Silicon carbide nanotube as a chloride-selective channel

Using several computational techniques, we examine the conduction of water and ions through single-wall nanotubes of various radii, constructed from silicon carbide (SiC). In particular, using classical molecular dynamics, we examine the rate of water and ion conduction through the (5, 5), (6, 6), and (7, 7) SiC nanotubes 36 Å in length. We then determine the current-voltage-concentration profiles using distributional molecular dynamics. The (5, 5) SiC nanotube rejects all ions and conducts water an order of magnitude faster than aquaporin and current reverse osmosis membranes. As expected, the water conduction is shown to increase with increasing diameter, but ions are no longer rejected. In fact, the (6, 6) and (7, 7) SiC nanotubes are shown to be chloride-selective with a conduction of 4.1 and 6.2 pA, respectively, under an applied potential of 200 mV.