ABSTRACT
Abstract The interaction of the water molecules from the environment with foods and other materials can be evaluated using sorption isotherms. Films and biodegradable films are susceptible to changes in their functional characteristics due to adsorbed water. The amount of moisture that biodegradable films can adsorb depends on the temperature, relative humidity of the storage area and chemical composition. Several mathematical models can be used to describe the behavior of sorption isotherms in biodegradable films and some of them have been modified to include the temperature parameter into the equation. In this research, the original and modified BET, GAB, Halsey, Henderson and Oswin models were assessed to determine their suitability describing the behavior of moisture adsorption isotherms of chitosan films at 15, 20, 25 and 30 °C. The modified models of GAB, Oswin and Halsey gave the best fit to the experimental sorption data of the chitosan films, with R2 values higher than 0.97 demonstrating that those models describe better the sorption isotherms at the temperatures studied.
ABSTRACT
The aim of this study was to prepare chitosan film and to study its hemostatic properties. Chitosan film was prepared by casting the mixed solution of dialysed chitosan and gelatin after crosslinking with glutaraldehyde in a freeze dryer. Bleeding times were measured for bilateral back incisions (5 incisions on each side) in 4 New Zealand white rabbits. Using a randomized, blinded experimental design, one incision in each animal was treated with chitosan film, the other was treated with gauze. After bleeding stopped ,hemoglobin amount in films or gauzes was measured to determine the hemostatic effect. The results showed that the chitosan film adhered well to incisions. Bleeding times and hemoglobin amounts in chitosan film group were superior to those in gauze group( P