Theoretical and experimental investigation of aqueous liquids contained in carbon nanotubes

Abstract

The dynamic response—as caused by different means of thermal stimulation or pressurization—of aqueous liquid attoliter volumes contained inside carbon nanotubes is investigated theoretically and experimentally. The experiments indicate an energetically driven mechanism responsible for the dynamic multiphase fluid behavior visualized in real time with high spatial resolution using electron microscopy. The theoretical model is formulated using a continuum approach, which combines temperature-dependent mass diffusion with intermolecular interactions in the fluid bulk, as well as in the vicinity of the carbon walls. Intermolecular forces are modeled by Lennard-Jones potentials. Several one-dimensional and axisymmetric cases are considered. These include situations which physically represent liquid volume pinchoff, jetting, or fluid relocation due to thermal stimulation by a steady or modulated electron beam, as well as liquid precipitation (condensation) from vapor due to overcooling or pressurization. Comparisons between theoretical predictions and experimental data demonstrate the ability of the model to describe the characteristic trends observed in the experiments.