Viscoelastic behaviour at the thermal sol-gel transition of gelatin

摘要: Rheological studies of gelatin solutions in the concentration range 4–14% were performed through sol-gel transition as a function concentration, pH and ionic strength. At gel point, power-law frequency dependence viscoelastic functions G′(ω), G″(ω) η∗(ω) was observed. The exponents n obtained from these dynamic measurements confirmed by creep experiments are agreement with previous study lower range, 1–5%. Under all conditions, values fall between 0.64 0.72, consistent theoretical treatments Martin et al. Muthukumar critical strength, S, increases approximately S ∝ C1.33 4–14%. Within experimental error, is an empirical relation suggested recent literature, = G1 − neηno, where Ge ηo are, respectively, equilibrium modulus fully developed shear viscosity initial sol. implications observations respect to structure discussed.