Fig. 4.

TEM micrographs of nanotubes formed from chiral HBC amphiphile (S)-2 in MeTHF (a), ClCy (b), and MeTHF/MeOH (c). For the preparation of samples a and b, suspensions, formed by slow cooling of the hot solutions (1 mg/ml) from 50° to 20°C, were diluted by a factor of 10, applied onto a specimen grid covered with a thin carbon support film, and air-dried. For the preparation of sample c, a MeOH vapor was allowed to diffuse slowly into a dilute MeTHF solution at 20°C, and the resulting suspension was treated similarly to the above.