Investigation of the adsorption behaviour of acetone at the surface of ice. A grand canonical Monte Carlo simulation study.
The adsorption isotherm of acetone at the surface of I(h) ice has been determined by a set of grand canonical Monte Carlo simulations at 200 K, by varying the chemical potential of acetone in the simulations. The obtained isotherm can be described by the Langmuir theory up to a certain relative pressure value (i.e., about 0.07); above which the isotherm increasingly deviates from the Langmuir form. This deviation mainly originates from the increasing importance of the lateral dipolar interactions. Further, above this pressure the adsorption sites are no longer equivalent: the adsorbed acetone molecules are aligned in three different ways. In one of these orientations the acetone molecule forms two, while in another one it forms one hydrogen bond with the surface waters, whereas in the third preferred orientation no hydrogen bonding occurs between the adsorbed molecule and the ice surface.
Hantal
György
G
Laboratory of Interfaces and Nanosize Systems, Institute of Chemistry, Eötvös Loránd University, Pázmány Péter stny. 1/a, H-1117, Budapest, Hungary. hantal@elte.hu
Jedlovszky
Pál
P
Hoang
Paul N M
PN
Picaud
Sylvain
S