The Flory-Huggins-Free-Volume (FHFV)theory, describing the moisture sorption of carbohydrates, is extended towards a wider range of compounds. Earlier application of the FHFV theory has been to carbohydrate/water mixtures, as can be found in foods. Now, we have extended the theory towards polyols (or polyalcohols)which are investigated in as proxies for secondary organic aerosols, whose behaviour is important for understanding climate behaviour. The investigated polyols are characterized by the ratio of the number hydroxyl groups NOH and the number of carbon atoms NC, which is often lower than ratios found in carbohydrates in food materials. We have found that the value of the Flory-Huggins interaction parameter is a function of the solute molecular properties, namely its chain length NC and the ratio NOH/NC of the solute. The deviation of this ratio from [Formula presented] can be viewed as a measure for its hydrophilicity. For food science, the extension of the theory has also significant implications, as the interaction parameter of newly investigated ingredients (rich in hydroxyl groups)can be estimated by means of the molecular properties. One must think of insoluble food fibers like xylan-glucans or arabinoxylans, or modified biopolymers based on starch or cellulose.
- Sorption isotherm