Composite structure of liquid crystal/polymer nanotubes revealed by high-angle annular dark-field scanning transmission electron microscopy.
We have applied high-angle annular dark-field microscopy to the characterization of the structure of template-grown nanotubes composed of a polymer and a discotic liquid crystalline material. Selective staining of the liquid crystal phase with ruthenium tetroxide was used to develop adequate Z-contrast that allows us to distinguish between the two phases. At appropriate staining conditions, we could clearly visualize, in the annular dark-field mode, a 5-15-nm thin liquid crystalline layer precipitated on the inner surface of the polymer tubes. Cryo-electron diffraction has shown high alignment of the discotic columns within the layer parallel to the tube axis. However, although the polymer/liquid crystal phase separation is almost complete, the wetting behavior of the polymer in relation to the template appears to be sensitively influenced by kinetic factors.
Schaper
Andreas K
AK
Material Sciences Center, Philipps University, Hans-Meerwein-Str., 35032 Marburg, Germany. schaper@staff.uni-marburg.de
Kurata
Hiroki
H
Yoshioka
Taiyo
T
Tsuji
Masaki
M