Research On Synthesis And Purification Of Ultrafine Silver Nanowires

With the continuous advancement of technology,electronic products continue to develop in a lighter,thinner,and more flexible direction.Manufacturing screens that meet their needs is a current research hotspot.The key to this technology is transparent conductive film.At present,research on transparent conductive films is mainly focused on ITO materials.ITO films are brittle,high in price and scarce in quantity,and the preparation equipment is expensive.The transparent conductive film made of silver nanowires has good bending resistance,high conductivity,high transmittance and low haze.The three key parameters of the silver nanowire transparent conductive film are transmittance,resistance and haze,which correspond to the diameter,length and purity of the silver nanowire.Therefore,it is very necessary to develop a method for preparing and purifying ultrafine silver nanowires with an aspect ratio.Aiming at the problem that it is difficult to synthesize silver nanowires in large quantities,this paper first explored the experimental parameters of the synthesis of silver nanowires using polyol method,such as temperature,reaction time,Na Cl,Na Br amount,etc.,and analyzed the reaction mechanism in the reaction process of silver nanowires.This paper expant 10 times and the synthesis of the original system;explored the mass amplification phenomenon in the process of synthesis of silver nanowires;and finally improved the parameters in the process of synthesis,optimized the synthesis of large quantities of silver nanowires,made it in 500 m L system realizing stable synthesis.Finally in 500 m L system,silver nanowires in 30 nm in diameter,the length of 31 ?m,length-diameter ratio of more than 1000 Silver nanowires were synthesized.They have good repeatability,high stability,and for the subsequent further lay the foundation for industrial application.For high length-diameter ratio,superfine silver nanowire fabrication processes immature problem,this paper based on the existing silver nanowires synthesis plan synthesized silver nanowires,by adjusting the additive type,the original inorganic Na Cl and Na Br replaced by CTAB,CTAC and a series of organic matter,by adjusting the parameters.The synthesis of silver nanowires average diameter is 22.3 nm,the minimum diameter of 13.96 nm,length more than 23 ?m,and the length-diameter ratio is greater than 1000.The synthesis mechanism of silver nanowires was further explored by comparing the synthesis process of organic and inorganic auxiliaries.In addition,this thesis of silver nanowires in the process of synthetic intermediate,was analyzed,and the pioneering presend a synthesis method of silver nanowires through three steps.The first step is to get the silver halide precursors,as subsequent superfine silver nanowires synthetic seed;the second step is to uss ammonia etching,seed size,and then adjust the silver nanowire diameter;the third step is to use seed silver nanowires subsequent growth.Finally,the ultrafine,ultra-high length-diameter ratio and clean silver nanowires with diameter of 20 nm,length of 37 ?m and aspect ratio up to 1800 were obtained.To solve the problems in the purification of ultrafine silver nanowires,this paper adopts two methods: purification of the synthesized mother liquor and purification during the synthesis process.During the purification of the raw liquor,impurities in the raw liquor are effectively removed by centrifugation,acetone and complexing agent.In the synthesis process,water has a great influence on the purification of raw materials.The reason of impurities produced by water in the synthesis process was explored.The purpose of water removal was achieved by means of nitrogen bubble under the vacuum condition,thus the purification of silver nanowires was realized.