Abstract
The aim of this study was to determine the adsorption and desorption isotherms of Tunisian clay product at different temperatures with a water activity varying from 10.95 to 97% using the statistic gravimetric method, which is an important step to evaluate its hygroscopic character. It was found that when temperature increases, clay material becomes less hygroscopic due to physical and/or chemical changes in product. Ten mathematical models were used to fit experimental data of sorption isotherms. The fitting of the model to experimental data was evaluated with the correlation coefficient (R2) and the root mean square error (RMSE). The Oswin model was determined to be the best model for describing experimental data of adsorption and desorption in the investigated ranges of temperature and water activity. The net isosteric heat of sorption determined from sorption isotherms estimated from Oswin model and using Clausius-Clapeyron equation decreased continuously with increasing the equilibrium moisture content.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
