title: Self-assembly of a hexagonal phase of wormlike micelles containing metal nanoclusters.
abstract: Stable nanoclusters (approximately 2 nm in diameter) of copper, silver, gold, palladium, and ruthenium coated with hydrophobic coronas are easily trapped in self-assembled "soft crystal" hexagonal phase gels made of water and surfactants. The system's crystal structure and phase behavior are studied in detail. A partial phase diagram showing the hexagonal phase region for the water/SDS/toluene region is presented. High-energy X-ray scattering and cross-polarized optical microscopy experiments show that the clusters are tightly confined within the tubes. The thermal gel-fluid transitions of the hexagonal phase are investigated, and it is shown that the hexagonal phase can melt and recrystallize repeatedly. The melt/gel cycles enable easy trapping of various metal clusters in pre-prepared hexagonal phases. In contrast to spherical micelles, the hexagonal phase doped with metal clusters can grow without limit, basically up to the container walls (Ru-doped soft crystals grew to 0.5 mm over 2 months, forming wormlike tubes that are more than 50 microm long but only 7-10 nm in diameter).
authors.affiliation: Chemical Engineering Department, University of Amsterdam, 1018 WV Amsterdam, The Netherlands.
authors.forename: Fatima
authors.initials: F
authors.lastname: Bouchama
authors.forename: Mehul B
authors.initials: MB
authors.lastname: Thathagar
authors.forename: Gadi
authors.initials: G
authors.lastname: Rothenberg
authors.forename: Daan H
authors.initials: DH
authors.lastname: Turkenburg
authors.forename: Erika
authors.initials: E
authors.lastname: Eiser