Kinetics of gelatin transitions with phase separation: T-jump and step-wise DSC study.
The isothermal gelation (or melting) of gelatin after fast cooling (or heating) steps is studied by using high sensitivity differential scanning micro-calorimetry, in order to determine the dependence of the kinetic and thermodynamic parameters upon changes in composition and in temperature. The calorimetric heat flow curves, obtained according to defined temperature profiles, have been fitted with exponential functions (simple exponentials or stretched exponentials for the step-wise and for T-jump experiments, respectively). The gelation process of gelatin alone for t<300 min shows that the characteristic time tau and the fractional exponent are beta very sensitive to the concentration of gelatin chains and to the microscopic phase segregation due to the presence of another polymeric component.
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Dipartimento di Biochimica, Biofisica e Chimica delle Macromolecole, Università di Trieste, I-34127 Trieste, Italy.
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D002152:Calorimetry, Differential Scanning / Q000379:methods; D002153:Calorimetry, Indirect / Q000379:methods; D005780:Gelatin / Q000737:chemistry*; D007700:Kinetics; D013696:Temperature
D005780:Gelatin