作者：Peng Sun, Hua Zhang, Dan Xu, Zhenwu Wang, Liufang Wang, Guorong Gao, Gaffar Hossain, Jiangyu Wu*,
关键字：Hydrogel Bilayer, Actuator, Multi-responsive, hydrogels, triblock copolymer micelles
论文来源：期刊
具体来源：Journal of Materials Chemistry B
发表时间：2019年
Intelligent hydrogels responsive to external stimuli have been widely studied due to their great potentials for applications in artificial muscles, soft robotics, sensors and actuators. However, the weak mechanical properties, narrow response range, and slow response speed of many responsive hydrogels have hindered practical applications. In this paper, tough multi-responsive hydrogels were synthesized by using vinyl-functionalized triblock copolymer micelles as macro-crosslinkers and N-isopropyl acrylamide (NIPAM) and acrylamide (AAm) or 2-(dimethylamino)ethyl methacrylate (DMAEMA) and 2-acrylamido-2-methyl-1-propane-sulfonic acid (AMPS) as monomers. The P(NIPAM-co-AAm) hydrogels presented tensile strength of up to 1.6 MPa and compressive strength of up to 127 MPa and were tunable by changing their formulations. Moreover, the lower critical solution temperature (LCST) of the thermosensitive hydrogels was manipulated in a wide range by changing the molar ratio of NIPAM to AAm. Responsive hydrogel bilayers were fabricated through a two-step synthesis. A second layer of P(DMAEMA-co-AMPS) was synthesized on the first P(NIPAM-co-AAm) layer to obtain a bilayer hydrogel, which was responsive to temperature, pH and ionic strength changes to undergo fast and reversible shape transformation in a few minutes. This kind of strong and tough multi-responsive hydrogel device has broad prospects in soft actuators.