title: Nanoparticle assembly at fluid interfaces: structure and dynamics.
abstract: The self-assembly of nanoparticles at fluid interfaces, driven by the reduction in interfacial energy, was investigated. With spherical, tri-n-octyl-phosphine-oxide covered cadmium selenide (CdSe) nanoparticles (1-8 nm), thermal fluctuations compete with the interfacial segregation giving rise to a size-dependent self-assembly of the particles. The structure of the nanoparticle assembly was studied using electron microscopy, atomic force microscopy, and X-ray scattering in situ, which indicate that the particles form a densely packed monolayer. The energetics of the adsorption of nanoparticles onto the interface was revealed by time-dependent fluorescence studies on a mixture of two different sized nanoparticles at the interface. The dynamics of the nanoparticles at the fluid interface, probed using fluorescence photobleaching methods, suggests a liquid-like behavior. The results have implications in the design of hierarchical self-assemblies of nanoparticles for the one-step fabrication of devices on multiple length scales.
authors.affiliation: Department of Polymer Science and Engineering, University of Massachusetts, Amherst, MA 01003, USA.
authors.forename: Yao
authors.initials: Y
authors.lastname: Lin
authors.forename: Alexander
authors.initials: A
authors.lastname: Böker
authors.forename: Habib
authors.initials: H
authors.lastname: Skaff
authors.forename: David
authors.initials: D
authors.lastname: Cookson
authors.forename: A D
authors.initials: AD
authors.lastname: Dinsmore
authors.forename: Todd
authors.initials: T
authors.lastname: Emrick
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Russell