Advanced Materials

Cover image for Vol. 19 Issue 7

April, 2007

Volume 19, Issue 7

Pages 899–1010

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Correction
    5. Communications
    6. Book Review
    7. Index
    1. Cover Picture: Length-Dependent Uptake of DNA-Wrapped Single-Walled Carbon Nanotubes (Adv. Mater. 7/2007)

      M. L. Becker, J. A. Fagan, N. D. Gallant, B. J. Bauer, V. Bajpai, E. K. Hobbie, S. H. Lacerda, K. B. Migler and J. P. Jakupciak

      Article first published online: 29 MAR 2007 | DOI: 10.1002/adma.200790026

      A length threshold for cell uptake of DNA-wrapped single-walled carbon nanotubes (SWNTs) by human lung fibroblasts (IMR90) is identified. Competitive uptake experiments with well-defined and characterized length fractions show that SWNTs above the length threshold are excluded from the cell, whereas SWNTs labeled with Cy3-derivatized DNA below the threshold are able to access the cell interior, as shown in the fluorescence image and on the cover.

  2. Contents

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Correction
    5. Communications
    6. Book Review
    7. Index
    1. Contents: Adv. Mater. 7/2007 (pages 899–907)

      Article first published online: 29 MAR 2007 | DOI: 10.1002/adma.200790024

  3. Correction

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Correction
    5. Communications
    6. Book Review
    7. Index
    1. You have free access to this content
      Biomedical Applications of Layer-by-Layer Assembly: From Biomimetics to Tissue Engineering (page 906)

      Z. Tang, Y. Wang, P. Podsiadlo and N. A. Kotov

      Article first published online: 29 MAR 2007 | DOI: 10.1002/adma.200790025

      This article corrects:

      Biomedical Applications of Layer-by-Layer Assembly: From Biomimetics to Tissue Engineering

      Vol. 18, Issue 24, 3203–3224, Article first published online: 16 NOV 2006

  4. Communications

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Correction
    5. Communications
    6. Book Review
    7. Index
    1. A Large, Freestanding, 20 nm Thick Nanomembrane Based on an Epoxy Resin (pages 909–912)

      H. Watanabe and T. Kunitake

      Article first published online: 2 MAR 2007 | DOI: 10.1002/adma.200601630

      Thumbnail image of graphical abstract

      An epoxy resin is prepared as a robust, flexible, freestanding nanomembrane, with thicknesses as small as 20 nm, and perpendicular dimensions of a few centimeters (see figure, width of membrane 2 cm). The existence of a densely crosslinked structure within an ultrathin matrix is the key element for the strength of the nanomembrane. The membrane thicknesses discussed here are approaching the size of large molecules and molecular assembly units.

    2. Micropatterning of Proteins on 3D Porous Polymer Film Fabricated by Using the Breath-Figure Method (pages 913–916)

      Y. Zhang and C. Wang

      Article first published online: 2 MAR 2007 | DOI: 10.1002/adma.200601169

      Thumbnail image of graphical abstract

      A porous polystyrene (PS) film with a well-ordered pore structure (see figure) prepared by using the breath-figure method is used as a template to pattern proteins. Amino-terminated PS is used to produce an amino-terminated surface on the pores in the film and fluorescein-isothiocyanate-conjugated bovine serum albumin is attached to the surface through crosslinking of glutaraldehyde. This is a nonlithographic method for 3D protein micropatterning.

    3. Synthesis of Vertical High-Density Epitaxial Si(100) Nanowire Arrays on a Si(100) Substrate Using an Anodic Aluminum Oxide Template (pages 917–920)

      T. Shimizu, T. Xie, J. Nishikawa, S. Shingubara, S. Senz and U. Gösele

      Article first published online: 2 MAR 2007 | DOI: 10.1002/adma.200700153

      Thumbnail image of graphical abstract

      Growth of vertical epitaxial Si(100) nanowires on Si(100) substrates is demonstrated (see figure) using a combination of an anodic aluminum oxide template, catalytic Au particles embedded in nanopores directly on the Si substrate by using electroless deposition, and vapor–liquid–solid growth using SiH4. HF acid treatment of the porous alumina template is important to realize a direct contact between deposited Au in the AAO nanopores and the Si substrate.

    4. Nano- to Microscale Porous Silicon as a Cell Interface for Bone-Tissue Engineering (pages 921–924)

      W. Sun, J. E. Puzas, T.-J. Sheu, X. Liu and P. M. Fauchet

      Article first published online: 6 MAR 2007 | DOI: 10.1002/adma.200600319

      Thumbnail image of graphical abstract

      Porous Si (PSi) is shown to support and promote primary osteoblast growth (shown in the figure), protein-matrix synthesis, and mineralization. It is also shown that the osteoconductivity of PSi and other cellular responses can be controlled by altering the micro-/ nanoarchitecture of the porous interface. This material has the potential to be a functional biomaterial with both osteoconductivity and drug- delivery functions.

    5. New Magnetic Properties of Silicon/Silicon Oxide Interfaces (pages 925–928)

      G. Kopnov, Z. Vager and R. Naaman

      Article first published online: 6 MAR 2007 | DOI: 10.1002/adma.200601762

      Thumbnail image of graphical abstract

      Silicon/silicon oxide interfaces are found to possess magnetic properties when the surface is etched to a specific morphology. By measuring the surface roughness (see figure) using atomic force microscopy, and monitoring the magnetic response as a function of magnetic field, the relation between the magnetism and the surface structure is established. The observations indicate that the magnetism is related to a cooperative effect on the surface.

    6. Water-Redispersible Isolated Single-Walled Carbon Nanotubes Fabricated by In Situ Polymerization of Micelles (pages 929–933)

      T.-H. Kim, C. Doe, S. R. Kline and S.-M. Choi

      Article first published online: 12 MAR 2007 | DOI: 10.1002/adma.200601991

      Thumbnail image of graphical abstract

      Individually isolated single-walled carbon nanotubes (SWNTs) are coated with a monolayer of cationic surfactant to improve the stability of their dispersions in water. After polymerizing the counterions of the surfactant, the monolayer coating is “locked in” (see figure), and the SWNTs are redispersible even after harsh processing such as freeze-drying, offering improved potential for practical applications.

    7. Donor–Acceptor Nanoensembles Based on Boron Nitride Nanotubes (pages 934–938)

      Q. Huang, A. S. D. Sandanayaka, Y. Bando, C. Y. Zhi, R. Z. Ma, G. Z. Shen, D. Golberg, J. C. Zhao, Y. Araki, O. Ito and L. Gao

      Article first published online: 29 MAR 2007 | DOI: 10.1002/adma.200602058

      Thumbnail image of graphical abstract

      Hybrid materials composed of zinc phthalocyanines (ZnPcs) and BN nanotubes (BNNTs) (see figure) exhibit interesting electronic interactions. The efficient charge separation of these systems is characterized with the aid of an electron mediator, methyl viologen (MV). Photoinduced charge transfer from ZnPc to the BNNTs makes these novel hybrids promising photosensitized charge-separation/electron-mediating systems.

    8. Length-Dependent Uptake of DNA-Wrapped Single-Walled Carbon Nanotubes (pages 939–945)

      M. L. Becker, J. A. Fagan, N. D. Gallant, B. J. Bauer, V. Bajpai, E. K. Hobbie, S. H. Lacerda, K. B. Migler and J. P. Jakupciak

      Article first published online: 20 MAR 2007 | DOI: 10.1002/adma.200602667

      Thumbnail image of graphical abstract

      A length threshold for cell uptake of DNA-wrapped single-walled carbon nanotubes (SWNTs) by human lung fibroblasts (IMR90) is identified. Competitive uptake experiments with well-defined and characterized length fractions show that SWNTs above the length threshold are excluded from the cell, whereas SWNTs labeled with Cy3-derivatized DNA below the threshold are able to access the cell interior, as shown in the fluorescence image and on the cover.

    9. Ultra-High-Aspect-Ratio Titania Nanotubes (pages 946–948)

      C. Richter, Z. Wu, E. Panaitescu, R. J. Willey and L. Menon

      Article first published online: 29 MAR 2007 | DOI: 10.1002/adma.200602389

      Thumbnail image of graphical abstract

      Ultrahigh-aspect-ratio titania nanotubes are fabricated electrochemically in organic-acid-containing chlorine salts. The tubes (see figure) are several tens of micrometers in length and only about 20 nm in diameter. The use of organic acids as anodic electrolyte combined with the vigorous chlorine chemistry result in the incorporation of a significant amount of carbon into the nanotubes. Such high-aspect-ratio nanotubes are shown to have enhanced visible-light-harvesting characteristics.

    10. Fusion of Seashell Nacre and Marine Bioadhesive Analogs: High-Strength Nanocomposite by Layer-by-Layer Assembly of Clay and L-3,4-Dihydroxyphenylalanine Polymer (pages 949–955)

      P. Podsiadlo, Z. Liu, D. Paterson, P. B. Messersmith and N. A. Kotov

      Article first published online: 1 MAR 2007 | DOI: 10.1002/adma.200602706

      Thumbnail image of graphical abstract

      A novel nanostructured composite film (see figure) that takes advantage of two different natural materials—layered nacre and the marine adhesive of mussels—is prepared. L-3,4-Dihydroxyphenylalanine (DOPA) molecules impart unusual adhesive strength to the clay composite and the hardening mechanism found in the natural “cement” plays an equally important role in the strengthening of the “nanostructured nacre”.

    11. Single-Molecule Traffic in Mesoporous Materials: Translational, Orientational, and Spectral Dynamics (pages 956–960)

      C. Jung, C. Hellriegel, J. Michaelis and C. Bräuchle

      Article first published online: 27 FEB 2007 | DOI: 10.1002/adma.200602173

      Thumbnail image of graphical abstract

      The translational and orientational movement of single terrylenediimide dye molecules incorporated as guests in the nanometer-sized pores of an M41S host silica film is observed simultaneously (see figure). By correlating the dynamics of position and orientation as well as orientation and emission spectra of single molecules, the nanoscaled heterogeneities of the mesoporous host are determined.

    12. Synthesis of Carbon Nanofibers and Foam by Catalytic Chemical Vapor Deposition Using a Water-Soluble Alkali Salt Catalyst (pages 961–964)

      Y. Zhang and X. Sun

      Article first published online: 29 MAR 2007 | DOI: 10.1002/adma.200602084

      Thumbnail image of graphical abstract

      By using alkali salts as catalysts during chemical vapor deposition, several nanoscale carbon materials are formed. The morphology of the carbon materials mainly depends on the temperature at which the deposition process is carried out (see figure, width 5 μm, temperature set at 400 °C). The use of water-soluble alkali salts rather than metal catalysts leads to a simple, low-cost, and environmentally friendly approach to the synthesis of these materials.

    13. Universal Gradient Substrates for “Click” Biofunctionalization (pages 965–969)

      N. D. Gallant, K. A. Lavery, E. J. Amis and M. L. Becker

      Article first published online: 29 MAR 2007 | DOI: 10.1002/adma.200602221

      Thumbnail image of graphical abstract

      Versatile templates for gradient immobilization of biomolecules by click chemistry are easily generated from reproducible and tunable surface energy gradients. An arginine–glycine–aspartate (RGD) peptide density gradient controls cell adhesion (see figure), and demonstrates the utility of this fabrication process for making substrates that can screen cell response to bioactive materials.

    14. Nanomechanical Properties of Bioinspired Organic–Inorganic Composite Films (pages 970–974)

      Z. Burghard, A. Tucic, L. P. H. Jeurgens, R. C. Hoffmann, J. Bill and F. Aldinger

      Article first published online: 29 MAR 2007 | DOI: 10.1002/adma.200601068

      Thumbnail image of graphical abstract

      Nacre-like thin films are fabricated via a bioinspired route combining chemical bath deposition of the inorganic component (TiO2) and layer-by-layer alternate adsorption of oppositely charged polyelectrolytes for the organic component (see figure). Nanoindentation testing revealed an increase in hardness and Young's modulus imparted by the alternate-layer architecture of the composite films.

    15. Controlled Termination of the Growth of Vertically Aligned Carbon Nanotube Arrays (pages 975–978)

      K. Liu, K. Jiang, Y. Wei, S. Ge, P. Liu and S. Fan

      Article first published online: 29 MAR 2007 | DOI: 10.1002/adma.200600600

      Thumbnail image of graphical abstract

      Careful control of the termination step during CNT growth results in straight roots and good adhesion to the substrate, in sharp contrast to the roots of naturally terminated CNTs that are highly curved and contain trapped catalyst. Direct force measurements show that well-controlled termination gives rise to an adhesion three times larger than that of natural termination.

    16. A Cleavable-Polycation Template Method for the Fabrication of Noncrosslinked, Porous Polyelectrolyte Multilayered Films (pages 979–983)

      J. Chen, X.-M. Xia, S.-W. Huang and R.-X. Zhuo

      Article first published online: 29 MAR 2007 | DOI: 10.1002/adma.200601588

      Thumbnail image of graphical abstract

      Porous, noncrosslinked polyelectrolyte-complex thin films (see figure), which will find applications in biomedicine, for example for drug or gene delivery, are achieved by using a simple, mild, and efficient method. Layer-by-layer assembly of polyanion and a blend of two polycations is followed by removal of the reductively degradable polycation template in the multilayered film in dithiothreitol solution.

    17. Regioselectively Ordered Silica Nanotubes by Molecular Templating (pages 984–987)

      C. Zollfrank, H. Scheel and P. Greil

      Article first published online: 29 MAR 2007 | DOI: 10.1002/adma.200601548

      Thumbnail image of graphical abstract

      Regioselectively ordered silica nanotubes are formed on molecular polysaccharide derivatives under mild conditions by sol–gel processing using biomimetic principles. The cellulose molecules serve as a rigid backbone, whilst structure-directing oligopropylamino residues are introduced to mimic the functional groups responsible for silica formation by diatoms (see figure). The obtained silica nanotubes exhibit a dual microstructure, consisting of an ordered near-core region and an amorphous mantle.

    18. Monodomain High-Aspect-Ratio 2D and 3D Ordered Porous Alumina Structures with Independently Controlled Pore Spacing and Diameter (pages 988–992)

      R. Krishnan and C. V. Thompson

      Article first published online: 29 MAR 2007 | DOI: 10.1002/adma.200601555

      Thumbnail image of graphical abstract

      Ordered porous alumina with uniform as well as nanofunnel-shaped pore structures are fabricated by using interference lithography to template pore formation and to control the pore spacing, and by using electrolyte changes to independently control and vary the diameters of the pores.

    19. A Tin-Based Amorphous Oxide Composite with a Porous, Spherical, Multideck-Cage Morphology as a Highly Reversible Anode Material for Lithium-Ion Batteries (pages 993–997)

      Y. Yu, C.-H. Chen and Y. Shi

      Article first published online: 12 MAR 2007 | DOI: 10.1002/adma.200601667

      Thumbnail image of graphical abstract

      Thin-film anodes for Li-ion batteries prepared by using electrostatic spray deposition are reported. They consist of a tin-based amorphous oxide composite with a porous, spherical, multideck-cage morphology (see figure). The electrochemical properties of the thin-film electrodes are shown to be improved significantly by introducing Li2O and CuO, the ternary Li2O–CuO–SnO2 electrode being demonstrated to exhibit the best performance.

    20. A Flexible Approach to the Fabrication of Chemical Gradients (pages 998–1000)

      N. Ballav, A. Shaporenko, A. Terfort and M. Zharnikov

      Article first published online: 6 MAR 2007 | DOI: 10.1002/adma.200602168

      Thumbnail image of graphical abstract

      A flexible approach for the fabrication of chemical gradients on different substrates is presented. The key idea of the approach is tuning the exchange reaction between a self-assembled monolayer covering the substrate and a potential molecular substituent by electron irradiation. The figure shows water drops on a hydrophilicity gradient created using this method.

    21. Phosphonic Acid-Modified Barium Titanate Polymer Nanocomposites with High Permittivity and Dielectric Strength (pages 1001–1005)

      P. Kim, S. C. Jones, P. J. Hotchkiss, J. N. Haddock, B. Kippelen, S. R. Marder and J. W. Perry

      Article first published online: 6 MAR 2007 | DOI: 10.1002/adma.200602422

      Thumbnail image of graphical abstract

      Phosphonic acids act as robust surface modifiers on barium titanate (BT) nanoparticles (NPs) (see figure), affording homogeneous, high-volume-fraction composites of such NPs in polymeric hosts by simple solution processing. Pentafluorobenzyl phosphonic acid-modified BT nanocomposite films in poly(vinylidenefluoride-co-hexafluoropropylene) show large relative permittivities and unusually high dielectric breakdown strengths.

  5. Book Review

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Correction
    5. Communications
    6. Book Review
    7. Index
    1. Book Review: Emulsions, Foams, and Suspensions. By Laurier L. Schramm. (page 1008)

      Shlomo Magdassi

      Article first published online: 29 MAR 2007 | DOI: 10.1002/adma.200601431

  6. Index

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Correction
    5. Communications
    6. Book Review
    7. Index
    1. Author Index and Subject Index Adv. Mater. 7/2007 (pages 1009–1010)

      Article first published online: 29 MAR 2007 | DOI: 10.1002/adma.200790023

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