The smart growth of self-assembled silver nanoloops

Abstract

Enclosed silver nanoloops have unique features in manipulating and controlling light. However, even the conception of their growth mechanism has not been established. The intermediate structure at the growth stage were revealed as the crucial issue for studying their smart growth mechanism of silver nanoloops and nanowires. Early growth stage showed that silver nanorods and nanoparticles were grown in their respective polyvinylpyrrolidone micelles. Then, the silver nanorods and nanoparticles were assembled in a rod–particle–rod pattern via micelle–micelle coupling, forming linear silver nanowires. These silver nanowires were attracted by Van der Waals forces forming the initial nanoloop. Notably, there was a silver nanoparticle between the ends of two adjacent nanowires. This silver nanoparticle acted like solder and played a crucial role in connecting the two adjacent nanowires; consequently, a silver nanoloop was formed. This finding also suggested that similar smart growth patterns might exist for other one-dimensional and looped nanomaterials.