초록 |
A hydrogel is highly hydrated polymer networks which can be used as a sensor based on its different swelling behavior by external stimuli. We present a poly(2-hydroxyethyl methacrylate)(pHEMA)-based copolymer hydrogel having different pH-dependent swelling behavior. The pHEMA hydrogel has little pH dependency. However, when the pHEMA is copolymerized with acrylic acid, the swelling ratios of the resulting copolymer show positive dependence on environmental pH. When the pHEMA is copolymerized with (2-dimethylamino)ethyl methacrylate, the copolymer shows the opposite pH dependency. Thus, the pH-dependent swelling behavior of the pHEMA-based copolymer hydrogel can be controlled by choosing appropriate functional groups. We also investigated the effect of the initiator and crosslinker contents on the pH-dependent swelling ratio of the copolymer hydrogel. The information presented here would be helpful to realize sensors or actuators based on stimuli-responsive hydrogels. |