Discrete Electrolytes Research

Liquid ionics beyond Poisson-Boltzmann

Research - Ionic liquids

Ionic liquids in nanoconfinement exhibit specific flow properties due to near-wall molecular rearrangements.

Ionic liquids are salts that exist in the liquid phase at room temperature. This means they don't require solvent to act as electrolytes: every molecule is a fluidised ion and we should (perhaps naïvely) expect enhanced screening effects. This naturally lends ionic liquids towards applications in energy harvest and storage, helped even more by the fact the electrochemical window is several times that of water. Ionic liquids exhibit other peculiar behaviours too. Their ions stack in a semi-crystalline structure on immersed substrates, and the amount of molecular interlocking of adjacent ionic layers can be exploited for, e.g., lubrication.

As well as these important applications, several fundamental questions must be addressed. For example, the ion behaviour is clearly discretised rather than a continuum, so in what framework must we work? A second example regards how nanopores charge/discharge, whilst a third relates to how much the near-wall structure is templated by the underlying substrate and how much it depends on the substrate charge (even to what extent it can be tuned).

Who: James, Monchai Jitvisate

Collaborators: Wouter den Otter, René van Roij, Bala Sundaram, Anthony Thornton

Sponsors: DPST, FOM, DST.

Literature:

M. Jitvisate & J. R. T. Seddon
"Local structure and flow properties of ionic liquids on charged and inert substrates"
J. Phys. Chem. C 120, 4860 (2016)

J. R. T. Seddon
"Conservative and dissipative interactions of ionic liquids in nanoconfinement"
J. Phys. Chem. C 118, 22197 (2014)