Advanced Materials

Cover image for Vol. 19 Issue 9

May, 2007

Volume 19, Issue 9

Pages 1155–1292

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Review
    6. Communications
    7. Index
    1. Cover Picture: UV-Light-Induced Swelling and Visible-Light-Induced Shrinking of a TiO2-Containing Redox Gel (Adv. Mater. 9/2007)

      T. Tatsuma, K. Takada and T. Miyazaki

      Article first published online: 27 APR 2007 | DOI: 10.1002/adma.200790032

      A poly(acrylate) gel containing Ag+and TiO2nanoparticles is swollen by UV light and shrunk by visible light in water (see figure and cover). The swollen gel keeps its size and shape in the dark. Localized irradiation with UV and visible light causes localized swelling and shrinking, respectively.

  2. Inside Front Cover

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Review
    6. Communications
    7. Index
    1. Inside Front Cover: Anti-Lotus Effect for Nanostructuring at the Leidenfrost Temperature (Adv. Mater. 9/2007)

      M. Elbahri, D. Paretkar, K. Hirmas, S. Jebril and R. Adelung

      Article first published online: 27 APR 2007 | DOI: 10.1002/adma.200790033

      Nanostructuring at the Leidenfrost temperature is carried out by exposing water-based solution droplets to overheated substrates at temperatures above 200 °C. This method is able to produce nanowires that form different geometries (see figure and inside cover) by inverting the Lotus effect: instead of removing material, moving droplets deposit nanoparticles. Alignment is achieved by employing simple masks.

  3. Contents

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Review
    6. Communications
    7. Index
    1. Contents: Adv. Mater. 9/2007 (pages 1155–1163)

      Article first published online: 27 APR 2007 | DOI: 10.1002/adma.200790030

  4. Review

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Review
    6. Communications
    7. Index
    1. Beyond Silica: Nonoxidic Mesostructured Materials (pages 1165–1181)

      M. G. Kanatzidis

      Article first published online: 13 APR 2007 | DOI: 10.1002/adma.200601763

      Thumbnail image of graphical abstract

      Mesostructured nonoxidic solids allow new functionalities that are difficult to achieve/unavailable in oxidic frameworks—the illustration shows how these materials can be used to construct the “negative image” of a quantum dot array. Advances in experimental methodologies allow facile synthesis of these materials for further research, and this Review focuses on design and synthesis of mesostructured/mesoporous nonoxidic materials.

  5. Communications

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Review
    6. Communications
    7. Index
    1. Understanding the Deformation and Fracture of Nitinol Endovascular Stents Using In Situ Synchrotron X-Ray Microdiffraction (pages 1183–1186)

      A. Mehta, X.-Y. Gong, V. Imbeni, A. R. Pelton and R. O. Ritchie

      Article first published online: 13 APR 2007 | DOI: 10.1002/adma.200601916

      Thumbnail image of graphical abstract

      Endovascular stents manufactured from superelastic Nitinol represent a major component in the fight against heart disease. However, accurate characterization of the stress/strain distributions, which govern the deformation and fracture behavior in such stents, is essential for their prolonged safe use in human arteries. Here we report the first direct synchrotron X-ray microdiffraction measurements of the local strain field (see figure) of a stent-like Nitinol component subjected to realistic multiaxial loading.

    2. Bottom-Up Fabrication of Photonic Defect Structures in Cholesteric Liquid Crystals Based on Laser-Assisted Modification of the Helix (pages 1187–1190)

      H. Yoshida, C. H. Lee, Y. Matsuhisa, A. Fujii and M. Ozaki

      Article first published online: 13 APR 2007 | DOI: 10.1002/adma.200601753

      Thumbnail image of graphical abstract

      Controlled fabrication of defect structures is performed in cholesteric liquid crystals by a laser-assisted polymerization process that induces a local elongation of the helix (see figure). Low-threshold laser action is observed from the photonic defect-mode observed within the selective reflection band.

    3. A Highly Ordered Material from Magnetically Aligned Peptide Amphiphile Nanofiber Assemblies (pages 1191–1195)

      D. W. P. M. Löwik, I. O. Shklyarevskiy, L. Ruizendaal, P. C. M. Christianen, J. C. Maan and J. C. M. van Hest

      Article first published online: 13 APR 2007 | DOI: 10.1002/adma.200602295

      Thumbnail image of graphical abstract

      Oriented peptide amphiphile-based nanoribbons with a crystal-like molecular order are prepared by application of a strong magnetic field. The (supra)molecular order is transferred on a polymer backbone formed within the assemblies, which is reflected in the highly anisotropic optical properties of the material, as shown in the figure.

    4. Microscopic Understanding of the Anisotropic Conductivity of PEDOT:PSS Thin Films (pages 1196–1200)

      A. M. Nardes, M. Kemerink, R. A. J. Janssen, J. A. M. Bastiaansen, N. M. M. Kiggen, B. M. W. Langeveld, A. J. J. M. van Breemen and M. M. de Kok

      Article first published online: 13 APR 2007 | DOI: 10.1002/adma.200602575

      Thumbnail image of graphical abstract

      The anisotropic conductivity of thin films of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is correlated to the film morphology as obtained from scanning tunneling and atomic force microscopy images. The material was found to consist of layers of flattened PEDOT-rich particles that are separated by quasi-continuous PSS lamella (see figure).

    5. Preparation and Behavior of Brownish, Clear Nanodiamond Colloids (pages 1201–1206)

      M. Ozawa, M. Inaguma, M. Takahashi, F. Kataoka, A. Krüger and E. Ōsawa

      Article first published online: 13 APR 2007 | DOI: 10.1002/adma.200601452

      Thumbnail image of graphical abstract

      A new facile method that employs high-power sonication is used to break up firmly agglutinated nanodiamonds and obtain dispersion just as effectively as stirred-media milling. The dispersion properties of the de-agglutinated nanodiamonds in various nonaqueous solvents, and the pH-dependent dispersion/precipitation behavior of the hydrosols are presented (see figure). The brownish color of the colloids is attributed mostly to the Rayleigh scattering superimposed over the finite absorption in the visible wavelength.

    6. Chirality Induction in Bulk Gold and Silver (pages 1207–1211)

      H. Behar-Levy, O. Neumann, R. Naaman and D. Avnir

      Article first published online: 13 APR 2007 | DOI: 10.1002/adma.200601702

      Thumbnail image of graphical abstract

      Can a metal be made chiral? Evidence is provided for the induction of chirality in metals doped with chiral molecules (see figure). Gold and silver doped with L-glutathione or L-quinine or either D- or L-tryptophan show clear differences in the emission efficiency of the metal photoelectrons when irradiated with either clockwise or counter-clockwise circularly polarized UV light.

    7. Forming Highly Ordered Arrays of Functionalized Polymer Nanowires by Dewetting on Micropillars (pages 1212–1217)

      J. Guan, B. Yu and L. J. Lee

      Article first published online: 4 APR 2007 | DOI: 10.1002/adma.200602466

      Thumbnail image of graphical abstract

      1D nanostructures are of great interest for numerous applications: a simple and low-cost process to generate large arrays of polymer nanowires by dewetting aqueous polymer solution on an array of micropillars is developed. These nanowires are typically less than 10 nm in lateral size and can be functionalized by incorporation of molecules or nanoparticles such as quantum dots (see figure).

    8. Direct 3D Patterning of TiO2 Using Femtosecond Laser Pulses (pages 1218–1221)

      S. Passinger, M. S. M. Saifullah, C. Reinhardt, K. R. V. Subramanian, B. N. Chichkov and M. E. Welland

      Article first published online: 13 APR 2007 | DOI: 10.1002/adma.200602264

      Thumbnail image of graphical abstract

      Direct 3D patterning of TiO2 with femtosecond laser pulses using a sol–gel-based negative-tone spin-coatable TiO2 resist is demonstrated (see figure). A layer of the resist was spun on glass and patterned in three dimensions by exposing it to femtosecond laser pulses and then developing in acetone. Heat treatment at 400 °C in air gave 3D patterns that were ca. 50 % of their original size.

    9. High-Throughput and Etch-Selective Nanoimprinting and Stamping Based on Fast- Thermal-Curing Poly(dimethylsiloxane)s (pages 1222–1227)

      C. Pina-Hernandez, J.-S. Kim, L. J. Guo and P.-F. Fu

      Article first published online: 13 APR 2007 | DOI: 10.1002/adma.200601905

      Thumbnail image of graphical abstract

      A thermally curable poly(dimethylsiloxane)-based nanoimprinting resist allows an extremely fast replication (few seconds) of 70 nm line-width structures at moderate temperatures and low pressures (see figure). The high silicon content of this material also makes it highly resistant to reactive-ion etching, allowing the imprinted pattern to be transferred into SiO2 without any additional hard etching mask. The imprinted structure can be used as a stamp directly.

    10. Tensile Mechanics of Electrospun Multiwalled Nanotube/Poly(methyl methacrylate) Nanofibers (pages 1228–1233)

      L.-Q. Liu, D. Tasis, M. Prato and H. D. Wagner

      Article first published online: 13 APR 2007 | DOI: 10.1002/adma.200602226

      Thumbnail image of graphical abstract

      Carbon-nanotube-reinforced, single electrospun PMMA nanofibers (see figure) exhibit an improved Young's modulus and tensile strength relative to unreinforced PMMA nanofibers. The Young's modulus data fits well with the theoretical prediction of the Halpin–Tsai equation. The tensile strength data shows a relatively large variability, which can adequately be fitted by Poisson–Weibull statistics.

    11. Synthesis and Characterization of Regioregular and Regiorandom Unsymmetrically Substituted Poly(2,5-dialkoxy-1,4-phenylene ethynylene)s (pages 1234–1238)

      R. R. Nambiar, G. L. Brizius and D. M. Collard

      Article first published online: 4 APR 2007 | DOI: 10.1002/adma.200602902

      Thumbnail image of graphical abstract

      Regioregular and regiorandom analogues of a dialkoxy-substituted poly(1,4-phenylene ethynylene) (PPE) bearing a pair of dissimilar side chains (dodecyloxy and methoxy) on each ring have been prepared to explore how the relative placement of substituents (see figure) can be used to modify the properties of this class of conjugated polymers. A preliminary study of the effect of regioregularity on properties is presented in which regiorandom and regioregular polymers are compared.

    12. Electrophoresis Coating of Titanium Dioxide on Aligned Carbon Nanotubes for Controlled Syntheses of Photoelectronic Nanomaterials (pages 1239–1243)

      Y. Yang, L. Qu, L. Dai, T.-S. Kang and M. Durstock

      Article first published online: 5 APR 2007 | DOI: 10.1002/adma.200602181

      Thumbnail image of graphical abstract

      Using electrophoresis for TiO2coating and photoexcited electrons for metal-nanoparticle deposition, a facile method for the development of aligned coaxial nanowires of carbon nanotubes sheathed with TiO2 (see figure), and well-defined TiO2 nanomembranes decorated with and without metal nanoparticles, is developed. The TiO2-based nanostructures show fast photocurrent responses and possess unique photoinduced electron-transfer properties.

    13. Carbon-Nanotube Biofibers (pages 1244–1248)

      C. Lynam, S. E. Moulton and G. G. Wallace

      Article first published online: 5 APR 2007 | DOI: 10.1002/adma.200601986

      Thumbnail image of graphical abstract

      A procedure wherein biomolecules are used as both dispersant and coagulant for carbon nanotubes (CNTs) to enable wet-spinning of fibers is developed (see figure). These fibers have good mechanical strength (tensile strengths up to 170 MPa) and the highest electrical conductivity (as high as 130 S cm–1) for as-produced polymer-containing CNT fibers hitherto reported.

    14. UV-Light-Induced Swelling and Visible-Light-Induced Shrinking of a TiO2-Containing Redox Gel (pages 1249–1251)

      T. Tatsuma, K. Takada and T. Miyazaki

      Article first published online: 13 APR 2007 | DOI: 10.1002/adma.200602386

      Thumbnail image of graphical abstract

      A poly(acrylate) gel containing Ag+and TiO2nanoparticles is swollen by UV light and shrunk by visible light in water (see figure and cover). The swollen gel keeps its size and shape in the dark. Localized irradiation with UV and visible light causes localized swelling and shrinking, respectively.

    15. Enzyme-Responsive Polymer Hydrogel Particles for Controlled Release (pages 1252–1256)

      P. D. Thornton, R. J. Mart and R. V. Ulijn

      Article first published online: 13 APR 2007 | DOI: 10.1002/adma.200601784

      Thumbnail image of graphical abstract

      A conceptually new approach to polymer-based enzyme-triggered release is described, whereby the selective catalytic action of (disease-specific) enzymes triggers a charge-induced swelling response in chemically crosslinked hydrogel particles, resulting in the release of physically entrapped macromolecules (see figure).

    16. High-Strength and Multifunctional Macroscopic Fabric of Single-Walled Carbon Nanotubes (pages 1257–1261)

      S. Wang, Z. Liang, B. Wang and C. Zhang

      Article first published online: 13 APR 2007 | DOI: 10.1002/adma.200602140

      Thumbnail image of graphical abstract

      More than a sixfold increase in tensile strength and modulus of the macroscopic SWNT membranes is demonstrated (see figure) using electron-beam irradiation to effectively form intertube crosslinks. The strength increase is a quadratic function of irradiation dose.

    17. Anti-Lotus Effect for Nanostructuring at the Leidenfrost Temperature (pages 1262–1266)

      M. Elbahri, D. Paretkar, K. Hirmas, S. Jebril and R. Adelung

      Article first published online: 13 APR 2007 | DOI: 10.1002/adma.200601694

      Thumbnail image of graphical abstract

      Nanostructuring at the Leidenfrost temperature is carried out by exposing water-based solution droplets to overheated substrates at temperatures above 200 °C. This method is able to produce nanowires that form different geometries (see figure and inside cover) by inverting the Lotus effect: instead of removing material, moving droplets deposit nanoparticles. Alignment is achieved by employing simple masks.

    18. Template- and Vacuum-Ultraviolet- Assisted Fabrication of a Ag-Nanoparticle Array on Flexible and Rigid Substrates (pages 1267–1271)

      J. Li, K. Kamata, S. Watanabe and T. Iyoda

      Article first published online: 13 APR 2007 | DOI: 10.1002/adma.200602851

      Thumbnail image of graphical abstract

      A versatile, vacuum-ultraviolet-assisted macroscopic fabrication of hexagonally arranged Ag-nanoparticle arrays with controlled periodicity by using phase-segregated amphiphilic diblock copolymer films as templates is demonstrated on either flexible or rigid substrates. After Ag+ is selectively incorporated into the formed hydrophilic nanocylinders, both the photoreduction of Ag+ and a concomitant etching of the copolymer template are achieved by applying a 172 nm photon source (see figure).

    19. Simple Fabrication Method of Conductive Polymeric Arrays by Using Direct Laser Interference Micro-/Nanopatterning (pages 1272–1275)

      D. A. Acevedo, A. F. Lasagni, C. A. Barbero and F. Mücklich

      Article first published online: 4 APR 2007 | DOI: 10.1002/adma.200601693

      Thumbnail image of graphical abstract

      Thin films of polyaniline (PANI) deposited onto different polymeric substrates are nanostructured by using “direct laser interference patterning” at room temperature and pressure in air atmosphere. Regular linelike arrays (see figure) with thicknesses up to 600 nm are fabricated and their activity is determined using different techniques. The structuring mechanisms of PANI supported in both polycarbonate and polyimide films are demonstrated using cross-sectional analyses performed with a dual-beam workstation.

    20. Reversible Photoinduced Shape Changes of Crystalline Organic Nanorods (pages 1276–1280)

      R. O. Al-Kaysi and C. J. Bardeen

      Article first published online: 4 APR 2007 | DOI: 10.1002/adma.200602741

      Thumbnail image of graphical abstract

      Crystalline nanorods composed of 9-anthracene carboxylic acid (9-AC) are synthesized using nanoporous Al2O3 templates. When a segment of an isolated rod is exposed to UV-light, localized solid-state photodimerization of the 9-AC molecules induces micrometer-scale bending (see figure). The nanorod reverts back to its original shape after several minutes in the dark at room temperature. The reversible photoinduced shape change could be repeated multiple times.

    21. High-Efficiency Blue Light-Emitting Diodes Based on a Polyphenylphenyl Compound with Strong Electron-Accepting Groups (pages 1281–1285)

      X. J. Xu, S. Y. Chen, G. Yu, C. A. Di, H. You, D. G. Ma and Y. Q. Liu

      Article first published online: 4 APR 2007 | DOI: 10.1002/adma.200601919

      Thumbnail image of graphical abstract

      The synthesis and characterization of two new polyphenylphenyl compounds is reported. One compound (CPP) acts as a blue light-emitting material, but contains strong electron-accepting groups that form exciplexes with electron-donating arylamines that are widely used as hole-transporting materials. Inserting a layer of the other compound into the organic light-emitting diodes (see figure) suppresses the formation of exciplexes, and gives high-efficiency blue-light emission from the CPP layer.

    22. Chain-Scission-Induced Intercalation as a Facile Route to Polymer Nanocomposites (pages 1286–1290)

      D. J. Frankowski, S. A. Khan and R. J. Spontak

      Article first published online: 15 MAR 2007 | DOI: 10.1002/adma.200600793

      Thumbnail image of graphical abstract

      Immiscible polystyrene (PS)/clay nanocomposites undergo intercalation upon spatially tuned and atmosphere-regulated thermal-oxidative chain scission (see figure), with resultant increases in moduli and thermal stability. Shortened PS chains generated by scission predominantly locate in the clay galleries and not in the bulk where they would detrimentally affect mechanical properties.

  6. Index

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Review
    6. Communications
    7. Index
    1. Author Index and Subject Index Adv. Mater. 9/2007 (pages 1291–1292)

      Article first published online: 27 APR 2007 | DOI: 10.1002/adma.200790031

SEARCH

SEARCH BY CITATION