  We show using molecular dynamics simulation that spatial confinement of water
inside carbon nanotubes (CNT) substantially increases its boiling temperature
and that a small temperature growth above the boiling point dramatically raises
the inside pressure. Capillary theory successfully predicts the boiling point
elevation down to 2 nm, below which large deviations between the theory and
atomistic simulation take place. Water behaves qualitatively different inside
narrow CNTs, exhibiting transition into an unusual phase, where pressure is
gas-like and grows linearly with temperature, while the diffusion constant is
temperature-independent. Precise control over boiling by CNT diameter, together
with the rapid growth of inside pressure above the boiling point, suggests a
novel drug delivery protocol. Polar drug molecules are packaged inside CNTs;
the latter are delivered into living tissues and heated by laser. Solvent
boiling destroys CNT capping agents and releases the drug.
