Attapulgite-Reinforced\nCellulose Hydrogels with High\nConductivity and Antifreezing Property for Flexible Sensors

Abstract

Ionic conductive cellulose hydrogels\nare some of the\nmost promising\ncandidates for flexible sensors. However, it is difficult to simultaneously\nprepare cellulose hydrogels with high mechanical strength, good ionic\nconductivity, and antifreeze performance. In this work, a natural\nclay (attapulgite)-reinforced cellulose hydrogel was fabricated. Through\na one-pot method, cellulose and attapulgite were dispersed in a concentrated\nZnCl₂ solution. The obtained hydrogel exhibited a dual\nnetwork of hydrogen bonds and Zn²⁺-induced ionic interactions.\nAttapulgite serves as an inorganic filler that can regulate the hydrogen-bonding\ndensity among cellulose molecules and provides abundant channels for\nfast ion transport. By optimizing the attapulgite loading, a mechanically\nstrong (compressive strength up to 1.10 MPa), tough (fracture energy\nup to 0.36 MJ m^–3), highly ionic conductive (4.15\nS m^–1), and freezing-tolerant hydrogel was prepared.\nThese hydrogels can be used for sensitive and stable human motion\nsensing, demonstrating their great potential for healthcare applications.