Bulk Nanostructured Metal from Multiply-Twinned Nanowires

Area of Science:

• Materials Science
• Nanotechnology
• Metallurgy

Background:

• Chemically synthesized silver nanowires (AgNWs) with 5-fold twinning planes offer a scalable route to high-twinning-density Ag particles.
• Developing bulk nanostructured metals from nanowires presents challenges in maintaining structure during densification.

Purpose of the Study:

• To demonstrate a bottom-up process for generating bulk nanostructured metal using silver nanowires.
• To overcome challenges in nanowire densification and achieve a cohesive bulk material.

Main Methods:

• Silver nanowires were synthesized and used as a model system.
• Initial attempts involved cold pressing and hot pressing without binders, leading to deformation and sintering.
• Copper was applied via electroplating and electroless plating as a binder and filler to enhance densification.

Main Results:

• Direct pressing of silver nanowires resulted in insufficient cohesion and loss of morphology.
• Electroplating copper improved thermal stability, allowing hot pressing at higher temperatures, but plating was non-uniform.
• Electroless plating achieved uniform copper coating, enabling the formation of cohesive bulk metal after hot pressing.

Conclusions:

• A successful bottom-up approach to fabricate bulk nanostructured metal from silver nanowires was developed.
• Uniform copper coating is crucial for achieving cohesive bulk metal by preventing nanowire deformation and sintering during hot pressing.