Self-strengthening stimuli-responsive nanocomposite hydrogels

Abstract

-isopropylacrylamide) (PNIPAM) and nanoclay (NC) by using external stimuli such as heat and ionic strength. The internal structures of the NC-PNIPAM hydrogel are rearranged through the swelling-deswelling cycles or immersing in a salt solution, thus its mechanical properties are significantly improved. The effects of concentration of NC in hydrogels, number of swelling-deswelling cycles, and presence of salt in the surrounding environment on the mechanical properties of hydrogels are characterized by nanoindentation and tensile tests. The self-strengthening mechanical performance of the hydrogels is demonstrated by the loading ability. This work may offer promise for applications such as artificial muscles and soft robotics.