Ionic liquid-assisted stabilization of MXene in polysaccharide-chitosan hydrogels with mechanical enhancement for...

In this study, a novel composite functional hydrogel was developed, integrating outstanding mechanical properties, remarkable catalytic activity, and highly sensitive sensing performance. Here, the dispersion behavior of Ti₃C₂T_x(MXene) via ionic liquids was examined, focusing on the interplay between surface functional groups of MXene and IL. The study aims to elucidate the mechanisms governing dispersion stability. Subsequently, a novel Polyacrylamide(PAM)/Polyacrylic acid(PAA)/Chitosan/ionic liquid(IL)-MXene hydrogel was designed. PAM/PAA offers a 3D framework, multiple bonds such as hydrogen bonds and electrostatic interactions are formed with PAM/PAA and chitosan by IL-MXene, and the mechanical strength of the hydrogel is further enhanced. Meanwhile, the hydrogel is endowed with good electrical conductivity and sensing capabilities by MXene, which serves as a conductive filler. A strain of 2980 %, a tensile strength of 1050 kPa are displayed by the hydrogel. Simultaneously, it exhibits high gauge factor (GF) and a rapid response time. Under an eco-conscious waste management framework, the functional regeneration of waste hydrogels into high-performance adsorbents represents a significant advancement in sustainable environmental remediation. For instance, the discarded pAAm/PAA/Chitosan/IL-MXene hydrogel system serves as an effective template for the in situ synthesis of gold nanoparticles (Au NPs), demonstrating exceptional catalytic activity in the reduction of 4-nitrophenol (4-NP). Beyond its catalytic efficiency, this composite hydrogel exhibits outstanding mechanical robustness and multifunctionality. In particular, the chitosan within the hydrogel matrix plays a significant role in enhancing antibacterial properties. Moreover, even after undergoing several catalytic cycles, it still maintains >90 % of its original state, indicating excellent cyclic stability and recyclability. Due to these outstanding characteristics, multifunctional hydrogel holds great promise for applications in the fields of flexible sensors and catalysis.