Nanotubes: Small 19/2009

The cover image illustrates a simulation assembly composed of a boron nitride nanotube 6.9 Å in diameter, a 14-Å-thick silicon nitride membrane (shaded), water molecules, and sodium (yellow) and chloride (blue) ions. Molecular dynamics simulations are conducted to determine the force experienced by ions and water molecules as they attempt to move through the nanotube. In response to the pressure applied across the membrane, water ions flow rapidly across the tube, while sodium and chloride ions are effectively rejected, even when the ionic concentrations in the reservoir are increased to twice that of seawater. The speed of water flow across the nanotube is comparable to that of biological water channels or aquaporins. For more information, please read the Full Paper “Salt Rejection and Water Transport Through Boron Nitride Nanotubes” by T. A. Hilder et al., beginning on page 2183. The image was created by Rhys Hawkins of the ANUSF.