Kun’ichi Miyazawa
National Institute for Materials Science, Japan
Title: Synthesis and photo-polymerization of C60 fullerene nano-whiskers
Biography
Biography: Kun’ichi Miyazawa
Abstract
Fullerene nano-whiskers (FNWs) are thin needle-like crystals with diameters less than 1000 nm, and are composed of fullerene molecules such as C60, C70, Sc3N@C80 and so forth. Among various FNWs, C60 (fullerene) nano-whiskers (C60NWs) have been most minutely investigated in the field of semiconductor devices like field-effect transistors, solar cells, chemical sensors and photo sensors. C60NWs easily become superconductors by doping alkali metals such as K and Rb. The superconducting transition temperature (Tc) of Rb-doped C60NWs is 26 K, which is much higher than the boiling point of hydrogen (20 K). In the future, the Rb-doped C60NWs might be widely utilized as lightweight and flexible super-conductors, using the hydrogen coolant. The FNWs have been normally synthesized by the liquid-liquid interfacial precipitation (LLIP) method. The LLIP method is a very facile technique that utilizes the precipitation and inters diffusion between the good solvent solution of fullerene and its poor solvent.　The as-synthesized C60NWs by LLIP method comprise the C60 molecules weakly bound via Vander Waals bonding forces. However, the C60 molecules can be polymerized by irradiation of light, and the physical and chemical properties of C60NWs can be modified by the light irradiation. In the presentation, the structural characteristics of photo-polymerized C60NWs will be discussed, using high-resolution transmission electron microscopy (HRTEM), EELS and Raman spectroscopy.