Polymer Corona Engineering for Programmable Emulsion Assembly of Gold Nanoparticles

The 3D assembly of polymer-grafted nanoparticles (PGNPs) offers a versatile platform for constructing ordered suprastructures whose symmetry and morphology are governed by polymer corona interactions and emulsion confinement. In this study, we investigate two complementary strategies to control the assembly behavior of polystyrene-grafted Au nanoparticles (Au@PS NPs). First, Au NPs bearing hybrid PS/P4VP polymer ligands are examined to understand how chemical heterogeneity within the grafted corona influences interparticle interactions, surfactant-mediated interfacial behavior, and crystallization pathways under emulsion confinement. By tuning the PS/P4VP composition, the balance between corona miscibility, particle packing, and confinement-driven ordering can be modulated, leading to changes in supraparticle morphology and internal structure. Second, PS homopolymer is blended with Au@PS NPs as a physical additive to alter the local polymer environment surrounding the grafted NPs. The added homopolymer can modify effective corona softness, brush overlap, and interparticle spacing, thereby providing a simple route to regulate supracrystal formation without changing the covalently grafted ligand structure. Together, these studies demonstrate that both hybrid polymer ligands and free polymer additives serve as effective molecular handles for programming the emulsion assembly of PGNPs into tunable 3D suprastructures.