LAUSR

Significance Typically, as the channel length increases, the flow rate decreases due to the increase in flow resistance. Based on molecular dynamics simulations, we show that the pressure-driven flow rate of water through narrow-diameter carbon nanotubes (CNTs) exhibits anomalous transport behavior, whereby the flow rate increases markedly first and then either slowly decreases or changes slightly as the CNT length increases. This anomalous transport behavior of water cannot be simply explained by the tube-length dependence of the free energy barrier for a single water molecule passing through the CNTs; rather, it can be attributed to the tube-length–dependent stability of the cross–CNT orifice hydrogen bonds that formed between water molecules inside and outside the CNT.