Polymorphous Packing of Pentagonal Nanoprisms

Abstract

Packing solid shapes into regular lattices can yield very complex assemblies, not all of which achieve the highest packing fraction. In two dimensions, the regular pentagon is paradigmatic, being the simplest shape that does not pave the plane completely. In this work, we demonstrate the packing of plasmonic nanoprisms with pentagonal cross section, which form extended supercrystals. We do encounter the long-predicted ice-ray and Dürer packings (with packing fractions of 0.921 and 0.854, respectively) but also a variety of novel polymorphs that can be obtained from these two configurations by a continuous sliding transformation and exhibit an intermediate packing fraction. Beyond the fundamental interest of this result, fine control over the density and symmetry of such plasmonic assemblies opens the perspective of tuning their optical properties, with potential applications in metamaterial fabrication, catalysis, or molecular detection.

Prismatic Confinement Induces Tunable Orientation in Plasmonic Supercrystals

“…The results demonstrate the growth of multiple crystal domains influenced by the mold’s interface, where each side directs the growth of a monodomain until it encounters another, resulting in grain boundary formation. Since our approach for orienting supercrystals works for AuNRs and AuBPs, we hypothesize that it can be generalized to NPs superlattices of other relevant shapes such as pentagonal nanoprisms, platonic solids , and nanoplatelets . Although cylindrical microcavities do not allow controlling of the orientation of anisotropic colloids, this work shows that prismatic cavities are promising to orient such nanoparticles on a substrate.…”

Self-Assembled Bimetallic Au–Ag Nanorod Vertical Array for Single-Molecule Plasmonic Sensing

“…Hybrid plasmonic nanostructures, such as bimetallic Au–Ag nanoparticles, are being recognized as excellent SERS substrates due to the unique combination of the enhanced plasmonic properties of Ag and the chemical stability of Au within a single structure. − Au–Ag bimetallic systems, with their enhanced optical properties, have been widely studied for a diverse range of both SERS- and non-SERS-based applications. − For instance, spherical and nanodumbbell-shaped Au@Ag core–shell nanostructures have been utilized in single-molecule SERS studies. , So far, most of the research was focused on either individual or substrate drop-casted nanoparticles where the distribution of hotspots is not uniform and scanning is required for getting high EFs. While there have been notable instances of self-assembled bimetallic nanostructures reported in the literature, − a comprehensive investigation into a well-organized array of Au–Ag nanorods remains an area of continued interest and active exploration within the scientific community. In particular, there are two reasons to explore self-assembled bimetallic nanostructures for SERS.…”

Local Confinement Effects of Block Copolymers Driving Self‐Assembly of Nanoparticles into Discrete Pancake‐Shaped Superlattices

“…The self-assembly of nanoparticles (NPs) represents a cuttingedge approach in materials science, enabling the design of novel materials with bespoke structures and functionalities. [1] Unlike traditional methods that rely primarily on altering size and morphology of building blocks, [2,3] and other straightforward parameters to modulate assembly behavior and structure, the manipulation of surface ligands on NPs presents a more nuanced and effective strategy for control. [4] Specifically, the employment of polymeric ligands, including homopolymers and block copolymers, with their versatile spatial configurations, empowers researchers to tailor the surface properties of NPs.…”