F. Solá, Z. H. Xia, M. Lebrón-Colón and M. A. Meador
Polymer nanocomposites filled with single wall carbon nanotubes (SWCNTs) are promising materials for aerospace applications. The control of homogeneous dispersion of the nanotubes in the polymeric matrix is important, e.g., for an optimum mechanical response of the nanocomposite. Furthermore, identification of the metallic or semiconducting nature of the nanotubes through chirality is needed. However, imaging SWCNTs in a polymer matrix is challenging both due to the small size and because the contrast is covered by scattering from the polymer matrix. Solá et al. (pp. 349–351) theoretically investigate the high-resolution transmission electron microscopy (HRTEM) images and electron diffraction (ED) of nanovolumes composed of polyethylene filled with SWCNTs using multislice theory and the optics of an FEG TEM at 80 kV. If the electron beam is oriented perpendicular to the nanotube walls, the results strongly depend on the nanocomposite thickness, HRTEM features of the nanofiller can even completely disappear, although chirality (and hence diameter) may be extracted by reflections of the ED pattern. The authors discuss the new limits set up for TEM investigation of dispersion and chirality.