Properties of patchy colloidal particles close to a surface: a Monte Carlo and density functional study


Autoria(s): Gnan, Nicoletta; Heras, Daniel de las; Tavares, José Maria; Gama, Margarida M. Telo da; Sciortino, Francesco
Data(s)

10/09/2015

10/09/2015

28/08/2012

Resumo

We investigate the behavior of a patchy particle model close to a hard-wall via Monte Carlo simulation and density functional theory (DFT). Two DFT approaches, based on the homogeneous and inhomogeneous versions of Wertheim's first order perturbation theory for the association free energy are used. We evaluate, by simulation and theory, the equilibrium bulk phase diagram of the fluid and analyze the surface properties for two isochores, one of which is close to the liquid side of the gas-liquid coexistence curve. We find that the density profile near the wall crosses over from a typical high-temperature adsorption profile to a low-temperature desorption one, for the isochore close to coexistence. We relate this behavior to the properties of the bulk network liquid and find that the theoretical descriptions are reasonably accurate in this regime. At very low temperatures, however, an almost fully bonded network is formed, and the simulations reveal a second adsorption regime which is not captured by DFT. We trace this failure to the neglect of orientational correlations of the particles, which are found to exhibit surface induced orientational order in this regime.

Identificador

GNAN, N.; [et al] – Properties of patchy colloidal particles close to a surface: a Monte Carlo and density functional study. Journal of Chemical Physics. ISSN: 0021-9606. Vol. 137, nr. 8 (2012)

0021-9606

http://hdl.handle.net/10400.21/5157

10.1063/1.4746428

Idioma(s)

eng

Publicador

Amer Inst Physics

Relação

Spanish Ministry of Education - EX2009-0121

Comunidad de Madrid, Spain - MODELICO-CM/S2009ESP-1691

Foundation of the Faculty of Sciences of the University of Lisbon

FCT - PEst-OE/FIS/UI0618/2011

FCT - PTDC/FIS/098254/2008

FP7 IRSES Marie-Curie - PIRSES-GA-2010-269181

ERC-226207-PATCHYCOLLOIDS

084704

Direitos

closedAccess

Palavras-Chave #Directional Attractive Forces #Hard-Sphere Fluid #Associating Fluids #Critical-Behavior #Simulation #Coexistence #Model #Crystals #Liquids #Mixture
Tipo

article