  Adsorption properties of chain fluids are of interest from both fundamental
and industrial points of view. Density Functional Theory (DFT) based models are
among the most appropriate techniques allowing to describe surface phenomena.
At the same time Statistical Associating Fluid Theory (SAFT) successfully
describes bulk PVT properties of chain-fluids. In this publication we have
developed novel version of SAFT-DFT approach entitled RS-SAFT which is capable
to describe adsorption of short hydrocarbons on geometrically rough surface.
Major advantage of our theory is application to adsorption on natural roughs
surfaces with normal and lateral heterogeneity. For this reason we have
proposed workflow where surface of real solid sample is analyzed using
theoretical approach developed in our previous work [1] and experimentally by
means of low temperature adsorption isotherm measurements for simple fluids. As
result RS-SAFT can predict adsorption properties of chain fluids taking into
account geometry of the surface sample under the consideration. In order to
test our workflow we have investigated hexane adsorption on carbon black with
initially unknown geometry. Theoretical predictions for hexane adsorption at
303K and 293K fit corresponding experimental data well.
