Pressure-driven water infiltration into carbon nanotube: The effect of applied charges

Pressure-driven liquid infiltration into hydrophobic nanoporous solids has important applications for energy absorption. Using water infiltration into a carbon nanotube as a model system, here we show from molecular dynamics simulation that with applied charges, the effective degree of hydrophobicity can be increased, which leads to an improved adjustability of energy absorption efficiency. The attractions exerted by the charges can facilitate initial water infiltration, but they may also stick the molecules and effectively block the pathways of subsequent water entrance. Higher pressure is thus needed to infiltrate water into the tube when external charges (or electrical fields) are applied. © 2008 American Institute of Physics.