Continuous Flow Synthesis of Metal Nanowires: Protocols, Engineering Aspect for Scale-up and Applications

Abstract

This review comprehensively covers the translation from batch to continuous flow synthesis of metal nanowires (i.e. silver, copper, gold, and platinum nanowires) and its diverse applications across various sectors. Metal nanowires have attracted significant attention owing to their versatility and feasibility for large-scale synthesis. The efficacy of flow chemistry in nanomaterial synthesis has been extensively demonstrated over the past decade. Continuous flow synthesis offers scalability, high throughput screening, and robust and reproducible synthesis procedures, making it a promising technology. Silver nanowires, widely used in flexible electronics, transparent conductive films, and sensors, have seen advancements in continuous flow synthesis aimed at achieving high aspect ratios and uniform diameters, though challenges in preventing agglomeration during large-scale production remain. Copper nanowires, considered a cost-effective alternative to silver for conductive materials, have benefited from continuous flow synthesis methods that minimize oxidation and enhance stability, yet scaling up these processes requires precise control of reducing environments and copper ion concentration. A critical evaluation of various metal nanowire ink formulations is conducted, aiming to identify formulations that exhibit superior properties with lower metal solid content. The study delves into the intricacies of continuous flow synthesis methods for metal nanowires, emphasizing the exploration and engineering considerations essential for the design of continuous flow reactors. Furthermore, challenges associated with large-scale synthesis are addressed and highlights the process-related issue.