Silver nanoparticle/nanocellulose composites antibacterial strain-responsive hydrogels

The antibacterial and conductive hydrogels based on silver nanoparticles (AgNPs) have important applications in wearable devices, electronic skin, biosensors, and other areas, and their green manufacturing is currently the focus of much research. Nanocellulose has attracted more attention relating to the preparation and application of the smart hydrogels due to its unique physico-chemical properties. When AgNPs are combined with nanocellulose and applied to hydrogels, it is expected to lead to fabrication of antibacterial hydrogels with good mechanical properties, which has guiding significance for the application of hydrogels in the area of intelligent wearable systems. In the present study, AgNPs/nanocellulose composites (Ag-CNF) were in situ synthesized using TEMPO-oxidized nanocellulose (TOCNF) as a composite substrate and silver nitrate (AgNO₃) as a source of silver. Ag-CNF and tannic acid (TA) were introduced to polyacrylamide (PAM) hydrogels as functional additives to prepare the Ag-CNF/PAM hydrogel (AP hydrogel) with good tensile properties, adhesion, antibacterial properties, and UV-shielding properties. The AP hydrogels were then packaged into a strain-responsive sensor. The electrical and sensing properties were studied. AP hydrogels can maintain stable and repeated electrical output under 100% strain cycle and can also be used for wrist motion and head motion detection, which has potential for use as a strain-responsive sensor.