Attapulgite-Reinforced Robust and Ionic Conductive Composite Hydrogels for Digital Light Processing 3D Printing

Ionic conductive hydrogels are widely used in many applications such as electrochemical energy storage, flexible electronic devices, and catalyst transistors due to their excellent ionic conductivity as well as chemical stability. However, the fragile mechanical properties and the lack of shaping methods severely limit their further applications. Herein, an ionic conductive composite hydrogel with reinforced mechanical properties is demonstrated that can be rapidly 3D printed using digital light processing technology. By using both γ-methacryloxypropyltrimethoxysilane moderately modified attapulgite rigid particle and polyvinyl alcohol (PVA) semicrystal dual-network reinforcement, the mechanically robust and highly conductive N,N,N-trimethylethanaminium-chloride-based hydrogels are obtained, demonstrating a 5 times higher tensile strength than the initial one due to the turning and orienting of the attapulgite as well as the robust PVA secondary network. Furthermore, encapsulation strategy is used to avoid the dehydration of hydrogel, and strain sensors that exceed the strain limit of the hydrogel are fabricated through structural design. This work provides a reference for attapulgite-reinforced hydrogel in biosensing.