Cosorption of Sulfur Dioxide and Water on Cork

摘要

The cosorption of gaseous sulfur dioxide (SO_2) and water vapor (H_2O) on raw cork powder by using calorimetry coupled with manometry at 298 K was studied. Sorption isotherms of single components confirm the previous results obtained by thermogravimetry: SO_2 is well chemisorbed on cork surface while H_2O is only physisorbed. Moreover, the interaction of SO_2 and H_2O with cork appears more like an absorption process than an adsorption process. Competitive sorption of SO_2 and H_2O first occurs in favor of SO_2 chemisorption. After all chemisorption sites are saturated by SO_2, the cosorption process becomes selective for H_2O. The amount of SO_2 sorbed on cork is rather low compared to H_2O. Results indicate that the sorption of SO_2 on cork cannot explain the decrease in SO_2 content observed during wine aging in bottle.