TY - JOUR T1 - Nanofluidic Osmotic Diodes: Theory and Molecular Dynamics Simulations JF - Physical Review Letters Y1 - 2013 A1 - Picallo, Clara B A1 - Simon Gravelle A1 - Joly, Laurent A1 - Charlaix, Elisabeth A1 - Lydéric Bocquet AB -

Osmosis describes the flow of water across semipermeable membranes powered by the chemical free energy extracted from salinity gradients. While osmosis can be expressed in simple terms via the van ’t Hoff ideal gas formula for the osmotic pressure, it is a complex phenomenon taking its roots in the subtle interactions occurring at the scale of the membrane nanopores. Here we use new opportunities offered by nanofluidic systems to create an osmotic diode exhibiting asymmetric water flow under reversal of osmotic driving. We show that a surface charge asymmetry built on a nanochannel surface leads to nonlinear couplings between water flow and the ion dynamics, which are capable of water flow rectification. This phenomenon opens new opportunities for water purification and complex flow control in nanochannels.

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VL - 111 ER -