Preparation Of Silver Nanowires And Their Application In Conductive Adhesive

The smaller size of the silver nanomaterial owns highly specific surface area,which can make the silver nanomaterial has special physical, chemical andmechanical properties. Silver nanomaterial is widely used in fields ofelectro-conductive paste, optical devices, catalysis, and pharmaceuticals at present.The diameter, size and morphology parameters of nanomaterial have a significantimpact to its electrical, thermal and optical properties. So the control synthesis ofdifferent forms silver nanomaterial, including particles, rods and nanowires, is ofgreat importance.This article explored one step-polyol reduction method to prepare the silvernanomaterial and mainly investigated the experimental reduction system in ethyleneglycol and glycerol. In both reaction systems, the process parameters such as themolar ratio of PVP and AgNO3, reaction temperature and time, AgNO3concentration, PVP molecular weight, reaction atmosphere, control agent addingand etc are investigated to confirm these parameters have impacted on morphologyand structure of the product. After a series of experiments, the article developed thesystem in ethylene glycol reduction of silver nanorods prepared under optimalexperimental program and in glycerin system silver nanowires prepared underoptimal experimental program. In this thesis, the morphology and structure ofproduct are systematically characterized. Research shows that products have aface-centered cubic stucture of metallic silver, good crystallinity and uniform size.The average length of silver nanorods is2-5μm, and the average diameters are100-200nm. The average length of silver nanorods is10-15μm, and the averagediameters are60-100nm. The results of amplifying experiment of these twoprograms show that the size of the amplified product after the experiment is notparticularly uniform because of a small number of particles, but roughly themorphology of the product is general same. It can be output oriented, but requiresfurther optimized and improves in future.This article found a way that added a sort of etchant in the preparation of silvernanorods glycol systems can sculpture the twin crystal nucleus before it grows upinto silver nanowire in initial response force. This can lead to the decrease of silvernanowire and the increase of silver nanoparticle in final product.Silver conductive adhesive is an important application of silver nanomaterial.Conductive property is essential and the most important performance of silverconductive adhesive. Silver nanoparticles with different morphologies as aconductive filler can improve the conductivity of conductive adhesive. Studies have shown that using the large partlcles silver powder as the main filling materials andadding a certain amount of silver nanorod and silver nanowire can improve theconductivity. Because the silver nanorods can be filled in the gap of silver flake andbe used as a short ride associated conductive paths, to increase conductive paths andform the conductive network. It can help to reduce the volume resistivity ofconductive adhesive. The nanoparticles can be filled in a non-contact area of silverflake and nanorods, and it will make more perfect conductive network, therebyreducing the volume resistivity of conductive adhesive.