Interactions between paper and adsorbed moleculesA preliminary study and some experimental results

We have studied the geometry and energy involved in the interactions between adsorbed molecules and paper substrate, over a wide range of partial pressures. A two-dimensional virial equation of state was employed to evaluate the extent of interactions by the compressibility factor (Z). Data of H-bonded molecules (water and butan-1-ol) and of more weakly interacting ones (n-decane and dioxane) were selected from the literature. At low surface coverage, the compressibility factor Z exceeds 1, showing a deviation from ideality due to interactions, and reaches a maximum at a value close to the BET monolayer.