Sugarcane liquid-generated silver nanoparticles connected ionic polymer nanocomposite for enhanced electrical and wearable sensing signals

Abstract

Metal nanoparticles (NPs) bonded ionic polymer nanocomposite (IPNC) is required in wearable sensors, structural health monitoring, actuators, fuel cells, batteries, water purifiers, and supercapacitor applications due to their high gauge factor, high conductivity, and high mechanical strength. In this study, a cost-effective IPNC was developed with the bonding of Ag NPs in polyvinyl alcohol (PVA)/sugarcane (SCN) liquid-based ionic polymer (IP). The SCN liquid was used as a reducing agent for converting AgNO3 into Ag and Ag2O NPs into the backbones of PVA and finalized IP/AgNO3-based IPNC with weight ratios of 1/0.3, 1/0.5, and 1/0.7, respectively. The proposed IPNC 1/0.3 generated high sensitivity (ΔR/R) (5.7) and highest gauge factor (G) (307) compared to the existing polyurethane/cellulose/silver nanowire, polyurethane/Ag flakes, and polytetrafluoroethylene-Ag conductors composites. The 1/0.3-based IPNC generated highest ionic conductivity among all the IPNCs and depicted 4 times and 150 times higher than that of the IP and pure PVA polymer due to the uniform distribution of NPs with diameters between 18 and 53 nm in the backbone of the 1/0.3-based IPNC. The 1/0.3-based IPNC showed higher electrical current (14 mA/cm2) and capacitance (700 mF/cm2) than that of the commercial platinum-coated Nafion, polyelectrolytes, and ionic liquid-based IPNC due to the high water uptake (1.34); low contact angle (40°); and S, O, Ag, and Ag2O NPs elements on its surface. The piezoresistive sensing signals from 1/0.3-based IPNC were observed by placing them on the finger and neck. It generated sensing signals on bending of the finger, chin up, chin down, breathing, and coughing, respectively. The cost-effective Ag-attached PVA/SCN IPNC can be utilized in industrial applications such as fuel cells, batteries, water purifiers, wearable sensors, actuators, and supercapacitors. © 2022 Elsevier Ltd