Temperature and Voltage Dual-Responsive Ion Transport in Bilayer-Intercalated Layered Membranes with 2D Nanofluidic Channels

The controllable ion transport in synthetic membranes with nanofluidic channels by external stimuli has been attracting significant attention for nanofluidic diodes, biosensing, nanoreactors, and energy conversion. Here, we report a synthetic bilayer-intercalated layered membrane with two-dimensional (2D) nanofluidic channels, in which the ion transport can be controlled by external stimuli of temperature and voltage. The synthesis of the layered membranes includes the exchange of native cations in montmorillonite with the quaternary ammonium ions in a cationic surfactant and a subsequent vacuum filtration. The bilayer-intercalated interlayer spaces in the layered membranes act as 2D nanofluidic channels for ion transport. The phase state of the bilayers and the surface polarity of functionalized montmorillonite lamellae can be controlled by external temperature and voltage, respectively, which imbue the layered membranes with dual-responsive ion transport properties. Our dual-responsive layered membranes with 2D nanofluidic channels provide a new platform for creating smart synthetic membranes to control the ion transport.