Synthesis of binary nanoparticle superlattices has attracted attention for a broad spectrum of
potential applications. However, this has remained challenging for one-dimensional nanoparticle
systems. In this study, we investigate the packing behavior of one-dimensional
nanoparticles of different diameters into a hexagonally packed cylindrical micellar system and
demonstrate that binary one-dimensional nanoparticle superlattices of two different symmetries
can be obtained by tuning particle diameter and mixing ratios. The hexagonal arrays
of one-dimensional nanoparticles are embedded in the honeycomb lattices (for AB2 type) or
kagome lattices (for AB3 type) of micellar cylinders. The maximization of free volume entropy
is considered as the main driving force for the formation of superlattices, which is well
supported by our theoretical free energy calculations. Our approach provides a route for
fabricating binary one-dimensional nanoparticle superlattices and may be applicable for
inorganic one-dimensional nanoparticle systems.