Highly Conductive and Tough Hydrogels Based on Modulated Nanofluidic Channel Structures

In recent years, two-dimensional (2D) nanofluidic channels have attracted considerable attention due to their advantageous properties, which stem from their basis on 2D materials and their formation by an uncomplicated assembly process and controlled pretreatment. Here, we successfully constructed 2D nanofluidic channels based on 2D layered nanostructures (BT) in the acrylamide (PAAm)/chitosan (CS) system. Here, we employed acrylic acid to modulate the number of active sites on the BT lamellae, achieving a grafting rate of 90% on ACBT. Additionally, sodium citrate was used to modulate the dispersion of bentonite in the matrix, forming multiple 2D confining spacings as nanochannels for rapid cation transport. By engineering the structure of bentonite-based two-dimensional nanofluidic channels and optimizing the dispersion of bentonite, the number of effective fast channels within the hydrogel was notably increased, leading to a substantial enhancement in the electrical conductivity of the hydrogel material. The ionic conductivity of PACE hydrogel exhibited a 174% improvement compared to that of PCE hydrogel. Furthermore, this strategy yielded a high toughness (2.83 MJ/m3), high stress (286 kPa) and high strain (2551%) of the hydrogel. Providing some ideas for functional bentonite as a 2D nanofluidic channel, the prepared multifunctional ion conducting hydrogels show great application potential in the field of flexible wearable sensors.