화학공학소재연구정보센터
Macromolecular Rapid Communications, Vol.33, No.8, 698-702, 2012
Gelation on Heating of Supercooled Gelatin Solutions
Diluted (1.01.5 wt%) aqueous gelatin solutions have been cooled to 10 degrees C at a cooling rate 20 degrees C min-1 without freezing and detectable gelation. When heated at a constant heating rate (0.5 2 degrees C min-1), the obtained supercooled solutions demonstrate an atypical process of gelation that has been characterized by regular and stochastically modulated differential scanning calorimetry (DSC) as well as by isoconversional kinetic analysis. The process is detectable as an exothermic peak in the total heat flow of regular DSC and in the nonreversing heat flow of stochastically modulated DSC. Isoconversional kinetic analysis applied to DSC data reveals that the effective activation energy of the process increases from approximately 75 to 200 kJ mol-1 as a supercooled solution transforms to gel on continuous h eating.