Water sorption phenomenology

It should be noted that, even if several authors 7> 37) have collected a series of equilibrium sorption data for commonly used epoxy matrices exposed to humid environments that can be adequately described by Eq. (1) containing a concentration independent parameter, but often two terms of the phenomenological power series of water activity are used. 

Since carbon molecular sieves are amorphous materials, the dimensions of their pore structures must be measured phenomenologically by the adsorption of small probe molecules with different critical dimensions. There is insufficient long range order to utilize standard x-Ray diffraction methods for characterization. The earliest reports of molecular sieving carbons dealt primarily with coals and charcoals. Sorption of helium, water, methanol, n-hexane, and benzene was measured and related to the porosity of the carbon. Pore-sizes were estimated to be two to six angstroms (3-6). In a classic paper P.H. Emmett described methods for tailoring the adsorptive properties and pore size distributions of carbon Whetlerites. 

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