Interface interaction-mediated design of tough and conductive MXene-composited polymer hydrogel with high stretchability and low hysteresis for high-performance multiple sensing

Abstract

Conductive hydrogels based on two-dimensional (2D) nanomaterials, MXene, have emerged as promising materials for flexible wearable sensors. In these applications, the integration of high toughness, ultrastretchability, low hysteresis, self-adhesiveness, and multiple sensory functions into one gel is essential. However, serious issues, such as easy restacking and inevitable oxidation of MXene nanosheets in aqueous media and weak interfacial bindings between MXene and the gel network, make it almost impossible to achieve the multiple performances mentioned above. Here we present a conductive MXene-composited polymer (MCP) hydrogel by incorporating gelatin-modified MXene into polyacrylamide (PAAm) hydrogel for the fabrication of multifunctional sensors. The presence of gelatin not only greatly improves the stability of the MXene nanosheets by forming a protective sheath, but also largely enhances the interfacial interactions between the MXene and the hydrogel network as molecular glues. Thus, the MCP hydrogel exhibits a high strength (430 kPa), remarkable stretchability (1100%), low hysteresis (<10% at 500% cyclic tensile), and excellent repeatable adhesion. The resultant MCP hydrogel-based versatile sensors display a high strain sensitivity with a broad working range (gauge factor (GF) = 8.83, up to 1000%), realizing the detection of various human motions. Moreover, the prepared sensors possess superior thermosensitive capacities (1.110/°C) for the measurement of body temperature. This strategy opens horizons to designing high-performance MXene-based hydrogels for advanced sensing platforms.

A highly tough, fatigue-resistant, low hysteresis hybrid hydrogel with a hierarchical cross-linked structure for wearable strain sensors

“…Compared to the recently reported stretchable hydrogels, the PAM–HA–Zn1.0 hydrogel possessed higher breaking elongation and toughness (Table S2†). 9,33–41…”

“…The conductivity of the hydrogels was measured at ambient temperature with an electrochemical workstation (CHI760E, CH Instruments, China) by the alternating current impedance method. 9 The real-time electric resistance change of the hybrid hydrogel caused by the external force was recorded by using the same electrochemical workstation. The relative resistance change (RRC) and the gauge factor (GF) of the hydrogel were calculated individually as:RRC = ( R − R 0 )/ R 0 GF = ( R − R 0 )/( ε × R 0 )where R 0 is the initial resistance at the strain value of 0, and R is the dynamic resistance at a strain value of ε during measurement.…”

“…Natural polymers, including cellulose, 8 gelatin, 9 chitin, 10 chitosan, 11 and hyaluronic acid (HA), 12 are widely used to construct hydrogel materials because of their good renewability and ideal biodegradability properties. Among them, HA is one such glycosaminoglycan with abundant active functional groups such as hydroxyl and carboxyl groups, which makes it highly favorable for intermolecular chains entanglement and the formation of a large number of intermolecular hydrogen bonds.…”

An All-Solid-State Flexible Supercapacitor Based on MXene/MSA Ionogel and Polyaniline Electrode with Wide Temperature Range, High Stability, and High Energy Density

“…Tifeng Jiao et al found that by adding gelatin-modified MXene to the Polyacrylamide (PAAm) hydrogel, the tensile strength increased significantly (1100%) and the tensile strength increased significantly (430 kPa). [ 12 ]. Up to now, there have been few studies of all-solid supercapacitors based on ionic liquid gel electrolytes.…”

Self-Assembled Nanocomposites and Nanostructures for Environmental and Energic Applications

“…With the rapid development of nanotechnology, nanocomposites and nanostructures have attracted significant attention due to their unique physical and chemical properties and variable functionalities [ 1 , 2 , 3 ]. Both the various compositions and the construction process of nanostructured composites influence their performances, with application areas ranging from new chemical reactions, organic semiconductors, photovoltaic technology, and photocatalysts to biosensors and energy materials [ 4 , 5 , 6 ].…”