Advanced Materials

Cover image for Vol. 20 Issue 7

April 4, 2008

Volume 20, Issue 7

Pages 1233–1388

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Communications
    6. Communication
    7. Index
    8. Corrections
    1. Cover Picture: Mass-Productions of Vertically Aligned Extremely Long Metallic Micro/Nanowires Using Fiber Drawing Nanomanufacturing (Adv. Mater. 7/2008)

      Xuejun Zhang, Zeyu Ma, Zhong-Yong Yuan and Ming Su

      Version of Record online: 4 APR 2008 | DOI: 10.1002/adma.200890021

      Thumbnail image of graphical abstract

      Vertically aligned ultralong metallic micro/nanowires are fabricated by fiber-drawing nanomanufacturing, where the size reduction is achieved by repeating a simple draw-cut-stack process. This method can control the diameter, length, and interwire spacing over a large range, and provide ordered, nanostructured materials at low-cost for a range of applications, as reported by Ming Su and co-workers on p. 1310.

  2. Inside Front Cover

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Communications
    6. Communication
    7. Index
    8. Corrections
    1. Inside Front Cover: Residual Layer Self-Removal in Imprint Lithography (Adv. Mater. 7/2008)

      Jarrett Dumond and Hong Yee Low

      Version of Record online: 4 APR 2008 | DOI: 10.1002/adma.200890022

      Thumbnail image of graphical abstract

      A new method for imprinting residual-layer-free polymer micro- and nanostructures, particularly 3D structures with overhangs, is demonstrated on p. 1291 by Jared Dumond and Hong Yee Low. This simple and versatile method induces self-removal of the residual layer by its controlled failure along the edges of the imprinted features (AFM image, center). Pristine overhang structures are realized without exposure to plasma or chemical etching agents (SEM image, upper left).

  3. Contents

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Communications
    6. Communication
    7. Index
    8. Corrections
  4. Communications

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Communications
    6. Communication
    7. Index
    8. Corrections
    1. Controlling Combustion Wave Propagation for Transition Metal/Alloy/Cermet Foam Synthesis (pages 1243–1245)

      Peter Erri, Jose Nader and Arvind Varma

      Version of Record online: 25 MAR 2008 | DOI: 10.1002/adma.200701365

      Thumbnail image of graphical abstract

      High-purity nickel, copper, cobalt and alloy foams are synthesized through combustion in an open container (i.e., in air at ambient pressure). This is achieved by varying the fuel/oxidizer ratio during the combustion of a metal nitrate–glycine mixture, a technique previously used for oxide powder formation. By tuning this experimental parameter, reaction propagation is controlled to enable particle agglomeration, leading to foam structures.

    2. Nanoporous Membranes of Hydrogen-bridged Smectic Networks with Nanometer Transverse Pore Dimensions (pages 1246–1252)

      Carmen Luengo Gonzalez, Cees W. M. Bastiaansen, Johan Lub, Joachim Loos, Kanbo Lu, Harry J. Wondergem and Dirk J. Broer

      Version of Record online: 18 MAR 2008 | DOI: 10.1002/adma.200702002

      Thumbnail image of graphical abstract

      Nanoporous membranes are made based on photoreactive hydrogen-bridged smectic liquid crystal dimers. The self-assembled layered structure is locked by photopolymerization. The hydrogen bridges are reversibly opened by heating or by changing the pH. This forms periodic pores of which the integrity is conserved by a covalent crosslinker, setting the spacing at ca. 1 nm. The pores are covered with carboxylic anions that bind to cations or to amines.

    3. Surface-Plasmon-Enhanced Light-Emitting Diodes (pages 1253–1257)

      Min-Ki Kwon, Ja-Yeon Kim, Baek-Hyun Kim, Il-Kyu Park, Chu-Young Cho, Clare Chisu Byeon and Seong-Ju Park

      Version of Record online: 7 MAR 2008 | DOI: 10.1002/adma.200701130

      Thumbnail image of graphical abstract

      A surface-plasmon-enhanced InGaN/GaN multiple quantum well blue LED with an embedded Ag nanoparticle layer inserted between the n-GaN layer and the MQW layer is presented. Time-resolved photoluminescence experiments revealed that the spontaneous emission rate was increased significantly by energy transfer between the quantum well light emitter and the surface plasmons from the Ag nanoparticles. A 32.2% increase in optical output power of the LED is observed.

    4. Ambipolar Charge Transport in DNA Molecules (pages 1258–1262)

      V. A. L. Roy, Ella Lai-Ming Wong, Ben Chi-Bun Ko, Chien-Tu Chao, Siu-Cheong Yan, Beiping Yan, Jong-Ching Wu and Chi-Ming Che

      Version of Record online: 3 APR 2008 | DOI: 10.1002/adma.200701179

      Thumbnail image of graphical abstract

      The electrical transport properties of DNA films in field-effect transistor structure are analyzed. As-depositedfilms did not show electrical conductivity; no DNA network wasobserved between the DNA moleculesbridging the electrodes. When the DNA molecules were stretchedinto a thin film an interpenetratingnetwork formed, and the devicesshowed pronounced field-effects withambipolar behavior. Devices producedby electrostatic trapping of DNA molecules exhibited large bulk parallelcurrents and relatively small field effects.

    5. Biomimetic Foams of High Mechanical Performance Based on Nanostructured Cell Walls Reinforced by Native Cellulose Nanofibrils (pages 1263–1269)

      Anna J. Svagan, My A. S. Azizi Samir and Lars A. Berglund

      Version of Record online: 18 MAR 2008 | DOI: 10.1002/adma.200701215

      Thumbnail image of graphical abstract

      A bioinspired foam in which cellulose nanofibrils are used to reinforce cell walls (ca. 3 µm) is presented. The nanocomposite foams are prepared by a lyophilization technique and show composite structure at the cell-wall scale. The nanocellulosic network shows remarkable mechanical performance, expressed in much-improved modulus and yield strength compared with the neat starch foam.

    6. Transparent, Polycrystalline Upconverting Nanoceramics: Towards 3-D Displays (pages 1270–1273)

      Thomas R. Hinklin, Stephen C. Rand and Richard M. Laine

      Version of Record online: 20 MAR 2008 | DOI: 10.1002/adma.200701235

      Thumbnail image of graphical abstract

      Transparent, polycrystalline (Y0.86-Yb0.11Er0.03)2O3 with an average grain size of 400 nm on irradiation with 980 nm laser light through a mask upconverts the IR photons emitting red light at 662 nm. A model for a red pixel in a 3-D inverted planetarium display is presented (see figure).

    7. Heterogeneous Doping of a Weak Covalent Electrolyte: Proton Conductivity Enhancement of Imidazole by Admixture of Oxide Particles (pages 1274–1278)

      Seniz Beyazyildirim, Klaus Dieter Kreuer, Michael Schuster, Aninda Jiban Bhattacharyya and Joachim Maier

      Version of Record online: 7 MAR 2008 | DOI: 10.1002/adma.200701823

      Thumbnail image of graphical abstract

      The proton conductivity of composites comprising dispersions of various types of nanometer-sized oxide particles in pure imidazole is investigated. The composite materials show significantly enhanced (up to a maximum of ten times in the case of sZrO2) ionic conductivity compared to pure imidazole. The reason is the formation of a space–charge layer on the oxide surface, as a consequence of adsorptive interaction.

    8. Hollow Zinc Oxide Mesocrystals from an Ionic Liquid Precursor (ILP) (pages 1279–1285)

      Zhonghao Li, André Geßner, Jan-Peter Richters, Joachim Kalden, Tobias Voss, Christian Kübel and Andreas Taubert

      Version of Record online: 7 MAR 2008 | DOI: 10.1002/adma.200700935

      Thumbnail image of graphical abstract

      The highly hydrated ionic liquid tetrabutylammonium hydroxide (TBAH) is an efficient ionic liquid precursor (ILP) for the fabrication of zinc oxide mesocrystals. Upon reaction of TBAH with zinc acetate, individual nanometer-sized ZnO building blocks assemble into highly correlated ZnO mesocrystals. The mesocrystals are up to ca. 10 µm in length and the larger crystals have a channel running along the long crystal axis.

    9. High-Performance Organic Field-Effect Transistors with Low-Cost Copper Electrodes (pages 1286–1290)

      Chong-an Di, Gui Yu, Yunqi Liu, Yunlong Guo, Ying Wang, Weiping Wu and Daoben Zhu

      Version of Record online: 3 MAR 2008 | DOI: 10.1002/adma.200701812

      Thumbnail image of graphical abstract

      Top-contact Cu source–drain electrodes are used in high- performance organic field-effect transistors based on pentacene or metal phthalocyanine active layers, as schematically depicted in the figure. Despite the low work function of copper, good hole injection is achieved in these devices because of the formation of an ultrathin CuxO layer at the Cu/organic-semiconductor interface.

    10. Residual Layer Self-Removal in Imprint Lithography (pages 1291–1297)

      Jarrett Dumond and Hong Yee Low

      Version of Record online: 7 MAR 2008 | DOI: 10.1002/adma.200701659

      Thumbnail image of graphical abstract

      A new method for imprinting residual-layer free polymer micro- and nano structures, particularly 3-D structures with overhang, is demonstrated. This simple and versatile method induces self-removal of the residual layer by controlled failure of the patterned film along the edges of the imprinted features. Pristine overhang structures down to ∼500 nm diameter are realized without exposure to plasma or chemical etchants.

    11. Synthesis of Spherical Ultra-High-Surface-Area Monodisperse Amphipathic Polymer Sponges in the Low-Micrometer Size Range (pages 1298–1302)

      Núria Fontanals, Panagiotis Manesiotis, David C. Sherrington and Peter A. G. Cormack

      Version of Record online: 3 MAR 2008 | DOI: 10.1002/adma.200702237

      Thumbnail image of graphical abstract

      Spherical, ultra-high specific surface area monodisperse polymer particles with diameters in the low micrometer size range are disclosed for the first time. The polymer particles are able to sorb significant levels of both hydrocarbon solvents and water, acting in effect as amphipathic micro-sponges. Exciting possibilities for exploitation of the particles in chromatography, diagnostics, sensors, delivery vehicles and catalysis are suggested.

    12. Calix[4]resorcinarene Derivatives as High-Resolution Resist Materials for Supercritical CO2 Processing (pages 1303–1309)

      Nelson M. Felix, Anuja De Silva and Christopher K. Ober

      Version of Record online: 3 MAR 2008 | DOI: 10.1002/adma.200702772

      Thumbnail image of graphical abstract

      Ultra-high-resolution lithography resists based on calix[4] resorcinarene derivatives are shown to be compatible with supercritica l CO2 processing upon the incorporation of specific functionali ties, as illustrated by the inset to the figure. The compounds show high glass-transition temperatures, excellent solubility in supercritical CO2, and good film forming properties, enabling the patterning of line/space features as small as 70 nm (depicted in the figure).

    13. Mass-Productions of Vertically Aligned Extremely Long Metallic Micro/Nanowires Using Fiber Drawing Nanomanufacturing (pages 1310–1314)

      Xuejun Zhang, Zeyu Ma, Zhong-Yong Yuan and Ming Su

      Version of Record online: 7 MAR 2008 | DOI: 10.1002/adma.200702126

      Thumbnail image of graphical abstract

      Vertically aligned metallic micro/nanowires are produced by uniquely combining a novel fiber drawing technique and advanced materials, where the size reduction is achieved by repeating a simple draw-cut-stack process. This method can control the diameter, length and interwire spacing over a large range, and provide ordered materials at low-cost for a range of applications.

    14. High-Temperature Ferromagnetism and Tunable Semiconductivity of (Ba, Sr)M2 ± xRu4 ∓ xO11 (M = Fe, Co): A New Paradigm for Spintronics (pages 1315–1320)

      Larysa Shlyk, Sergiy Kryukov, Barbara Schüpp-Niewa, Rainer Niewa and Lance E. De Long

      Version of Record online: 18 MAR 2008 | DOI: 10.1002/adma.200701951

      Thumbnail image of graphical abstract

      Ternary ruthenium ferrites (Ba,Sr)Fe2 ± xRu4 ∓ xO11 exhibit long-range ferromagnetic order well above room temperature along with favorable narrow- gap semiconducting properties. Electronic structure and physical properties can be tuned by simple chemical substitution of two elements, Fe and Co, or by varying the relative concentration of 3d and 4d elements within the homogeneity range. These promising properties within a single structural family open up a host of potential device applications.

    15. Gate-Controlled Light Emitting Diodes (pages 1321–1324)

      Ebinazar B. Namdas, James S. Swensen, Peter Ledochowitsch, Jonathan D. Yuen, Daniel Moses and Alan J. Heeger

      Version of Record online: 18 MAR 2008 | DOI: 10.1002/adma.200701944

      Thumbnail image of graphical abstract

      The structure and operation of a gate-controlled LED is reported (see figure). The device is properly described as a unipolar organic transistor in series with an OLED. Light emission was visible with brightness exceeding 310 cd m−2 at external quantum efficiency of 0.5%; the brightness is controlled by the gate voltage.

    16. BaPt4Ge12: A Skutterudite Based Entirely on a Ge Framework (pages 1325–1328)

      Ernst Bauer, Andriy Grytsiv, Xing-Qiu Chen, Nataliya Melnychenko-Koblyuk, Gerfried Hilscher, Heinrich Kaldarar, Herwig Michor, Esmaeil Royanian, Martin Rotter, Raimund Podloucky and Peter Rogl

      Version of Record online: 18 MAR 2008 | DOI: 10.1002/adma.200701396

      Thumbnail image of graphical abstract

      A novel superconducting skutterudite is prepared based entirely on a Ge framework incorporating Ba filler atoms. The superconductivity arises from the hybridization of the Ge 4p-like states with Pt 5d-like states and the Ba filler atoms merely serve to stabilize the structure.

    17. Engineering Spontaneous Emission in a Quantum-Dot-Doped Polymer Nanocomposite with Three-Dimensional Photonic Crystals (pages 1329–1332)

      Michael James Ventura and Min Gu

      Version of Record online: 18 MAR 2008 | DOI: 10.1002/adma.200701703

      Thumbnail image of graphical abstract

      The inhibition and enhancement phenomenon of spontaneous emission of PbSe QDs at the second-order stop-gap in a woodpile photonic crystal fabricated by the flexible direct femtosecond laser writing method is investigated. An inhibition of the emission is measured for wavelengths within the stop-gap with a maxima reached at the center of the stop-gap. At the high-energy band edge of the stop-gap, an enhancement of the spontaneous emission is observed.

    18. Polymer-Mediated Mineralization and Self-Similar Mesoscale-Organized Calcium Carbonate with Unusual Superstructures (pages 1333–1338)

      An-Wu Xu, Markus Antonietti, Shu-Hong Yu and Helmut Cölfen

      Version of Record online: 18 MAR 2008 | DOI: 10.1002/adma.200701723

      Thumbnail image of graphical abstract

      The growth of calcium carbonate (calcite) mesocrystals with self similar unique hierarchical superstructures is successfully realized by polymer-controlled crystallization. A mechanism involving the self-organization of smaller inorganic building blocks during the crystallization of calcium carbonate is proposed.

    19. Polybenzimidazole-Based Membranes as a Real Alternative to Nafion for Fuel Cells Operating at Low Temperature (pages 1339–1343)

      Piercarlo Mustarelli, Eliana Quartarone, Stefania Grandi, Arianna Carollo and Aldo Magistris

      Version of Record online: 1 APR 2008 | DOI: 10.1002/adma.200701767

      Thumbnail image of graphical abstract

      Filler up! Composite proton-conducting membranes, based on polybenzimidazole (PBI) and imidazole-derivatized silica are presented. The addition of even small amounts (∼10 wt %) of filler causes an outstanding improvement in the permanent proton conductivity by a factor <103. The preparation of PBI composite membranes with basic functionalities is a promising way to make possible their use in PEMFCs operating around 120 °C, that is, the temperature required for automotive applications.

    20. Nanometer-scale Catalyst Patterning for Controlled Growth of Individual Single-walled Carbon Nanotubes (pages 1344–1347)

      Chris Papadopoulos and Badr Omrane

      Version of Record online: 25 MAR 2008 | DOI: 10.1002/adma.200701881

      Thumbnail image of graphical abstract

      Periodic nanometer-scale patterning of sub-100 nm catalyst particles on silicon is used to grow carbon nanotubes via chemical vapor deposition from methane. The resulting structures consist of very straight individual single-walled carbon nanotubes that are preferentially aligned along perpendicular directions in the plane (see figure).

    21. FeTiTaO6: A Lead-Free Relaxor Ferroelectric Based on the Rutile Structure (pages 1348–1352)

      Rohini Mani, Srungarpu N. Achary, Keka R. Chakraborty, Sudhanshu K. Deshpande, Joby E. Joy, Abanti Nag, Jagannatha Gopalakrishnan and Avesh K. Tyagi

      Version of Record online: 25 MAR 2008 | DOI: 10.1002/adma.200701940

      Thumbnail image of graphical abstract

      High-temperature relaxor ferroelectric behavior (Tm ∼ 550 K) is reported for the rutile-based oxide, FeTiTaO6. Our investigations of the structure and dielectric properties of MTiTaO6 (M = Al, Cr, Fe) have revealed that all the oxides possess disordered rutile structure but only the iron member shows a strong relaxor ferroelectric effect. The new material is lead-free and it is based on the rutile structure, unlike the conventional relaxors which are mostly derived from the perovskite structure.

    22. Magnetic-Instability-Induced Giant Magnetoelectric Coupling (pages 1353–1356)

      Ponniah Ravindran, Ravindran Vidya, Olle Eriksson and Helmer Fjellvåg

      Version of Record online: 28 MAR 2008 | DOI: 10.1002/adma.200701889

      Thumbnail image of graphical abstract

      Multifunctional materials such as mag netoelect rics can be used in novel device applications. Magnetism and ferroelectricity coexist in some materials, but the coupling between them is very small to use them in devices. Using density function al calculations we have shown that BiCoO3 (see figure) has large magneto-electric coupling owing to metamagnetism arising from a spin state transition of cobalt ion.

    23. White Electroluminescence from a Star-like Polymer with an Orange Emissive Core and Four Blue Emissive Arms (pages 1357–1362)

      Jun Liu, Yanxiang Cheng, Zhiyuan Xie, Yanhou Geng, Lixiang Wang, Xiabin Jing and Fosong Wang

      Version of Record online: 18 MAR 2008 | DOI: 10.1002/adma.200701705

      Thumbnail image of graphical abstract

      A star-like white light-emitting polymer with an orange emissive core and four blue emissive arms is designed and synthesized. White electroluminescence is observed with simultaneous orange emission from the core and blue emission from the arms. A single-layer device based on this polymer emits white light with CIE coordinates of (0.35, 0.39) and a luminous efficiency of 7.06 cd A−1.

    24. Electric-Field-Assisted Acceleration of the Photostimulated Nematic—Isotropic Transition (pages 1363–1367)

      S. Krishna Prasad, Geetha G. Nair and V. Jayalakshmi

      Version of Record online: 3 MAR 2008 | DOI: 10.1002/adma.200701393

      Thumbnail image of graphical abstract

      The application of an electric field accelerates the recovery of the conformational E isomer from the photoinduced Z isomer Rapid return of the equilibrium nematic phase from the photo-stimulated isotropic phase of liquid crystals provides a tool to control recovery duration; useful in tailoring the value of birefringence in optical devices. Measurements point to the influence of the electric field as a general feature applicable to all systems with photoisomerizable groups.

    25. Selective Barrier Perforation in Porous Alumina Anodized on Substrates (pages 1368–1372)

      Jihun Oh and Carl V. Thompson

      Version of Record online: 25 MAR 2008 | DOI: 10.1002/adma.200701719

      Thumbnail image of graphical abstract

      A new method for perforating the barrier oxide at the base of pores in alumina, which does not involve etching of the alumina, is reported. Anodization of Al layers on W leads to formation of WO3 “plugs” that can be selectively etched without widening the as-anodized pores. We demonstrate this technique, used with templated pore formation, by creating Ni nanoelectrode arrays with fixed electrode spacings (200 nm) but varied electrode diameters.

    26. Finding Spinel in All the Wrong Places (pages 1373–1375)

      Thomas R. Hinklin, Jose Azurdia, Min Kim, Julian C. Marchal, Sameer Kumar and Richard M. Laine

      Version of Record online: 20 MAR 2008 | DOI: 10.1002/adma.200702124

      Thumbnail image of graphical abstract

      The thermal degradation products of poly(methyl meth acrylate) model compounds in an ambient atmosphere were mapped via high-resolution electrospray ionization quadrupole ion trap time of flight (Q-ToF) mass spectro metry.

    27. Selective Transfer of Insoluble Particles from a Liquid/Liquid Interface (pages 1376–1380)

      Nathanael R. Sieb and Byron D. Gates

      Version of Record online: 20 MAR 2008 | DOI: 10.1002/adma.200701567

      Thumbnail image of graphical abstract

      High-resolution patterns of insoluble particles are obtained by selectively transferring particles from a liquid-liquid interface onto a planar substrate. This technique can rapidly assemble insoluble particles of different sizes into a range of patterns over areas of at least 1 mm2.

  5. Communication

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Communications
    6. Communication
    7. Index
    8. Corrections
    1. Dendrimer–Metallomacrocycle Composites: Nanofiber Formation by Multi-Ion Pairing (pages 1381–1385)

      Pingshan Wang, Charles N. Moorefield, Kwang-Un Jeong, Seok-Ho Hwang, Sinan Li, Stephen Z. D. Cheng and George R. Newkome

      Version of Record online: 28 MAR 2008 | DOI: 10.1002/adma.200701669

      Thumbnail image of graphical abstract

      Ion-promoted, automorphogenic, and stoichiometric self-assembly of a hexameric, Ru-based macrocycle and a dendrimer produces a stable nanofiber. A structurally related larger 3rd generation dendrimer was reacted with [(112+)(PF6)12] to afford a neutral, sphere-like motif. These polyanionic counterions lead to ion-pair superstructures in which the randomness of single-charged counterions has been eliminated.

  6. Index

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Communications
    6. Communication
    7. Index
    8. Corrections
  7. Corrections

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Communications
    6. Communication
    7. Index
    8. Corrections
    1. You have free access to this content
      Multicolor Emission from Ordered Assemblies of Organic One-Dimensional Nanomaterials

      Yong Sheng Zhao, Hongbing Fu, Fengqin Hu, Ai Dong Peng and Jiannian Yao

      Version of Record online: 29 APR 2008 | DOI: 10.1002/adma.200890029

      This article corrects:

      Multicolor Emission from Ordered Assemblies of Organic 1D Nanomaterials1

      Vol. 19, Issue 21, 3554–3558, Version of Record online: 5 NOV 2007

    2. You have free access to this content
      Tunable Emission from Binary Organic One-Dimensional Nanomaterials: an Alternative Approach to White-Light Emission

      Yong Sheng Zhao, Hongbing Fu, Fengqin Hu, Aidong Peng, Wensheng Yang and Jiannian Yao

      Version of Record online: 29 APR 2008 | DOI: 10.1002/adma.200890030

      This article corrects:

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