In situ multiphase fluid experiments in hydrothermal carbon nanotubes

Hydrothermal multiwall closed carbon nanotubes are shown to contain an enca psulated multiphase aqueous fluid, thus offering an attractive test platfor m for unique in situ nanofluidic experiments in the vacuum of a transmissio n electron microscope. The excellent wettability of the graphitic inner tub e walls by the aqueous liquid and the mobility of this liquid in the nanotu be channels are observed. Complex interface dynamic behavior is induced by means of electron irradiation. Strong atomic-scale interactions between the entrapped liquid phase and the wetted terminated graphite layers are revea led by means of high-resolution electron microscopy. The documented phenome na in this study demonstrate the potential of implementing such tubes in fu ture nanofluidic devices. (C) 2001 American Institute of Physics.