MXene/Silk Fibroin Strengthened PVA–Based Eutectogel with Excellent Self–Healing Ability and Environmental Adaptability: Design, Synthesis, and Sensing Application

Abstract

A superelastic self–healing eutectogel was designed and prepared using poly (vinyl alcohol) (PVA) as the bulk skeleton material, while silk fibroin (SF) and two–dimensional (2D) MXene (Ti3C2TX) as reinforcing fillers. In brief, the eutectogel possesses a high tensile strength of 7.63 MPa, and its elongation at break reached 1115.2%, higher than most reported polymers (<1000%). In addition, the eutectogel–assembled sensor has a high ionic conductivity of 0.61 S/m and a high strain sensitivity of 5.17 kPa−1. Moreover, eutectogel shows excellent self–healing ability and can achieve self–healing quickly within 10 min, while its tensile strength and elongation at break can be restored to 84.7% and 97.4% of the initial levels. Besides, a stable electrical signal can be transmitted after 200 cycles at 30% strain. Finally, the eutectogel can withstand various environmental conditions, such as atmospheric or even vacuum evaporation and low–temperature freezing, while maintaining good mechanical and sensing performances. The assembled flexible sensors based on the eutectogel demonstrate their significant application prospects in wearable devices, especially human physiological monitoring.