Interfacial layering of a room-temperature ionic liquid thin film on mica: a computational investigation
Articolo
Data di Pubblicazione:
2012
Citazione:
Interfacial layering of a room-temperature ionic liquid thin film on mica: a computational investigation / D. Dragoni, N. Manini, P. Ballone. - In: CHEMPHYSCHEM. - ISSN 1439-4235. - 13:7(2012), pp. 1772-1780.
Abstract:
The structure of a thin (4 nm) [bmim][Tf2N] film on mica has been studied b
y molecular dynamics simulations
using an empirical force field.
Interfacial layering at T=300 K and at T=350 K is investigated
by determining the number- and charge-density profiles of [bmim][Tf2N] as a function of distance from mica,
and by computing the normal force Fz opposing the penetration of the ionic liquid film by a spherical nanometric tip interacting with [bmim][Tf2N] atoms by a short-range potential.
The results show that layering is important but localised within ~1 nm from the interface.
The addition of a surface charge on mica, globally neutralised by an
opposite charge on the [bmim][Tf2N] side,
gives rise to low-amplitude charge oscillations extending through the entire film.
However, outside a narrow interfacial region, the resistance of the
[bmim][Tf2N] film to penetration by the mesoscopic tip is only marginally affected by the charge at the interface.
The results obtained here for [bmim][Tf2N]/mica are similar to those obtained using the same method for the [bmim][Tf2N]/silica interface, and agree well with experimental force-distance profiles measured on the latter interface at ambient conditions.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
conformation analysis; ionic liquids; molecular dynamics; self-assembly; surface analysis
Elenco autori:
D. Dragoni, N. Manini, P. Ballone
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