@article {184,
	title = {Ion-specific adsorption and electroosmosis in charged amorphous porous silica},
	journal = {Phys. Chem. Chem. Phys.},
	volume = {17},
	year = {2015},
	month = {Oct-14-2015},
	pages = {24683 - 24695},
	abstract = {<p>Monovalent and divalent aqueous electrolytes confined in negatively charged porous silica are studied by means of molecular simulations including free energy calculations. Owing to the strong cation adsorption at the surface, surface charge overcompensation (overscreening) occurs which leads to an effective positive surface next to the Stern layer, followed by a negatively charged diffuse layer. A simple Poisson-Boltzmann model in which the single-ion potential of mean force is introduced is shown to capture the most prominent features of ion density profiles near an amorphous silica surface. Nevertheless, due to its mean-field nature, which fails to account for correlations, this simple model does not predict overscreening corresponding to charge inversion at the surface. Such an overscreening drastically affects the transport of confined electrolytes as it leads to flow reversal when subjected to an electric field. A simple continuum theory is shown to capture how the electro-osmotic flow is affected by overscreening and by the apparent enhanced viscosity of the confined electrolytes. Comparison with available experimental data is discussed, as well as the implications of these phenomena for \&zeta;-potential measurements.</p>
},
	issn = {1463-9076},
	doi = {10.1039/C5CP03818A},
	author = {Hartkamp, Remco and Bertrand Siboulet and Jean-Francois Dufreche and Benoit A. Coasne}
}
@article {83,
	title = {Ionic liquid confined in silica nanopores: molecular dynamics in the isobaric-isothermal ensemble},
	journal = {Molecular Physics},
	volume = {112},
	year = {2014},
	month = {Avr-03-2014},
	pages = {1350-1361},
	type = {Article},
	abstract = {<p>Molecular dynamics simulations in the isobaric-isothermal ensemble are used to investigate the structure and dynamics of an ionic liquid confined at ambient temperature and pressure in hydroxylated amorphous silica nanopores. The use of the isobaric-isothermal ensemble allows estimating the effect of confinement and surface chemistry on the density of the confined ionic liquid. The structure of the confined ionic liquid is investigated using density profiles and structural order parameters while its dynamics is assessed by determining the mobility and ionic conductivity of the confined phase. Despite the important screening of the electrostatic interactions (owing to the small Debye length in ionic liquids), the local structure of the confined ionic liquid is found to be mostly driven by electrostatic interactions. We show that both the structure and dynamics of the confined ionic liquid can be described as the sum of a surface contribution arising from the ions in contact with the surface and a bulk-like contribution arising from the ions located in the pore centre; as a result, most properties of the confined ionic liquid are a simple function of the surface-to-volume ratio of the host porous material. In contrast, the ionic conductivity of the confined ionic liquid, which is a collective dynamical property, is found to be similar to the bulk. This study sheds light on the complex behaviour of hybrid materials made up of ionic liquid confined in inorganic porous materials.</p>
},
	keywords = {amorphous silica, ionic liquids, molecular dynamics, surface},
	issn = {0026-8976},
	doi = {10.1080/00268976.2014.902138},
	author = {Guido Ori and Fran{\c c}ois Villemot and Lydie Viau and Andre Vioux and Benoit A. Coasne}
}
