TY - JOUR
T1 - Effect of adsorption on the surface structure of sodium alumino-silicate glasses
T2 - a molecular dynamics simulation
AU - Athanasopoulos, D. C.
AU - Garofalini, S. H.
N1 - Funding Information:
The authors gratefully acknowledges upport from the US Department of Energy, Office of Basic Energy Sciences,D E-FG05-88ER45368.
PY - 1992/6/15
Y1 - 1992/6/15
N2 - Classical molecular dynamics (MD) computer simulations were used to study adsorption of model metals onto sodium alumino-silicate glasses and the effect these adsorbates have on the surface structure of the glass substrates. Multibody potentials were used to describe the substrate-substrate interactions; Lennard-Jones potentials were used to describe the adsorbate-adsorbate and adsorbate-substrate interactions. Lennard-Jones parameters and adsorbate mass were chosen to model Pt as the adsorbate. The adsorbate atoms penetrated 5-6Å into the glass, with multilayer coverage eventually occurring during deposition. The substrate showed a slight compression of the surface due to the presence of the adsorbate film. There was also a pronounced shift to smaller bond angles in the distribution of siloxane bond angles at the bridging oxygen. This redistribution was predominantly caused by a compression of siloxane bonds in 5 and 6 membered rings, although there was a partial rearrangement of ring sizes. Finally, Na at the surface were displaced by the adsorbate atoms such that Na were observed in the adsorbate film and at the film/vacuum interface.
AB - Classical molecular dynamics (MD) computer simulations were used to study adsorption of model metals onto sodium alumino-silicate glasses and the effect these adsorbates have on the surface structure of the glass substrates. Multibody potentials were used to describe the substrate-substrate interactions; Lennard-Jones potentials were used to describe the adsorbate-adsorbate and adsorbate-substrate interactions. Lennard-Jones parameters and adsorbate mass were chosen to model Pt as the adsorbate. The adsorbate atoms penetrated 5-6Å into the glass, with multilayer coverage eventually occurring during deposition. The substrate showed a slight compression of the surface due to the presence of the adsorbate film. There was also a pronounced shift to smaller bond angles in the distribution of siloxane bond angles at the bridging oxygen. This redistribution was predominantly caused by a compression of siloxane bonds in 5 and 6 membered rings, although there was a partial rearrangement of ring sizes. Finally, Na at the surface were displaced by the adsorbate atoms such that Na were observed in the adsorbate film and at the film/vacuum interface.
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U2 - 10.1016/0039-6028(92)90281-A
DO - 10.1016/0039-6028(92)90281-A
M3 - Article
AN - SCOPUS:0026882730
VL - 273
SP - 129
EP - 138
JO - Surface Science
JF - Surface Science
SN - 0039-6028
IS - 1-2
ER -