Optimizing Silver Nanowire Synthesis for In-Body Applications

This work presents a parametric study for optimizing the synthesis of silver nanowires (AgNWs) using a polyol method for in-body applications. The effects of various parameters, including reaction time, reaction temperature, and type of metal halide employed during synthesis, on the properties of the AgNWs are systematically investigated. The kinetics of AgNW formation are analyzed by temporal UV-vis spectroscopy and TEM. To elaborate on the complexity of the metal halide employed during the production of silver nanowires, we have conducted various sets of experiments, revealing the role of the metal in classical polyol synthesis. We have demonstrated that even though the stoichiometric ratio of Ag+/Cl- is kept constant, the type of halide source is directly related to the formation of high-yield silver nanowires. The AgNW/P(AAm-co-AAc-co-PEGDA) hydrogel synthesized with as-produced AgNWs demonstrates suitable mechanical and electrical properties for in-body sensors, particularly for pH monitoring. Its electrical behavior exhibits frequency-dependent conductivity enhancements attributed to polarization mechanisms, but conductivity decreases with increasing pH due to ionization and structural changes within the hydrogel.