Large Amplitude Oscillatory Shear Studies on the Strain-stiffening Behavior of Gelatin Gels  

作　　者：Wei-xiang Sun Li-zhen Huang Yan-rui Yang Xin-xing Liu 童真 

机构地区：[1]Research Institute of Materials Science and State Key Laboratory of Luminescent Materials and Devices,South China University of Technology

出　　处：《Chinese Journal of Polymer Science》2015年第1期70-83,共14页高分子科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.21204023);the National Basic Research Program of China(973 Program,2012CB821504);the Open Fund of the State Key Laboratory of Pulp and Paper Engineering(201346)

摘　　要：Linear and nonlinear viscoelasticity of gelatin solutions was investigated by rheology. The dynamic mechanical properties during the sol-gel transition of gelatin followed the time-cure superposition. The fractal dimension df of the critical gel was estimated as 1.76, which indicated a loose network. A high sol fraction ws = 0.61 was evaluated from the plateau modulus by semi-empirical models. Strain-stiffening behavior was observed under large amplitude oscillatory shear（LAOS） for the gelatin gel. The strain and frequency dependence of the minimum strain modulus GM, energy dissipation Ed, and nonlinear viscoelastic parameter NE was illustrated in Pipkin diagrams and explained by the strain induced helix formation reported previously by others. The BST model described the strain-stiffening behavior of gelatin gel quite well, whereas the Gent and worm-like chain network models overestimated the strain-stiffening at large strains.Linear and nonlinear viscoelasticity of gelatin solutions was investigated by rheology. The dynamic mechanical properties during the sol-gel transition of gelatin followed the time-cure superposition. The fractal dimension df of the critical gel was estimated as 1.76, which indicated a loose network. A high sol fraction ws = 0.61 was evaluated from the plateau modulus by semi-empirical models. Strain-stiffening behavior was observed under large amplitude oscillatory shear（LAOS） for the gelatin gel. The strain and frequency dependence of the minimum strain modulus GM, energy dissipation Ed, and nonlinear viscoelastic parameter NE was illustrated in Pipkin diagrams and explained by the strain induced helix formation reported previously by others. The BST model described the strain-stiffening behavior of gelatin gel quite well, whereas the Gent and worm-like chain network models overestimated the strain-stiffening at large strains.

关 键 词：Gelatin Large amplitude oscillatory shear Strain-stiffening. 

分 类 号：O648.17[理学—物理化学]