Exploring the impact of surface ligands on self-assembly indicates the potential of a delicate controlled structures, which favors the various relevant applications through collective properties of assembled independent NPs. We demonstrate for the first time a co-assembly of Metal Organic Framework (MOF) and Iron Oxide (Fe3O4) nanoparticles, which is mediated by surface ligands on Fe3O4 nanoparticles. In the co-assembly process by adding a mixture solution of Fe3O4 and MOF NPs onto a liquid-air interface, the oleic acid capped Fe3O4 NPs initially formed a superlattice template which enhanced a single layered MOF film co-assemble on its top, resulting a 2D double-layered superstructure. When the surface ligands of Fe3O4 NPs were exchanged to polystyrene (PS), Fe3O4 and MOF NPs randomly assembled into single-layered structure. STEM/EDX and three-dimensional tomography reconstruction images have confirmed the different hierarchical structures formed by co-assembly of Fe3O4 NPs and MOF NPs with different capping ligands. By varying the experimental conditions, we found that the different self-assembly processes could be mediated by the surface ligands of Fe3O4 NPs. First principle calculations and Monte Carlo (MC) simulations were used to understand the different self-assembly behaviors, which further confirmed our hypothesis on ligand-mediated self-assembly. This study opens a new avenue for co-assembly of MOF NPs with inorganic NPs for functional materials, and provides deep kinetic understanding on self-assembly.
See more of this Session: Self and Directed Assembly at the Nanoscale
See more of this Group/Topical: Nanoscale Science and Engineering Forum
See more of this Group/Topical: Nanoscale Science and Engineering Forum