PROJECT TITLE :

Dissipative properties and chain evolution of highly strained nanocomposite hydrogel

ABSTRACT:

The dissipative property is crucial to the toughness and recovery of hydrogels. In our investigation, systematic uniaxial tension tests were conducted to judge the dissipative properties of poly (N-isopropylacrylamide) nanocomposite hydrogels. Two dissipative mechanisms are presented for each little and massive stretches. Before yielding, most dissipation results from the orientation of clay platelets along the tensile direction; when yielding, polymer chains peel aloof from clay platelets to induce hysteresis. For the primary time, a quadratic power law between the hysteresis work and the most stretch is obtained. The hysteresis work is irrelevant to the detailed loading history. When the hydrogel is unloaded to a crucial displacement, polymer chains will re-adsorb to the surfaces of clay platelets. The quantity of re-ruptured physical bonds is proportional to the merchandise of re-adsorption ratio which of initially ruptured bonds. These results may be useful for the toughening design of hydrogels.