Multilayer adsorption

Adsorption in which material can form more than one layer above a surface. The number of adsorbed particles per underlying site can exceed one and differs from the fraction of sites having any adsorbate.

An ideal column model with the same adsorption-to-desorption ratio at every height. With $x=Kp$, the stationary height distribution is $P(j)=(1-x)x^j$ for $0\le x<1$, and its mean is $x/(1-x)$. Unlimited height makes the mean diverge as $x\to 1^{-}$; at $x\ge 1$ no normalized equilibrium height distribution exists.