Advanced Materials

Cover image for Vol. 18 Issue 15

August, 2006

Volume 18, Issue 15

Pages 1931–2058

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Reviews
    6. Communications
    7. Research News
    8. Index
    1. Cover Picture: Fabrication of Stable Low-Density Silica Aerogels Containing Luminescent ZnS Capped CdSe Quantum Dots (Adv. Mater. 15/2006)

      L. Sorensen, G. F. Strouse and A. E. Stiegman

      Article first published online: 27 JUL 2006 | DOI: 10.1002/adma.200690061

      Luminescent CdSe quantum dots of 2.5 and 6.0 nm dimension have been incorporated into a low-density silica aerogels matrix. The aerogels are formed from the supercritical CO2 extraction of an alcogel containing quantum dots surface passivated with 3-aminopropyltriethoxysilane. The resulting aerogels (see figure and cover) are low scattering and show intense, stable luminescence.

  2. Inside Front Cover

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Reviews
    6. Communications
    7. Research News
    8. Index
    1. Inside Front Cover: Direct Printing of 3D and Curvilinear Micrometer-Sized Architectures into Solid Substrates with Sub-micrometer Resolution (Adv. Mater. 15/2006)

      C. J. Campbell, S. K. Smoukov, K. J. M. Bishop, E. Baker and B. A. Grzybowski

      Article first published online: 27 JUL 2006 | DOI: 10.1002/adma.200690062

      Micropatterned hydrogel stamps carrying etchant solutions are used to microstructure glass and silicon with complex 3D architectures (see figure and inside cover). A two-way reaction–diffusion mechanism initiated from the stamp enables direct printing of entire microdevices (left to right: two-level microfluidic channels, curvilinear microlenses in glass, nanostructured silicon) into solid substrates with resolution down to 300 nm.

  3. Contents

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Reviews
    6. Communications
    7. Research News
    8. Index
    1. Contents: Adv. Mater. 15/2006 (pages 1931–1939)

      Article first published online: 27 JUL 2006 | DOI: 10.1002/adma.200690059

  4. Reviews

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Reviews
    6. Communications
    7. Research News
    8. Index
    1. Negative-Index Materials: New Frontiers in Optics (pages 1941–1952)

      C. M. Soukoulis, M. Kafesaki and E. N. Economou

      Article first published online: 11 JUL 2006 | DOI: 10.1002/adma.200600106

      Thumbnail image of graphical abstract

      Negative refractive index materials demonstrate unique properties determined not by the fundamental physical properties of their constituents, but rather by the shape and distribution of the specific patterns included in them. The figure shows an electromagnetic wave being focused as it passes through a planar negative refactive index slab. This Review describes the current experimental and theoretical developments in the field of these unique materials.

    2. Quantum Dots in Biological and Biomedical Research: Recent Progress and Present Challenges (pages 1953–1964)

      J. M. Klostranec and W. C. W. Chan

      Article first published online: 27 JUL 2006 | DOI: 10.1002/adma.200500786

      Thumbnail image of graphical abstract

      The emergence of semiconductor quantum dots for biomedical research is described in this Review. A brief history of the field is provided, together with a basic description of the synthesis and photophysical properties (see figure) of quantum dots and examples of their applications in biomedical research. Furthermore, the current limitations and hurdles as well as the future outlook of the field are summarized.

  5. Communications

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Reviews
    6. Communications
    7. Research News
    8. Index
    1. Fabrication of Stable Low-Density Silica Aerogels Containing Luminescent ZnS Capped CdSe Quantum Dots (pages 1965–1967)

      L. Sorensen, G. F. Strouse and A. E. Stiegman

      Article first published online: 27 JUL 2006 | DOI: 10.1002/adma.200600791

      Thumbnail image of graphical abstract

      Luminescent CdSe quantum dots of 2.5 and 6.0 nm dimension have been incorporated into a low-density silica aerogels matrix. The aerogels are formed from the supercritical CO2 extraction of an alcogel containing quantum dots surface passivated with 3-aminopropyltriethoxysilane. The resulting aerogels (see figure and cover) are low scattering and show intense, stable luminescence.

    2. Magnetically Motive Porous Sphere Composite and Its Excellent Properties for the Removal of Pollutants in Water by Adsorption and Desorption Cycles (pages 1968–1971)

      Z. H. Sun, L. F. Wang, P. P. Liu, S. C. Wang, B. Sun, D. Z. Jiang and F.-S. Xiao

      Article first published online: 27 JUL 2006 | DOI: 10.1002/adma.200600337

      Thumbnail image of graphical abstract

      A unique, facile, and controllable route for the synthesis of magnetically motive porous sphere composites consisting of iron carbide, iron, and graphite is reported. The composites have a high surface area, large spheres, hierarchical micropores and macropores, good magnetic separability (see figure), and suitable hydrophobic and oleophilic properties. Pollutants can be almost completely adsorbed onto the composite and re-released in ethanol.

    3. Particle Surface Design using an All-Dry Encapsulation Method (pages 1972–1977)

      K. K. S. Lau and K. K. Gleason

      Article first published online: 10 JUL 2006 | DOI: 10.1002/adma.200600896

      Thumbnail image of graphical abstract

      Initiated chemical vapor deposition enables an all-dry encapsulation of fine particles down to the nanoscale by functional polymers. Initiator vapor is first thermally activated to form primary radicals, which, together with the monomer vapor, are adsorbed onto the particle surface where free-radical polymerization creates a stoichiometric polymer coating (see figure). This polymer coating can subsequently be immobilized with other desired functional molecules.

    4. Growth of CdSe Quantum Rods and Multipods Seeded by Noble-Metal Nanoparticles (pages 1978–1982)

      K.-T. Yong, Y. Sahoo, M. T. Swihart and P. N. Prasad

      Article first published online: 10 JUL 2006 | DOI: 10.1002/adma.200600368

      Thumbnail image of graphical abstract

      CdSe quantum rods are prepared at much milder conditions than previously reported, using noble-metal seed particles to initiate growth. The CdSe nanocrystals initially form as multipods that cleave to yield freestanding quantum rods (see figure) with high photoluminescence quantum yields. This study provides a new direction in developing facile syntheses of semiconductor NCs with nonspherical morphology, thereby making available new building blocks for nanotechnology.

    5. Reversible Nanometer-Scale Data Storage on a Self-Assembled, Organic, Crystalline Thin Film (pages 1983–1987)

      Y. Q. Wen, J. X. Wang, J. P. Hu, L. Jiang, H. J. Gao, Y. L. Song and D. B. Zhu

      Article first published online: 4 JUL 2006 | DOI: 10.1002/adma.200502556

      Thumbnail image of graphical abstract

      An organic donor–acceptor molecule, 4′-cyano-2,6-dimethyl-4-hydroxy azobenzene (CDHAB), has been designed and synthesized for data storage. Reversible nanometer-scale data storage is realized on its highly ordered self-assembled thin film by applying voltage pulses between a scanning tunneling microscope tip and the substrate. The changes in the conductance of the CDHAB film result in the formation of the information dots (see figure).

    6. Biologically Programmed Synthesis of Bimetallic Nanostructures (pages 1988–1992)

      J. M. Slocik and R. R. Naik

      Article first published online: 4 JUL 2006 | DOI: 10.1002/adma.200600327

      Thumbnail image of graphical abstract

      Catalytic bimetallic nanoparticles are synthesized by exploiting the interaction between peptides and inorganic materials to program the peptide sequence such that it can serve as a template in the synthesis of gold nanoparticles as well as direct the binding to Pd ions to the surface of the Au nanoparticles (see figure).

    7. In-Plane Bandgap Engineering by Modulated Hydrogenation of Dilute Nitride Semiconductors (pages 1993–1997)

      M. Felici, A. Polimeni, G. Salviati, L. Lazzarini, N. Armani, F. Masia, M. Capizzi, F. Martelli, M. Lazzarino, G. Bais, M. Piccin, S. Rubini and A. Franciosi

      Article first published online: 10 JUL 2006 | DOI: 10.1002/adma.200600487

      Thumbnail image of graphical abstract

      In-plane bandgap engineering of dilute nitrides by spatially delimited hydrogen irradiation (left, microphotoluminescence image of GaAsN) or displacement (right, cathodoluminescence image of hydrogenated GaAsN) is reported.

    8. Targeting and Uptake of Multilayered Particles to Colorectal Cancer Cells (pages 1998–2003)

      C. Cortez, E. Tomaskovic-Crook, A. P. R. Johnston, B. Radt, S. H. Cody, A. M. Scott, E. C. Nice, J. K. Heath and F. Caruso

      Article first published online: 6 JUL 2006 | DOI: 10.1002/adma.200600564

      Thumbnail image of graphical abstract

      Core/shell particles and capsules formed by a layer-by-layer technique are biofunctionalized with a humanized A33 monoclonal antibody (huA33 mAb) that binds to the A33 antigen present on colorectal cancer cells (see figure). Targeting to a colorectal cancer cell line shows selective binding and internalization of particles.

    9. Direct Printing of 3D and Curvilinear Micrometer-Sized Architectures into Solid Substrates with Sub-micrometer Resolution (pages 2004–2008)

      C. J. Campbell, S. K. Smoukov, K. J. M. Bishop, E. Baker and B. A. Grzybowski

      Article first published online: 4 JUL 2006 | DOI: 10.1002/adma.200600716

      Thumbnail image of graphical abstract

      Micropatterned hydrogel stamps carrying etchant solutions are used to microstructure glass and silicon with complex 3D architectures (see figure and inside cover). A two-way reaction–diffusion mechanism initiated from the stamp enables direct printing of entire microdevices (left to right: two-level microfluidic channels, curvilinear microlenses in glass, nanostructured silicon) into solid substrates with resolution down to 300 nm.

    10. Osmoresponsive Glasses: Osmotically Triggered Volume Changes of Organosilica Sol–Gels as a Means for Controlled Release of Biomolecules (pages 2009–2013)

      B. C. Dave, K. Deshpande, M. S. Gebert and J. C. McAuliffe

      Article first published online: 10 JUL 2006 | DOI: 10.1002/adma.200600852

      Thumbnail image of graphical abstract

      Organosilica sol–gels are shown to exhibit bulk volume changes when the osmolarity of the external medium is altered (see figure). These glasses stabilize enzymes in low-water-content laundry detergent formulations, and when diluted with water, the enzymes can be released on demand for potential applications in fabric care systems. Such osmotic triggering is reminiscent of osmoregulation and osmoadaption in natural biological systems.

    11. A Volume Holographic Sol-Gel Material with Large Enhancement of Dynamic Range by Incorporation of High Refractive Index Species (pages 2014–2017)

      F. del Monte, O. Martínez, J. A. Rodrigo, M. L. Calvo and P. Cheben

      Article first published online: 27 JUL 2006 | DOI: 10.1002/adma.200502675

      Thumbnail image of graphical abstract

      Improved performance of volume holographic sol-gel materials—refractive index modulations in the 10–2 range, diffraction efficiencies near 100 %, and low levels of noise scattering—are reported that arise from the incorporation of Zr-based high refractive index species capable of diffusing from dark to bright fringes of the interference pattern (see figure).

    12. Organic Solar Cells Using Transparent SnO2–F Anodes (pages 2018–2022)

      F. Yang and S. R. Forrest

      Article first published online: 6 JUL 2006 | DOI: 10.1002/adma.200600797

      Thumbnail image of graphical abstract

      Copper phthalocyanine/C60/2,9- dimethyl-4,7-diphenyl-1,10-phenanthroline/Ag heterojunction organic solar cells are grown on low-cost SnO2–F-coated glass using organic vapor-phase deposition (see figure). The bulk heterojunction (BHJ) solar cell with nanoscale CuPc protrusions shows a 2.5 % power-conversion efficiency under 1 sun illumination. The high efficiency in BHJ solar cells is attributed to the increased exciton dissociation efficiency at the CuPc/C60 interface.

    13. Synthesis of WC Nanotubes (pages 2023–2027)

      S. V. Pol, V. G. Pol and A. Gedanken

      Article first published online: 4 JUL 2006 | DOI: 10.1002/adma.200600715

      Thumbnail image of graphical abstract

      A nonaqueous, solvent- and template-free, and straightforward route is described for the synthesis of inorganic WC nanotubes (see figure). The thermal decomposition of W(CO)6 in the presence of Mg powder is carried out at 900 °C under the autogenic pressure of the precursors in a closed Swagelok reactor to yield WC nanotubes for the first time. The reaction mechanism is supported by experimental data.

    14. Inter-Nanoparticle Bonds in Agglomerates Studied by Nanoindentation (pages 2028–2030)

      Y. Raichman, M. Kazakevich, E. Rabkin and Y. Tsur

      Article first published online: 4 JUL 2006 | DOI: 10.1002/adma.200600538

      Thumbnail image of graphical abstract

      A new approach for the measurement of mechanical properties of nanoparticle aggregates is presented. Individual agglomerates are fixed onto a hard substrate and their strength is measured by nanoindentation. Images acquired using the nanoindenter itself (see figure) before and after the indentation show directly the imprints of the nanoindenter tip. It is proposed that the agglomerate strength can be correlated with the shape of the nanoindentation load-displacement curves.

    15. Liquid–Solid–Solution Synthesis of Biomedical Hydroxyapatite Nanorods (pages 2031–2034)

      X. Wang, J. Zhuang, Q. Peng and Y. D. Li

      Article first published online: 10 JUL 2006 | DOI: 10.1002/adma.200600033

      Thumbnail image of graphical abstract

      Uniform hydroxyapatite nanorods with controllable sizes, aspect ratios (from 8–10 to above 100:1), and surface properties (hydrophobic or hydrophilic) have been successfully prepared by systematically tuning the interfaces between surfactants and the central atoms of hydroxyapatite using liquid–solid–solution synthesis. Hydroxyapatite nanorods like those shown in the figure may be useful in the development of organic–inorganic artificial bone.

    16. A Double INHIBIT Logic Gate Employing Configuration and Fluorescence Changes (pages 2035–2038)

      D.-H. Qu, F.-Y. Ji, Q.-C. Wang and H. Tian

      Article first published online: 6 JUL 2006 | DOI: 10.1002/adma.200600235

      Thumbnail image of graphical abstract

      A lockable as well as double INHIBIT logic gate based on a [2]rotaxane employing configuration and fluorescence changes has been demonstrated (see figure). Importantly, the output “0” and “1” states of the current logic circuits represent several different supramolecular configurations. The photoisomerization process is completely reversible, making the shuttling motions of the cyclodextrin ring repeatable and accompanied by a reversible florescence signal.

    17. Magnus' Green Salt Revisited: Impact of Platinum–Platinum Interactions on Electronic Structure and Carrier Mobilities (pages 2039–2043)

      E.-G. Kim, K. Schmidt, W. R. Caseri, T. Kreouzis, N. Stingelin-Stutzmann and J.-L. Brédas

      Article first published online: 6 JUL 2006 | DOI: 10.1002/adma.200600252

      Thumbnail image of graphical abstract

      Magnus' green salt is the prototype of a class of organic–inorganic hybrid semiconducting materials that combine attractive charge-transport properties and processability. By using density-functional-theory methods, the electronic structure of Magnus' green salt is investigated, in particular the nature of the interplatinum interactions (see figure). In conjunction with time-of-flight measurements of the carrier mobilities, key structure–property relationships for these materials are re-established.

    18. Design of Self-Assembled Multiferroic Nanostructures in Epitaxial Films (pages 2044–2047)

      I. Levin, J. Li, J. Slutsker and A. L. Roytburd

      Article first published online: 10 JUL 2006 | DOI: 10.1002/adma.200600288

      Thumbnail image of graphical abstract

      Self-assembled multiferroic nanostructures with controllable morphologies are obtained by varying the stress state in epitaxial composite films containing ferrimagnetic CoFe2O4 and ferroelectric PbTiO3. The stress state can be controlled by using different substrate orientations and phase fractions. The figure shows the transition from CoFe2O4 magnetic nanorods embedded in a ferroelectric PbTiO3 matrix (a) to PbTiO3 ferroelectric nanorods in a CoFe2O4 matrix (b).

    19. Nanostructured Organic Material: From Molecular Chains to Organic Nanodots (pages 2048–2052)

      J. Méndez, R. Caillard, G. Otero, N. Nicoara and J. A. Martín-Gago

      Article first published online: 27 JUL 2006 | DOI: 10.1002/adma.200502115

      Thumbnail image of graphical abstract

      Deposition of 3,4,9,10-perylene-tetracarboxylic-dianhydride on iron island arrays on Au(111) results in the formation of new nanostructures. By controlling the amount of iron deposited on the gold surface, two kinds of aggregates are obtained: molecular chains and organic nanodots (see figure). These nanostructures possess a different density of states from the two-dimensional self-assembled molecular layer.

  6. Research News

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Reviews
    6. Communications
    7. Research News
    8. Index
    1. The Microemulsion Synthesis of Hydrophobic and Hydrophilic Silicon Nanocrystals (pages 2053–2056)

      R. D. Tilley and K. Yamamoto

      Article first published online: 27 JUL 2006 | DOI: 10.1002/adma.200600118

      Thumbnail image of graphical abstract

      A simple method for producing uniformly sized nanometer-scale silicon nanocrystals in inverse micelles with powerful hydride reducing agents is reviewed. The small, monodisperse nanocrystals produce a sharp blue photoluminescence (see figure) resulting from direct bandgap emission. The surface properties of the silicon nanocrystals can be controlled to produce hydrophobic or hydrophilic particles, with an example application in biological imaging presented.

  7. Index

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Reviews
    6. Communications
    7. Research News
    8. Index
    1. Author Index and Subject Index Adv. Mater. 15/2006 (pages 2057–2058)

      Article first published online: 27 JUL 2006 | DOI: 10.1002/adma.200690060

SEARCH

SEARCH BY CITATION