Electromanipulating Water Flow in Nanochannels†
We thank Prof. Ruhong Zhou for critical comments on the manuscript. This work was supported by the NSFC (11405146, 61274099, 51234007, 51404291, and 51490654), NBRPC (2012CB825700), PCSIRT (IRT1294), Shandong Provincial NSFC (ZR2013DL011), Zhejiang Provincial Science and Technology Key Innovation Team (2011R50012-2) and Key Laboratory (2013E10022). J.Y. acknowledge the Climb Taishan Scholar Program in Shandong Province. J.T.F. was supported by the Start-up fund of Cornell University.
Graphical Abstract
A vibrational charge outside a nanochannel can promote water flux within the channel. A decrease in the distance between the charge and the nanochannel causes an increase in the water net flux, which is contrary to that of the fixed-charge system. This electromanipulating transport phenomenon provides an important new mechanism of water transport confined in nanochannels.
Abstract
In sharp contrast to the prevailing view that a stationary charge outside a nanochannel impedes water permeation across the nanochannel, molecular dynamics simulations show that a vibrational charge outside the nanochannel can promote water flux. In the vibrational charge system, a decrease in the distance between the charge and the nanochannel leads to an increase in the water net flux, which is contrary to that of the fixed-charge system. The increase in net water flux is the result of the vibrational charge-induced disruption of hydrogen bonds when the net water flux is strongly affected by the vibrational frequency of the charge. In particular, the net flux is reaches a maximum when the vibrational frequency matches the inherent frequency of hydrogen bond inside the nanochannel. This electromanipulating transport phenomenon provides an important new mechanism of water transport confined in nanochannels.
