Characterization of sepiolite by inverse gas chromatography at infinite and finite surface coverage

The adsorption properties of sepiolite from Andrici, Serbia, were studied by inverse gas chromatography at zero and finite surface coverage between 483 and 513 K. The thermodynamic parameters (free energy, enthalpy, entropy) of adsorption, as well as the dispersive and specific components of the free energy of adsorption and the acid/base of the solid were calculated from the IGC data at zero coverage. The KD/KA ratio indicated basis character. The adsorption isotherms were used to estimate the specific surface area, isosteric heat of adsorption and the adsorption energy distribution for the adsorption of organic molecules.