Alireza Davaripour - Caspian Faculty of Engineering, College of Engineering, University of Tehran, Rezvanshahr, Iran.
Amir Eslahi Kalurazi - Caspian Faculty of Engineering, College of Engineering, University of Tehran, Rezvanshahr, Iran.
Mohsen Shahrousvand - Caspian Faculty of Engineering, College of Engineering, University of Tehran, Rezvanshahr, Iran.
Jamshid Mohammadi-Rovshandeh - Caspian Faculty of Engineering, College of Engineering, University of Tehran, Rezvanshahr, Iran.
Seyed Mohammad Davachi - Department of Biology and Chemistry, Texas A&M International University, Laredo, TX ۱۴۰۸۱ , USA.

Hydrogels are swollen and porous materials that contain water with a polymer substrate or othercomponents such as protein, peptide, colloid, surfactant, or lipid, which are used in the food andpharmaceutical industries. To understand the mechanical properties, the effects of nanoparticles,changes in temperature and concentration, the presence of other components, and the pattern of drugrelease, rheology is a fundamental tool. The gelation point of these gels can determine whenpolymeric materials are injected or applied at a specific point in the body. when they become a geland provide the desired performance. In this article, the critical point of the gel in polymer gels isinvestigated. Based on the results, the critical point of the gel is dependent on the applied frequencyand defects of the physical interlocking memory network. Also, the gelation time of hydrogels hasbeen investigated using different rheological tests.

Hydrogels, Polymers, Rheology, Gelation time.