A pH Sensitive, Tough Hydrogel

Most of conventionally made hydrogels are mechanically brittle. However, there are different ways to toughen a weak hydrogel. Here, a brittle hydrogel (a bottle-brush type network) was toughened by introducing a second network within it. The second network (polyacrylic acid) is able to form hydrogen bonding with side chains of first network. These hydrogen bonds are pH sensitive, hence the physical and mechanical properties of the interpenetrating networks become pH sensitive as well. Published: J Polym Sci B 2012, 50 (6), 423-430.