Structural characterization of the fullerene nanotubes prepared by the liquid–liquid interfacial precipitation method

Abstract

Fine tubular fibers composed of C 60 and C 70 fullerene molecules were successfully fabricated by the liquid-liquid interfacial precipitation method. The walls of the tubular fibers were crystalline, and the fullerene molecules were densely packed along the growth axis of tube wall. The tubular structures are called "fullerene nanotubes." The inner diameter and the outer diameter of C 70 tubes showed a linear relationship, suggesting a constant wall thickness of the tubes. The tubular structures composed of C 70 molecules could be formed when their diameter was larger than about 240 nm. The fullerene tubes were successfully fabricated by using a C 60 -C 70 soot as well. The formation of fullerene nanotubes can be understood by assuming a mechanism of core dissolution of the solvated fullerene nanowhiskers.

Characterization of fullerene nanotubes prepared by the liquid–liquid interfacial precipitation method

“…The average wall thickness of the C 70 nanotube of Fig. 2 is 112G36 nm which is very close to the wall thickness of 113G18 nm of the C 70 nanotubes prepared by use of IPA [11]. Although this result suggests that the wall thickness of C 70 nanotubes has similar values and does not depend on the kind of alcohol, more data is necessary to confirm the result, testing various alcohols other than IPA and IBA.…”

“…1. By an X-ray diffraction experiment, the as-prepared C 70 nanotubes were found to have a face-centered cubic (fcc) structure with a lattice constant of aZ1.495G0.015 nm [11] which is very close to the lattice constant aZ1.4974 nm of C 70 crystals measured at 93 8C [12]. This fact indicates that C 70 molecules are randomly rotated in the C 70 nanotube walls.…”

“…The orthorhombic structures in Table 1 that are derived from the HRTEM-FFT patterns are different from the fcc structure of C 70 nanotubes that is derived from their XRD measurement [11]. It is conjectured that the crystal structure of the C 70 nanotube was distorted from the initial fcc structure by irradiation of high-energy electron beam and became closer to the orthorhombic structure through an orientational ordering of C 70 molecules.…”

“…2) Heat-treated C 70 nanotube ( Fig. 7) As-prepared C 70 nanotube by use of IPA [11] Orth II [15] a (nm) shrinkage of inside solvated matrix during the heat treatment. It is assumed that the solvated inside cores of initially formed C 70 nanowhiskers are soft and redissolved into the solution to form the tubular structure of C 70 .…”

“…Further, recently we have successfully prepared the nanotubes composed of C 70 molecules and the structural characteristics of as-prepared C 70 nanotubes were presented [11]. The as-prepared C 70 nanotubes had red Science brownish and metallic colour as shown in Fig.…”