No abstract

Crystalline fullerene C60 nanotubes were prepared simply via liquid-liquid interfacial precipitation using the mixture of C60-saturated pyridine and isopropyl alcohol. C60-saturated pyridine solution was exposed to visible light to promote the growth of fullerene C60 nanotubes. The average diameters of the fullerene particles in C60-pyridine colloid solution after irradiation were characterized by dynamic light scattering. After light irradiation, an outer separated layer of pyridine surrounds the fullerene particles because of the charge transfer complexes formation. The mean ratios of inner diameter to outer diameter of fullerene C60 nanotubes fabricated at different irradiation time and wavelength were given in this paper for the first time. On the basis of the relationship between the average diameters of the fullerene particles in C60-pyridine colloid solution and the mean ratio of inner diameter to outer diameter of FNTs fabricated after irradiation, outer separated layer of pyridine surrounding the fullerene particles was supposed to play an important role in the formation process of fullerene C60 nanotubes.

In this paper, we provide a method for the simultaneous measurement of the inner diameter of nanotubes with a regular shape and calculation of their mean inner potential (MIP) using electron holography. This method contains 4 steps: (i)phase profile characterization from electron holography; (ii) shape assumption from prepared data; (iii) thickness simulation from a shape assumption and fitting method; (iv) calculation of MIP of the simulated and fitted parameters. By this method, as an example, the shape and the outer and inner diameters of a tube formed from C(60) molecules were characterized. The MIP of the tube was also calculated through this method. The MIP calculation from another nano whisker formed from C(60) molecules supports the feasibility of our method and it could be extended to other nanomaterials. This work provides a convenient method for morphology characterization of hollow nanomaterials, such as diameter measurements and cross-sectional shape determination, which are the most basic and important characteristics of the nanomaterials. In addition, it also provides a method for MIP calculation without a thickness measurement if the samples have relatively regular shapes. Thus this method should be more convenient for closely combining the tomography and physical properties of samples, which could be essential for in situ TEM studies of nanomaterials.