ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 21, Number 5
JKCSEZ 21(5)
October 20, 1977 

In this paper we propose a new theory of multilayer physical adsorption based on the view that a second or higher layer molecule will be adsorbed above the center of a square or triangular array of molecules, rather than on top of molecules themselves, in the next lower layer and the corresponding adsorption isotherm is derived. The derived isotherm contains three adjustable parameters; vm (monolayer capacity), q/q1 (ratio of the molecular partition function for the second or higher layer vs. that for the first layer) and n (a parameter characterizing the piling pattern of adsorbed molecules). When applied to adsorption of argon on "Carbolac" carbon and nitrogen on Linde silica, excellent agreements between observed and calculated values are obtained up to p/p0 = 0.8. In both cases n = 3 gives the best fit and this probably indicates that adsorbed molecules are piled up in a closest packing pattern.