Lundelius’ rule

The solubility of the adsorbate is a controlling factor for adsorption with a given adsorbent. Its solubility in the solvent from which adsorption takes place has an inverse relationship with the extent of adsorption of an adsorbate (i.e., Lundelius rule). It may be postulated that strong forces exist between the adsorbate and solvent, and the breakup of such forces should be needed before adsorption can occur. The higher the solubility of the adsorbate in a solvent, the greater the forces and the smaller the extent of adsorption. 

From these results we conclude that the Lundelius rule, i.e., that the uptake of a solute is inversely proportional to its solubility in the solvent, does not apply to the uptake of the phenols by the PNIPA chains. 

Lundelius Rule. An expression for the inverse relation between solubility and the extent of adsorption of a species. 

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