Spotlights on Recent JACS Publications

摘要

It is easy to braid hair, but what about braiding a nanowire? That is the task Hongyu Chen and co-workers set out to accomplish, inspired by the enhanced mechanical strength of fibers braided into rope (DOI: 10.1021/jacs.0c03445). But one cannot just pick up nanowires and weave them into intricate patterns. So the researchers developed a method that essentially tricks the wires into braiding themselves. They synthesized gold nanowires that are dispersed in a solution, then switched to a more polar solvent that caused them to aggregate into bundles 50 nm to about 2 μm in diameter. Next, they deposited palladium on the nanowires, which elevated them to a high-energy state that caused them to twist into braided nanoropes in order to relax their internal strain and reach a lower energy state. As a twisting nanowire would deform and "persuade" its neighbors to twist toward the same direction, it explains the common twisting direction that is essential for the braiding. These nanoropes were slimmer than the original aggregates, at 20-30 nm in diameter on average. Such spontaneously braided nanoropes could allow chemists to remotely control energy transmission in these systems, and could be promising components of future nanodevices. Deirdre Lockwood Ph.D.