title: Ionogel-templated synthesis and organization of anisotropic gold nanoparticles.
abstract: Photochemical reduction of tetrachloroaurate (AuCl4-) ions in the highly constrained aqueous domains of a nanostructured ionogel template, formed via self-assembly of the ionic liquid 1-decyl-3-methylimidazolium chloride (C10mim+Cl-) in water, results in the formation of anisotropic gold nanoparticles with a variety of sizes and morphologies, which include previously unattainable trigonal prismatic nanorods. Unexpectedly, small-angle X-ray scattering studies of the Au-ionogel composite reveal that the in situ formation of the nanoparticles increases the mesoscopic order of the ionogel, which results in its conversion to a near-monodomain structure. The findings demonstrate that nanostructured, ionic liquid-based gels can be used to template the formation of new nanoparticle morphologies with technologically important optical, electronic, and catalytic properties. It may also be possible to design soft templates that permit the fabrication of highly ordered nanoparticle array-hydrogel composites, thereby enabling control and tuning of the collective properties of the encapsulated nanoparticles.
authors.affiliation: Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA. firestone@anl.gov
authors.forename: Millicent A
authors.initials: MA
authors.lastname: Firestone
authors.forename: Mark L
authors.initials: ML
authors.lastname: Dietz
authors.forename: Sönke
authors.initials: S
authors.lastname: Seifert
authors.forename: Susana
authors.initials: S
authors.lastname: Trasobares
authors.forename: Dean J
authors.initials: DJ
authors.lastname: Miller
authors.forename: Nestor J
authors.initials: NJ
authors.lastname: Zaluzec
mesh_terms: D016880:Anisotropy; D005782:Gels / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles; D049329:Nanostructures; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods*; D043942:Nanotubes; D012542:Scattering, Radiation; D013499:Surface Properties; D014466:Ultraviolet Rays; D014965:X-Rays
chemical_list: D005782:Gels; D052578:Ionic Liquids; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D006046:Gold