Large elastic deformation of C60 nanowhiskers

Abstract

Nano- and micro-crystals of fullerenes of C60 and C70 have been attracted much interest due to their optical and electrical properties. However, molecular crystals such as crystalline fullerenes are generally fragile or brittle due to the weak van der Waals interaction. The mechanical toughness with the elastic deformation is required for the practical applications. Here we show large elastic deformation of C60 nanowhiskers (C60NWs) grown by liquid-liquid interfacial precipitation method using toluene, m-xylene and mesitylene as good solvent. The elastic properties are examined by the bending deformation. The bending behavior strongly depends on the kind of solvent used in the crystal growth. The C60NWs with m-xylene and mesitylene exhibit large elastic deformation, whereas ones obtained by using toluene become brittle showing no large deformation in air. It is shown that the large elastic deformation is attributed to the solvated structure or the solvent in the crystals which plays a crucial role as interlocking and buffering of molecules for the bending deformation.