Mechanically Robust, Electrically Conductive and Stimuli-Responsive Binary Network Hydrogels Enabled by Superelastic Graphene Aerogels

摘要

Stimuli-responsive hydrogels with decent mechanical and electrical properties hold great promise for a range of applications such as electrochemical sensors, electro-stimulated biomedical devices and actuators. However, traditional stimuli-responsive hydrogels are generally mechanically weak and electrically non-conductive, limiting their adoption in practical applications. Both the mechanical strength and electrical conductivity of hydrogels can be greatly enhanced by the incorporation of a considerable amount of conducting nanofillers, however, the addition of high content of nanofillers often suppresses the hydrogel's unique stimuli-responsive behavior.Synthesis of hydrogels that can combine good stimuli-responsiveness and desirable mechanical/electrical properties has proved to be very challenging. Here, we present a new strategy to tackle this long-term dilemma by using an ultralight, mechanically efficient graphene-based cellular aerogel as a scaffold to reinforce polymer hydrogels. This approach allows us to use a very small amount of graphene (as low as 0.045 vol.%) to significantly enhance the mechanical strength and electrical conductivity of hydrogels without compromising their stimuli-responsiveness.