Bulk ionic screening lengths from extremely large-scale molecular dynamics simulations

Abstract

Large-scale molecular simulations reveal two screening lengths satisfying distinct scaling relations but with unprecedented accuracy no underscreening is detected for concentrated ionic bulk systems.

From Water Solutions to Ionic Liquids with Solid State Nanopores as a Perspective to Study Transport and Translocation Phenomena

“…[58] Consequently, the system is not dominated by the thermal motion (the entropy), but rather gains some sort of ordering. Apart from concentrated solutions of 1:1 electrolytes, similar behaviors are observed and theoretically reproduced for ionic liquids systems, [56,150] or biphasic aqueous systems. [151] Theoretical predictions are up to now valid quantitatively for Debye dilute concentration regime, and beyond that on a qualitative level.…”

Phase Transitions and Electrochemical Properties of Ionic Liquids and Ionic Liquid—Solvent Mixtures

“…The scaling behavior was observed for a number of simple salts (NaCl, LiCl, Kl, CsCl) in water, and for 1-butyl-1-methylpyrrolidinium bis[(trifluoromethyl)sulfonyl]imide ([C4C1Pyrr][NTf2]) in a number of solvents (propylene carbonate, dimethyl sulfoxide, acetonitrile, anhydrous benzonitrile), as well as for pure ILs [C2mim][NTf2] and [C3mim][NTf2] (in the latter case, the temperature dependence was verified). A scaling law for the screening length has been confirmed in theories based on different assumptions [ 136 , 137 , 138 , 139 , 140 , 141 ] and in all-atom molecular dynamics simulations [ 142 , 143 ]. The scaling exponents, however, appeared to be significantly lower than the experimentally measured one.…”

Design of concentrated colloidal dispersions of iron oxide nanoparticles in ionic liquids: Structure and thermal stability from 25 to 200 °C

“…A steric contribution, here due to the SBMIM ± layer may also occur. However, the relatively short range of the interaction balance (characteristic length Ù 1 nm) observed by SANS and SAXS and its relative independence with temperature, is not compatible with the long-range repulsion, which has been frequently evidenced in ionic liquids and concentrated salt solutions by SFA force measurements [29,30]. This long-range force of purely electrostatic origin typically extends for EMIM TFSI between symmetric mica surfaces, on a characteristic spacial length  *1 of 6.6 nm at 22 ˝C and decreases to 4.4 nm at 50 ˝C [31], much larger than the value obtained here.…”

“…These ions (even at low concentrations) have an influence as they can locate at the interface. Besides, a long-range repulsion has been evidenced in ionic liquids and concentrated salt solutions [29,30] by SFA force measurements between charged plates in various ILs. This repulsion, the mechanism of which is still under debate, extends over distances larger than the few layers formed close to the surface.…”