Strong, tough, ionic conductive, and freezing-tolerant all-natural hydrogel enabled by cellulose-bentonite coordination interactions

Ionic conductive hydrogels from naturally abundant cellulose are ideal for flexible electronics due to their commercial viability and environmental sustainability. However, achieving both high mechanical strength and ionic conductivity in cellulosic hydrogels is challenging because charge carriers disrupt cellulose's hydrogen-bonding network. This study introduces a supramolecular engineering strategy to enhance the mechanical and ionic conductivity of cellulosic hydrogels by incorporating bentonite (BT) through strong cellulose-BT coordination interactions and the ion regulation of the nanoconfined cellulose-BT intercalated nanostructure. A strong (compressive strength up to 3.2 MPa), tough (fracture energy up to 0.45 MJ m⁻³), highly ionic conductive, and freezing-tolerant (high ionic conductivities of 89.9 and 25.8 mS cm⁻¹ at 25 and −20 °C, respectively) all-natural cellulose-BT hydrogel was successfully created. This research opens new avenues for designing cellulosic hydrogels.

Siheng Wang, Le Yu, Shanshan Wang, Lei Zhang, Lu Chen, Xu Xu, Zhanqian Song, He Liu, Chaoji Chen