Abstract: Previous work has shown that dimethyldioctadecyl ammonium montmorillonite is a very effective adsorbent in the gas phase for the separation of aromatic compounds from the paraffins, and for the separation of the disubstituted isomers of benzene. The present paper describes an investigation into this phenomenon.
For this purpose a method of calculating entropies of adsorption from gas chromatographic data was derived, and results are given for relevant organic vapours adsorbed on the quaternary ammonium derivative, and on octadecyl ammonium montmorillonite. These results throw considerable light on the basis of the selectivity shown by the quaternary ammonium derivative, and a possible explanation of the mechanism is given.
The effect of the method of preparation on the gas phase activity of this adsorbent is very large, and experimental work on the correlation of this with the structure of the derivative is described.