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Surface activity coefficients of ideal mixtures adsorbed on two‐site heterogeneous surface model
Author(s) -
TiRen Gu
Publication year - 1987
Publication title -
acta chimica sinica english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 0256-7660
DOI - 10.1002/cjoc.19870050104
Subject(s) - chemistry , adsorption , surface (topology) , thermodynamics , activity coefficient , ideal (ethics) , geometry , law , mathematics , physics , aqueous solution , political science
The surface activity coefficients of ideal mixtures adsorbed on the heterogeneous surfaces have been calculated systematically by using the two‐site heterogeneous surface model. The calculated results show that the apparent surface activity coefficients are always smaller than 1, i.e. , negative‐deviation from Raoult's law, which were always found experimentally. On the other hand, the calculated surface activity coefficients curves are always nearly symmetric if the total surface coverage is close to 1. This situation is comparable with those of adsorption from solutions. Therefore, the asymmetric curves for the surface activity coefficients may not be due to the heterogeneous of the surface, but due to the nonideal molecular interactions between the unlike components of the adsorbed mixture.