Ionic diode desalination: Combining cationic Nafion™ and anionic Sustainion™ rectifiers

Tuning and Coupling Irreversible Electroosmotic Water Flow in Ionic Diodes: Methylation of an Intrinsically Microporous Polyamine (PIM-EA-TB)

“…For ionic diodes to be useful in devices, it is necessary to couple them into pairs/circuits to employ both positive and negative polarization periods during processes driven by AC electricity. It was shown recently that the combination of an anionic diode with a cationic diode offers an approach to net salination/desalination processes . Similarly, here it is demonstrated that coupling two anionic diodes based on PIM-EA-TB with a differing degree of methylation results in a process of net zero flux of anions coupled to a net unidirectional flux of water.…”

“…It has recently been demonstrated that ionic diodes can be coupled into ionic circuits to perform AC (alternating current)-electricity-driven functions. When combining an anionic diode with a cationic diode, a net transport of salt (anions and cations) is achieved in ionic diode desalination processes . Similarly, it is possible to couple two anionic diodes with different electroosmotic drag coefficients to perform a water pumping function (with net zero ion flow) .…”

Switching ionic diode states with proton binding into intrinsically microporous polyamine films (PIM-EA-TB) immersed in ethanol

“…A 4-electrode configuration is employed and the semicircle represents the capacitance of the Teflon film (typically 0.6 nF; at high frequency conductivity due to the capacitor prevails; data summarised in Table 3) with a series resistance due to the electrolyte solution and contacts (R1). The parallel resistance R2 is associated with the microhole region conductivity and with the PIM-EA-TB film deposit (R2, dominated by the PIM-EA-TB and the microhole region in the Teflon [33]).…”

Scanning Ion Conductance Microscopy of Nafion-Modified Nanopores

“…As demonstrated in a series of elegant studies by Marken and coworkers, this intriguing system can be utilized to create nanofluidic diodes with "on" and "off" states. [26][27][28][29][30] Here, we demonstrate modulation of ion transport properties across a silicon nitride (SiN x ) nanopore by the addition of Nafion. First, a comparison of the current-voltage response before and after the addition of the Nafion film was performed.…”