Ultrafast water permeation through nanochannels with a densely fluorous interior surface

Ultrafast water permeation in aquaporins is promoted by their hydrophobic
interior surface. Polytetrafluoroethylene has a dense fluorine surface,
leading to its strong water repellence. We report a series of fluorous
oligoamide nanorings with interior diameters ranging from 0.9 to 1.9
nanometers. These nanorings undergo supramolecular polymerization in
phospholipid bilayer membranes to form fluorous nanochannels, the interior
walls of which are densely covered with fluorine atoms. The nanochannel
with the smallest diameter exhibits a water permeation flux that is two
orders of magnitude greater than those of aquaporins and carbon nanotubes.
The proposed nanochannel exhibits negligible chloride ion (Cl – )
permeability caused by a powerful electrostatic barrier provided by the
electrostatically negative fluorous interior surface. Thus, this
nanochannel is expected to show nearly perfect salt reflectance for
desalination.