Supramolecular Nanostructures of Structurally Defined Graphene Nanoribbons in the Aqueous Phase

Abstract

Structurally well‐defined graphene nanoribbons (GNRs) have attracted great interest because of their unique optical, electronic, and magnetic properties. However, strong π–π interactions within GNRs result in poor liquid‐phase dispersibility, which impedes further investigation of these materials in numerous research areas, including supramolecular self‐assembly. Structurally defined GNRs were synthesized by a bottom‐up strategy, involving grafting of hydrophilic poly(ethylene oxide) (PEO) chains of different lengths (GNR‐PEO). PEO grafting of 42–51 % percent produces GNR‐PEO materials with excellent dispersibility in water with high GNR concentrations of up to 0.5 mg mL⁻¹. The “rod–coil” brush‐like architecture of GNR‐PEO resulted in 1D hierarchical self‐assembly behavior in the aqueous phase, leading to the formation of ultralong nanobelts, or spring‐like helices, with tunable mean diameters and pitches. In aqueous dispersions the superstructures absorbed in the near‐infrared range, which enabled highly efficient conversion of photon energy into thermal energy.