Advanced Materials

Cover image for Vol. 22 Issue 16

April 22, 2010

Volume 22, Issue 16

Pages 1775–1884

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Frontispiece
    6. Reviews
    7. Communications
    1. Carbon Nanotubes: 100 mm Long, Semiconducting Triple-Walled Carbon Nanotubes (Adv. Mater. 16/2010)

      Qian Wen, Weizhong Qian, Jingqi Nie, Anyuan Cao, Guoqing Ning, Yao Wang, Ling Hu, Qiang Zhang, Jiaqi Huang and Fei Wei

      Version of Record online: 21 APR 2010 | DOI: 10.1002/adma.201090053

      Thumbnail image of graphical abstract

      100 mm long semiconducting triple-walled carbon nanotubes (TWNTs) with uniform sections of up to 35 mm having the same chirality index, can be obtained by a gas-flow-directed growth method, as reported by Weizhong Qian and co-workers on p. 1867. The chiral angle distributions of the TWNTs were dominantly between 20° and 30°. The maximum current density sustained by each shell could reach up to 3.7 ×108 A/cm2.

  2. Inside Front Cover

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Frontispiece
    6. Reviews
    7. Communications
    1. Noble Metal Nanoparticles: (Adv. Mater. 16/2010)

      Tapan K. Sau and Andrey L. Rogach

      Version of Record online: 21 APR 2010 | DOI: 10.1002/adma.201090054

      Thumbnail image of graphical abstract

      Bottom-up colloid chemical synthesis has emerged as a powerful and economical design tool for morphology control in metal nanoparticles. The anisotropy of non-spherical noble metal particles leads to novel properties and therefore to new potential applications, ranging from catalysis to cellular imaging, label-free biosensing and photothermal therapy. On pages 1781 and 1805, Andrey Rogach and co-workers review the synthesis and properties of such nanoparticles.

  3. Contents

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Frontispiece
    6. Reviews
    7. Communications
  4. Frontispiece

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Frontispiece
    6. Reviews
    7. Communications
    1. Carbon Nanotube Arrays: Improved Density in Aligned Arrays of Single-Walled Carbon Nanotubes by Sequential Chemical Vapor Deposition on Quartz (Adv. Mater. 16/2010)

      Suck Won Hong, Tony Banks and John A. Rogers

      Version of Record online: 21 APR 2010 | DOI: 10.1002/adma.201090056

      Thumbnail image of graphical abstract

      This colorized, perspective view scanning electron microscopy (SEM) image shows aligned arrays of single-walled carbon nanotubes grown on a quartz substrate in two sequential cycles of chemical vapor deposition (red and blue), as reported by John Rogers and co-workers on p. 1826. The gold line depicts an electrode contact to the array. The SEM image in the background shows regions of dual and single growth on the left and right, respectively.

  5. Reviews

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Frontispiece
    6. Reviews
    7. Communications
    1. Nonspherical Noble Metal Nanoparticles: Colloid-Chemical Synthesis and Morphology Control (pages 1781–1804)

      Tapan K. Sau and Andrey L. Rogach

      Version of Record online: 28 DEC 2009 | DOI: 10.1002/adma.200901271

      Thumbnail image of graphical abstract

      Noble metal nanoparticles with an impressive range of morphologies, such as rods, wires, stars, boxes, etc. can be produced by a colloid-chemical approach (see figure). This article reviews the recent progress in the colloid-chemical synthesis of nonspherical nanoparticles of a few important noble metals (mainly Ag, Au, Pd, and Pt). The article focuses on various factors that influence the particle morphology and the mechanisms of the nonspherical-shape evolution.

    2. Properties and Applications of Colloidal Nonspherical Noble Metal Nanoparticles (pages 1805–1825)

      Tapan K. Sau, Andrey L. Rogach, Frank Jäckel, Thomas A. Klar and Jochen Feldmann

      Version of Record online: 4 JAN 2010 | DOI: 10.1002/adma.200902557

      Thumbnail image of graphical abstract

      Colloidal synthesis of noble metal nanoparticles results in a great variety of morphologies. This review deals with morphology-dependent properties and applications of nonspherical noble metal nanoparticles, with a focus on localized surface plasmon resonance and local field enhancement, as well as their applications in various fields including Raman spectroscopy, fluorescence enhancement, analytics and sensing, photothermal therapy, (bio-)diagnostics, and imaging.

  6. Communications

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Frontispiece
    6. Reviews
    7. Communications
    1. Improved Density in Aligned Arrays of Single-Walled Carbon Nanotubes by Sequential Chemical Vapor Deposition on Quartz (pages 1826–1830)

      Suck Won Hong, Tony Banks and John A. Rogers

      Version of Record online: 7 JAN 2010 | DOI: 10.1002/adma.200903238

      Thumbnail image of graphical abstract

      An approach to formation of high-density, horizontally aligned arrays of pristine, individual single-walled carbon nanotubes (see image) is presented. The method involves multiple cycles of chemical vapor deposition growth to achieve densities and levels of uniformity in coverage better than those previously possible.

      Corrected by:

      Correction: Correction: Improved Density in Aligned Arrays of Single-Walled Carbon Nanotubes by Sequential Chemical Vapor Deposition on Quartz

      Vol. 22, Issue 45, 5081, Version of Record online: 30 NOV 2010

    2. Learning Abilities Achieved by a Single Solid-State Atomic Switch (pages 1831–1834)

      Tsuyoshi Hasegawa, Takeo Ohno, Kazuya Terabe, Tohru Tsuruoka, Tomonobu Nakayama, James K. Gimzewski and Masakazu Aono

      Version of Record online: 9 FEB 2010 | DOI: 10.1002/adma.200903680

      Thumbnail image of graphical abstract

      Learning abilities are demonstrated using a single solid-state atomic switch, wherein the formation and dissolution of a metal filament are controlled depending on the history of prior switching events. The strength of the memorization level gradually increases when the number of input signals is increased. Once the filament forms a bridge, electrons flow in a ballistic mode and long-term memorization is achieved (see figure).

    3. Self-Assembly and Charge-Transport Properties of a Polythiophene–Fullerene Triblock Copolymer (pages 1835–1839)

      Mark Dante, Changduk Yang, Bright Walker, Fred Wudl and Thuc-Quyen Nguyen

      Version of Record online: 9 FEB 2010 | DOI: 10.1002/adma.200902696

      Thumbnail image of graphical abstract

      A rod–coil triblock copolymer consisting of a poly(3-hexylthiophene) (P3HT) rigid block, a styrene coil block, and a coil block with fullerene pendant group has been synthesized (see figure). Nanofibers in films reach 250 nm in length and 10.7 nm in width. Photo- and dark-current imaging by conducting atomic force microscopy reveals that the fibers are highly conductive. The electron and hole mobilities are comparable with a P3HT:fullerene-derivative blend.

    4. Contact-Printed Microelectromechanical Systems (pages 1840–1844)

      Corinne E. Packard, Apoorva Murarka, Eric W. Lam, Martin A. Schmidt and Vladimir Bulović

      Version of Record online: 12 FEB 2010 | DOI: 10.1002/adma.200903034

      Thumbnail image of graphical abstract

      A process for rapid fabrication of metallic MEMS (microelectromechanical systems) without lithographic processing is presented. Using dimensionally scalable contact printing, 3D electromechanical structures (see figure) are fabricated and functionally tested. Flexible, paper-thin device arrays produced by this method may enable such applications as pressure sensing skins for people and vehicles, phased array detectors for acoustic imaging, and novel adaptive-texture display applications.

    5. Ultralow-Platinum-Loading High-Performance Nanoporous Electrocatalysts with Nanoengineered Surface Structures (pages 1845–1848)

      Rongyue Wang, Chao Wang, Wen-Bin Cai and Yi Ding

      Version of Record online: 21 JAN 2010 | DOI: 10.1002/adma.200903548

      Thumbnail image of graphical abstract

      A robust new electrocatalyst with ultralow Pt loading, great poisoning resistance, and high stability (see figure) shows an over 100-fold increase in the efficiency of formic acid electro-oxidation, compared with the commercial Pt/C catalyst. In situ IR spectroscopy proves that the greatly enhanced performance is mainly achieved by changing reaction pathways using Au clusters, which simultaneously improve the stability.

    6. Optical Outcoupling Enhancement in Organic Light-Emitting Diodes: Highly Conductive Polymer as a Low-Index Layer on Microstructured ITO Electrodes (pages 1849–1853)

      Tae-Wook Koh, Jung-Min Choi, Sunghun Lee and Seunghyup Yoo

      Version of Record online: 8 FEB 2010 | DOI: 10.1002/adma.200903375

      Thumbnail image of graphical abstract

      A highly conductive polymer layer coated on a microstructured indium tin oxide (ITO) electrode is proposed as a simple way to enhance outcoupling in organic light-emitting diodes. The relatively low refractive index of the conductive polymer provides an index contrast between the organic and ITO layers so that structuring of ITO electrodes can result in a significant optical effect.

    7. Electrical Properties and Photoconductivity of Stacked-Graphene Carbon Nanotubes (pages 1854–1857)

      Eduardo. J. H. Lee, Linjie Zhi, Marko Burghard, Klaus Müllen and Klaus Kern

      Version of Record online: 26 FEB 2010 | DOI: 10.1002/adma.200903462

      Thumbnail image of graphical abstract

      Stacked-graphene carbon nanotubes (SG-CNTs) obtained via pyrolysis of columnar superstructures of polycyclic aromatic hydrocarbons are studied by electrical transport measurements and scanning photocurrent microscopy. The charge transport in individual SG-CNTs (see figure) is found to be dominated by variable range hopping. Their photoconductive properties render the SG-CNTs of interest for photodetector applications.

    8. Collagen Biomineralization In Vivo by Sustained Release of Inorganic Phosphate Ions (pages 1858–1862)

      Pamela Habibovic, David C. Bassett, Charles J. Doillon, Catherine Gerard, Marc D. McKee and Jake E. Barralet

      Version of Record online: 9 FEB 2010 | DOI: 10.1002/adma.200902778

      Thumbnail image of graphical abstract

      A new strategy for mineralized tissue formation in vivo is presented based on localized sustained delivery of inorganic orthophosphate (Pi) sufficient to supersaturate tissue surrounding an implant and induce mineralization of collagen. After 15 days implantation mineral formation around the implants was detected. Histology and electron microscopy show two populations of apatite; inter-fibrillar microcrystals and nanocrystals associated with collagen.

    9. Electrochemical Nanotransistor from Mixed-Polymer Brushes (pages 1863–1866)

      Tsz Kin Tam, Marcos Pita, Mikhail Motornov, Ihor Tokarev, Sergiy Minko and Evgeny Katz

      Version of Record online: 9 FEB 2010 | DOI: 10.1002/adma.200903610

      Thumbnail image of graphical abstract

      Reversible switching of the electrode interface between OFF/ON states is achieved by electrochemically triggered reorganization of a nanostructured polymer brush associated with the interface. The switching process is accomplished by local interfacial pH changes allowing operation in buffered biological environments (see figure). The fabricated device mimics the performance of switching electronic devices such as transistors.

    10. 100 mm Long, Semiconducting Triple-Walled Carbon Nanotubes (pages 1867–1871)

      Qian Wen, Weizhong Qian, Jingqi Nie, Anyuan Cao, Guoqing Ning, Yao Wang, Ling Hu, Qiang Zhang, Jiaqi Huang and Fei Wei

      Version of Record online: 7 JAN 2010 | DOI: 10.1002/adma.200902746

      Thumbnail image of graphical abstract

      Direct growth of 100 mm long, semiconducting triple-walled carbon nanotubes (TWNTs) on Si substrates by chemical vapor depoistion is reported. By tailoring the temperature for a certain gas flow rate, a yield of nearly 90% of centimeter-long TWNTs is obtained. The TWNTs show an unprecedented structural homogeneity, in which each shell maintains a constant chiral index extending over a very large distance (>60 mm). The semiconducting TWNTs can be directly fabricated into field-effect transistors.

    11. High-Efficiency Deep-Blue-Phosphorescent Organic Light-Emitting Diodes Using a Phosphine Oxide and a Phosphine Sulfide High-Triplet-Energy Host Material with Bipolar Charge-Transport Properties (pages 1872–1876)

      Soon Ok Jeon, Kyoung Soo Yook, Chul Woong Joo and Jun Yeob Lee

      Version of Record online: 24 FEB 2010 | DOI: 10.1002/adma.200903321

      Thumbnail image of graphical abstract

      Highly efficient deep-blue-phosphorescent organic light-emitting diodes have been developed using bipolar-type high-triplet-energy host materials with a carbazole core and two phosphine oxide (PPO21) or phosphine sulfide (PPS21) units. A high quantum efficiency of 19.2% with a deep-blue color coordinate of (0.14,0.16) was achieved in the deep-blue device with PPO21 as a host material (see figure).

    12. Low-Threshold Electrically Pumped Random Lasers (pages 1877–1881)

      Hai Zhu, Chong-Xin Shan, Ji-Ying Zhang, Zhen-Zhong Zhang, Bing-Hui Li, Dong-Xu Zhao, Bin Yao, De-Zhen Shen, Xi-Wu Fan, Zi-Kang Tang, Xianghui Hou and Kwang-Leong Choy

      Version of Record online: 12 FEB 2010 | DOI: 10.1002/adma.200903623

      Thumbnail image of graphical abstract

      Electrically pumped random lasers are realized in ZnO nanocrystallite films in a simple metal–oxide–semiconductor structure. By introducing an i-ZnO layer, a threshold current of 6.5 mA is obtained. The reported results provide a simple route to electrically pumped random lasing (see figure) with relatively low threshold, a significant step towards the future applications of this kind of laser.

    13. Self-Assembly of Block Copolymers on Flexible Substrates (pages 1882–1884)

      Soojin Park, Dong Hyun Lee and Thomas P. Russell

      Version of Record online: 3 FEB 2010 | DOI: 10.1002/adma.200902722

      Thumbnail image of graphical abstract

      A simple route is demonstrated to fabricate highly ordered and oriented arrays of PS-b-PEO block copolymer microdomains on inexpensive, flexible polymeric substrates where the lateral ordering is the same as that seen on hard master surfaces. The block copolymer thin films well-developed onto flexible substrates can be used as templates or scaffolds to fabricate a wide range of nanostructured materials for inexpensive, flexible devices.

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