Transparent and Recyclable Ionogels Enabled by Dynamic Networks Containing Poly(Thioctic Acid) for Flexible Sensors.

Abstract

Ionogels filled with non-volatile ionic liquids effectively mitigate issues such as solvent volatilization, making them suitable for flexible sensors. However, it remains challenging to fabricate recyclable ionogels with outstanding mechanical properties, high transparency, and recyclable capabilities. In this study, a transparent ionogel with dynamic networks is prepared by in situ polymerization of thioctic acid (TA) with polyvinyl pyrrolidone (PVP) in a halometallate ionic liquid. Due to the abundant dynamic crosslinks formed between the halometallate ionic liquid and PTA along with the rigidity of PVP, the ionogels exhibited excellent mechanical strength (≈6.14 MPa), satisfying stretchability (≈1000%), and high toughness (≈20.08 MJ m^-3). Meanwhile, the ionogel displayed high transparency, UV shielding capability, recyclability, and reprocessability. Enabled by the electrochemical properties, the ionogel can be used for flexible sensors, demonstrating good sensitivity and stability for repeatable use. This work provides a straightforward approach for synthesizing high-performance ionogels for flexible sensing applications.