Rheology of Hydrogels

Abstract

Recent development of rheology of hydrogels is reviewed. Rheological studies of clotting process of a fibrinogen-thrombin system and of a rennet-milk system are described. The temperature dependence of elastic modulus of thermo-reversible gels is explained by a simple model consisting of junction zones which are connected by long flexible chains. The entropic and energetic contributions to the elastic modulusare separated for agarose gels with different molecular weights. The concentration dependence of elastic modulus of gels is explained by Clark and Ross-Murphy's cascade treatment, and by Oakenfull's model. Percolation theory was used for analyzing the cascade treatment, and by Oakenfull's mcdel. Percolationwas theory used for analyzing the temperature and concentration dependence of elastic modulus by Tokita for agarose vels is briefly described.