Ligand-Induced Incompatible Curvatures Control Ultrathin Nanoplatelet Polymorphism and Chirality
arXiv:2308.11505 · doi:10.1073/pnas.2316299121
Abstract
The ability of thin materials to shape-shift is a common occurrence that leads to dynamic pattern formation and function in natural and man-made structures. However, harnessing this concept to design inorganic structures at the nanoscale rationally has remained far from reach due to a lack of fundamental understanding of the essential physical components. Here, we show that the interaction between organic ligands and the nanocrystal surface is responsible for the full range of chiral shapes seen in colloidal nanoplatelets. The adsorption of ligands results in incompatible curvatures on the top and bottom surfaces of NPL, causing them to deform into helicoïds, helical ribbons, or tubes depending on the lateral dimensions and crystallographic orientation of the NPL. We demonstrate that nanoplatelets belong to the broad class of geometrically frustrated assemblies and exhibit one of their hallmark features: a transition between helicoïds and helical ribbons at a critical width. The effective curvature is the single aggregate parameter that encodes the details of the ligand/surface interaction, determining the nanoplatelets' geometry for a given width and crystallographic orientation. The conceptual framework described here will aid the rational design of dynamic, chiral nanostructures with high fundamental and practical relevance.
16 pages, 8 figures
References in corpus (5)
- Perspective: Geometrically-Frustrated Assemblies
- Shape Selection in Chiral Self-Assembly
- Building blocks of non-Euclidean ribbons: Size-controlled self-assembly via discrete, frustrated particles
- Ligand-Induced Incompatible Curvatures Control Ultrathin Nanoplatelet Polymorphism and Chirality
- Spontaneous strain in quasi-two-dimensional Janus CdSe nanoplatelets and its microscopic mechanisms