Quaternization-Assisted Assembly of Polymer-Tethered Gold Nanoparticles into Superlattices with a Tunable Structure

Abstract

Programmable organization of functional inorganic nanoparticles (NPs) into well-defined hierarchical superstructures has raised considerable concern due to the enhanced magnetic, electronic, and optical properties arising from the strong plasmonic coupling effect. However, the spontaneous self-assembly of inorganic NPs into uniform superlattices with the desired or tunable shape remains a formidable challenge. Herein, we report the quaternization-assisted hierarchical assembly of gold nanoparticles (AuNPs) tethered with polystyrene (PS) and quaternized poly(2-vinylpyridine) (P2VP) ligands into controllable superstructures in emulsion droplets. The quaternization interaction between bromoalkyl molecular additives (e.g., CnH2n+1Br) and P2VP ligands results in the increase of the hydrophilicity degree of quaternized P2VP ligands and triggers the interfacial instability of emulsion droplets, achieving the continuous transformation of generated superstructures from solid assemblies to hollow colloidosomes and then to the multilayer sheet-like superlattices. Furthermore, the degree of quaternization can be readily tuned by the added content of additives and the length of the alkyl chain, providing a unique and promising approach to prepare contrivable superstructures and functional materials.