Kinetic analysis of silver nanowire synthesis: polyol batch and continuous millifluidic methods

Abstract

This study investigates the variation in rate constants for nucleation and growth of silver nanowires (AgNWs) synthesized using the polyol method in batch and millifluidic flow reactors (MFRs). In a particular reactor, silver ion concentration at any time is quantified by the method of El-Ghamry et al. and the non-linear two-step Finke–Watzky model is used to determine the rate constants for nucleation (k₁) and growth (k₂). The results indicate that k₁ and k₂ for the MFRs are approximately four and two times larger, respectively, than the batch reactor rate constants. Additionally, the concentration, yield, and diameter of the synthesized AgNWs were determined using ultraviolet-visible (UV-vis) spectroscopy data. The results indicated that the concentration and yield of AgNWs synthesized using the MFR were approximately 10 times higher than those obtained with the batch reactor. Overall, AgNW synthesis in MFRs is about three times faster than the batch reactor. The coiled configuration of the MFRs promotes AgNW growth, minimizes temperature transients, and enhances reagent mixing caused by Dean vortices. This study highlights the potential of MFRs for the continuous synthesis of AgNWs and provides insights into the underlying growth mechanism.