Preparation And Applications Of Silver Nanowires And Networks

Silver nanowires with high selectivity and high aspect ratio were synthesized by the polyol method in our study. Different control agents were used here to improve the traditional two-step polyol methods, such as anionic control agent, cationic control agent and molecular control agent. For the anionic and molecular agents, they could nucleate very fast in the solution and provide the seed for the growth of the silver nanowires.The whole reaction would need only one step without the seeding period, while its selectivity and reproducibility could be improved prominently. By using anionic and molecular control agent, the synthetic silver nanowires usually have a diameter larger than 100nm. But using cationic agent could bring some silver nanowires with a diameter usually less than 100nm. By taking advantage of Mn2+, Fe3+, Co2+, Cd2+and so on combined with anionic control agent, silver nanowires could be synthesized in good selectivity and high efficiency even if the precursor concentration was increased to 0.5M and the reaction time could be reduced in 30min.Except for the polyol method, we had also synthesized a kind of silver nano-assembly through reverse micellar solution, which could be further processed into silver nanowires. In this reverse micellar system, MMA was used as the oil phase, AgNO3 and NaBH4 solution were used as the aqueous phase and carboxylic acids with the straight chain were used as surfactant here. By adopting different carboxylic acids, the silver nano-assembly with different morphology would be obtained and the assembled silver nanoparticles would have a decreasing diameter with the chain length of the carboxylic acid increasing. In addition, a kind of novel tubular network assembly would be obtained in the presence of lauric acid, while the silver nanosheets with different roll degree would be synthesized in the other carboxylic acids.Subsequently, the silver nanowires with the mean diameter ca.80nm synthesized in the polyol method were used as template to guide the growth of gold nanotubes, which showed good application potentials in the fuel cell. By taking advantage of the synergistic promotion both from the surfactant and saturated NaCl solution, the Au-Ag bimetallic nanotubes were synthesized with smooth surface and uniform shell thickness in good dispersion. Futhermore, the resultant product could reserve the morphological characteristics derived from the silver template as well. In addition, silver nanowires were also mixed into the micro-sized silver condutive filler and then added into one two-component silicon urethane varnish. Through this action, one kind of high-performance conductive coating was fabricated and this coating was expected to be applied onto the surface of airplane so as to provide the effective anti-lightning protection.