Constructing Uranyl-Specific Nanofluidic Channels for Unipolar Ionic Transport to Realize Ultrafast Uranium Extraction

Effect of Time Dependent Excitation Signals on Gating in Nanofluidic Channels

Volume 7A: Fluids Engineering Systems and Technologies ◽

10.1115/imece2015-53038 ◽

2015 ◽

Author(s):

C. Boone ◽

M. Fuest ◽

K. Wellmerling ◽

S. Prakash

Keyword(s):

Electric Field ◽

Ionic Transport ◽

Local Variation ◽

Time Dependent ◽

Local Perturbation ◽

Gate Electrode ◽

Nanofluidic Channels ◽

Field Effect Devices ◽

Dc Excitation ◽

Dependent Signal

Nanofluidic field effect devices feature a gate electrode embedded in the nanochannel wall. The gate electrode creates local variation in the electric field allowing active, tunable control of ionic transport. Tunable control over ionic transport through nanofluidic networks is essential for applications including artificial ion channels, ion pumps, ion separation, and biosensing. Using DC excitation at the gate, experiments have demonstrated multiple current states in the nanochannel, including the ability to switch off the measured current; however, experimental evaluation of transient signals at the gate electrode has not been explored. Modeling results have shown ion transport at the nanoscale has known time scales for diffusion, electromigration, and convection. This supports the evidence detailed here that use of a time-dependent signal to create local perturbation in the electric field can be used for systematic manipulation of ionic transport in nanochannels. In this report, sinusoidal waveforms of various frequencies were compared against DC excitation on the gate electrode. The ionic transport was quantified by measuring the current through the nanochannels as a function of applied axial and gate potentials. It was found that time varying signals have a higher degree of modulation than a VRMS matched DC signal.

Download Full-text

Thermal control of ionic transport and fluid flow in nanofluidic channels

Nanoscale ◽

10.1039/c5nr05409e ◽

2015 ◽

Vol 7 (44) ◽

pp. 18799-18804 ◽

Cited By ~ 6

Author(s):

Mojtaba Taghipoor ◽

Arnaud Bertsch ◽

Philippe Renaud

Keyword(s):

Fluid Flow ◽

Ionic Transport ◽

Thermal Control ◽

Nanofluidic Channels ◽

Fast Mechanism

A thermal gate is an effective and fast mechanism for modulating the ionic transport in nanofluidic channels.

Download Full-text

Schottky diodes as a possible supplementary method for ionic transport investigations in semiconducting ionic solids — application to n-CdF2

Journal de Physique ◽

10.1051/jphys:01983004404055300 ◽

1983 ◽

Vol 44 (4) ◽

pp. 553-558

Author(s):

R.J. Iwanowski ◽

A. Lemańska-Bajorek ◽

J.M. Langer

Keyword(s):

Schottky Diodes ◽

Ionic Transport ◽

Supplementary Method ◽

Ionic Solids

Download Full-text

Exploring the Influence of Substitution on the Structure and Transport Properties in the Sodium Superionic Conductor Na11+xSn2+x(Sb1−yPy)1−xS12

10.26434/chemrxiv.12278237.v1 ◽

2020 ◽

Author(s):

Marvin Kraft ◽

Lara Gronych ◽

Theodosios Famprikis ◽

Saneyuki Ohno ◽

Wolfgang Zeier

Keyword(s):

Electrochemical Impedance ◽

Structural Phase ◽

Ionic Transport ◽

Sodium Ion ◽

Ionic Conductors ◽

Temperature Dependent ◽

Activation Barriers ◽

Rietveld Refinements ◽

High Performing ◽

The Given

Sulfidic sodium ion conductors are currently investigated for the possible use in all-solid-state sodium ion batteries. The design of high performing electrolytes in terms of temperature-dependent ionic transport is based upon the fundamental understanding of structure – transport relationships within the given structural phase boundaries inherent to the investigated materials class. In this work, the Na+ superionic structural family of Na11Sn2PS12 is explored by using the systematic antimony substitution with phosphorous in Na11+xSn2+x(Sb1-yPy)1-xS12. A combination of Rietveld refinements against X-ray synchrotron diffraction data with electrochemical impedance spectroscopy is used to monitor the changes in the anionic framework, the Na+ substructure and the ionic transport. A new simplified descriptor for the average Na+ diffusion pathways, the average Na+ polyhedral volume is introduced, which is used to correlate the contraction of the overall lattice and the found activation barriers in the system. This study exemplifies how substitution affects diffusion pathways in ionic conductors and widens the knowledge about the related structural motifs and their influence on the ionic transport in this novel class of ionic conductors.

Download Full-text

Changing the Static and Dynamic Lattice Effects for the Improvement of the Ionic Transport Properties Within the Argyrodite Li6PS5-xSexI

10.26434/chemrxiv.9807770.v1 ◽

2019 ◽

Author(s):

Roman Schlem ◽

Michael Ghidiu ◽

Sean Culver ◽

Anna-Lena Hansen ◽

Wolfgang Zeier

Keyword(s):

Ionic Conductivity ◽

Activation Barrier ◽

Parent Compound ◽

Ionic Transport ◽

X Ray Diffraction ◽

X Ray ◽

Lattice Effects ◽

Solid State Batteries ◽

All Solid State Batteries ◽

Pulse Echo

The lithium argyrodites Li6PS5X (X = Cl, Br, I) have been gaining momentum as candidates for electrolytes in all-solid-state batteries. While these materials have been well-characterized structurally, the influences of the static and dynamic lattice properties are not fully understood. Recent improvements to the ionic conductivity of Li6PS5I (which as a parent compound is a poor ionic conductor) via elemental substitutions have shown that a multitude of influences affect the ionic transport in the lithium argyrodites, and that even poor conductors in this class have room left for improvement.Here we explore the influence of isoelectronic substitution of sulfur with selenium in Li6PS5-xSexI. Using a combination of X-ray diffraction, impedance spectroscopy, Raman spectroscopy, and pulse-echo speed of sound measurements,we explore the influence of the static and dynamic lattice on the ionic transport. The substitution of S2-with Se2- broadens the diffusion pathways and structural bottlenecks, as well as leading to a softer more polarizable lattice, all of which lower the activation barrier and lead to an increase in the ionic conductivity. This work sheds light on ways to systematically understand and improve the functional properties of this exciting material family.

Download Full-text

Rapid Crystallization and Kinetic Freezing of Site-Disorder in the Lithium Superionic Argyrodite Li6PS5Br

10.26434/chemrxiv.9794588 ◽

2019 ◽

Author(s):

Ajay Gautam ◽

Marcel Sadowski ◽

Nils Prinz ◽

Henrik Eickhoff ◽

Nicolo Minafra ◽

...

Keyword(s):

Elevated Temperatures ◽

Synthesis Method ◽

Reaction Times ◽

Ionic Conductivities ◽

Ionic Transport ◽

High Energy ◽

Superionic Conductors ◽

Rapid Crystallization ◽

Site Disorder ◽

Fast Cooling

Lithium argyrodite superionic conductors are currently being investigated as solid electrolytes for all-solid-state batteries. Recently, in the lithium argyrodite Li6PS5X (X = Cl, Br, I), a site-disorder between the anionsS2–and X–has been observed, which strongly affects the ionic transport and appears to be a function of the halide present. In this work, we show how such disorder in Li6PS5Br can be engineered viathe synthesis method. By comparing fast cooling (i.e. quenching) to more slowly cooled samples, we find that anion site-disorder is higher at elevated temperatures, and that fast cooling can be used to kinetically trap the desired disorder, leading to higher ionic conductivities as shown by impedance spectroscopy in combination with ab-initiomolecular dynamics. Furthermore, we observe that after milling, a crystalline lithium argyrodite can be obtained within one minute of heat treatment. This rapid crystallization highlights the reactive nature of mechanical milling and shows that long reaction times with high energy consumption are not needed in this class of materials. The fact that site-disorder induced viaquenching is beneficial for ionic transport provides an additional approach for the optimization and design of lithium superionic conductors.

Download Full-text