanosheets with thicknesses from 30 to 70 nm. The lateral dimensions increase from 2 × 2 µm to 5 × 5 µm, and eventually to 10 × 10 µm. In-situ dynamic light scattering and UV-vis spectroscopy studies suggest a hierarchical growth self-assembly mechanism with a self-assembly process that relies on π-π stacking. This 2D self-assembly method provides a significant potential guide for the preparation of ultralarge nanosheets in solution.

Keywords: hierarchical self-assembly; hyperbranched polymers; porphyrins; ultralarge nanosheets.