Polyol Silver Nanowire Synthesis and the Outlook for a Green Process

Abstract

Silver nanowires (AgNWs) have a broad range of applications including nanoelectronics, energy conversion, health care, solar cells, touch screens, sensors and biosensors, wearable electronics, and drug delivery systems. As their characteristics depend strongly on their size and morphology, it is essential to find the optimal and most cost-effective synthesis method with precise control over the size and morphology of the wires. Various methods for AgNW synthesis have been reported along with process optimization and novel techniques to increase the yield and aspect ratios of synthesized AgNWs. The most promising processes for synthesis of AgNWs are wet chemical techniques, in which the polyol process is low cost and simple and provides high yield compared to other chemical methods. Reaction mechanism is one of the most important factors in strategies to control the process. Our purpose here is to provide an overview on the main findings regarding synthesis, preparation, and characterization of AgNWs. Recent efforts in the polyol synthesis of AgNWs are summarized with respect to product morphology and size, reaction conditions, and characterization techniques. The effect of essential factors such as reagent concentration and preparation, temperature, and reaction atmosphere that control the size, morphology, and yield of synthesized AgNWs is reviewed. Moreover, a review on the novel modified polyol process and reactor design such as continuous millifluidic and flow reactors to increase the yield of synthesized AgNWs on large scales is provided. The most recent proposed growth mechanisms and kinetics behind the polyol process are addressed. Finally, comparatively few available studies in green and sustainable development of 1D silver nanostructures through the application of natural products with inherent growth termination, stabilization, and capping characteristics are reviewed to provide an avenue to natural synthesis pathways to AgNWs. Future directions in both chemical and green synthesis approaches of AgNWs are addressed.

Statistically Optimized Production of Saccharides Stabilized Silver Nanoparticles Using Liquid–Plasma Reduction Approach for Antibacterial Treatment of Water

“…Various methodologies have been reported in the literature to synthesize metal nanoparticles, including hydrothermal method [ 6 ], sol-gel method [ 7 ], photodetection technique [ 8 ], ultraviolet irradiation method [ 9 ], electrochemical technique [ 10 ], porous materials template [ 11 ], solvothermal method [ 12 ], chemical synthesis [ 13 ], microwave plasma treatment [ 14 ], polyol process [ 15 ], green synthesis [ 16 , 17 ] coaxial electro-spinning [ 18 ] and liquid plasma interaction technique [ 19 ]. Each approach has its own set of advantages and disadvantages, including differences in process cost, quantity, functionality and particle size distribution.…”

A review on the green and sustainable synthesis of silver nanoparticles and one-dimensional silver nanostructures

“…While progress with improving the polyol process is ongoing, some studies started to use green reagents for the synthesis of AgNWs. We have recently reviewed the polyol silver nanowire synthesis and its outlook for a green process [ 367 ]. In 2009, Tian et al synthesized single-crystalline AgNWs – 25 nm in diameter and 20 µm in length – using tannin acting as both reducing and capping agent [ 368 ].…”

Recent Advances in High-Throughput Nanomaterial Manufacturing for Hybrid Flexible Bioelectronics

“…Nanowires are traditionally synthesized through the polyol method for printed inks, but the template method is also widely employed [ 11 , 17 , 113 ]. In polyol synthesis, the solution temperature, PVP molar ratio to AgNO 3 , stirring rate, the introduction of platinum seeds or other nucleation agents, and the addition of chloride or bromide ions can all be used to control the material dimensions and AgNW quality [ 93 , 113 , 114 ]. Figure 7 a shows SEM images of AgNWs synthesized in various PVP solutions along with quantitative measurements of average NW diameter and length, and this experiment demonstrates that PVP solutions must be carefully optimized for Polyol synthesis [ 93 ].…”

“…Figure 7 a shows SEM images of AgNWs synthesized in various PVP solutions along with quantitative measurements of average NW diameter and length, and this experiment demonstrates that PVP solutions must be carefully optimized for Polyol synthesis [ 93 ]. During this synthesis method, AgNWs are typically produced from Ag seeds reduced from AgNO 3 , and these seeds are capped by the presence of PVP [ 93 , 114 ]. Although the exact mechanism by which AgNWs are synthesized in the polyol process is not fully known, it is likely that the differential affinity of PVP to the <100> plane than <111> plane in silver leads to unidirectional growth [ 115 ].…”