title: Two-dimensional self-assembly of hydrophobic nanoparticles at oil/water interfaces via nanoscale phase separation of mixed ligands.
abstract: Hydrophobic nanoparticles were assembled into large-area monolayer films by combining oil/water interfacial self-assembly and phase separation of mixed ligands. Mixed ligands-capped nanoparticles were prepared simply by partially replacing the initial ligands of nanoparticle surfaces with polyvinylpyrrolidone (PVP). Infrared spectra and X-ray photoelectron spectroscopy demonstrate that O atom of PVP binds to the nanoparticle surface, changing the wettability of the nanoparticle. By controlling the polarity of solvent, nanoparticles can spontaneously migrate to toluene/water interfaces, forming large-area, close-packed monolayer films. This approach provides a straightforward way to fabricate nanoparticle films with a centimeter-scale size without LB trough, and may have potential applications in the fabrication of catalytic electrodes and photovoltaic electrodes.
authors.affiliation: State Key Lab of Chemo/Biosensing and Chemometrics, School of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China. budabuxiaohao@126.com
authors.forename: Sheng-Jun
authors.initials: SJ
authors.lastname: Liu
authors.forename: Yong-Jun
authors.initials: YJ
authors.lastname: Li
authors.forename: Yu-Mei
authors.initials: YM
authors.lastname: Wang
authors.forename: Xiu
authors.initials: X
authors.lastname: Liu
authors.forename: Edward S
authors.initials: ES
authors.lastname: Yeung
keywords: Hydrophobic nanoparticle; Ligand exchange; Monolayer film; Phase separation; Self-assembly