Advanced Materials

Cover image for Vol. 24 Issue 12

March 22, 2012

Volume 24, Issue 12

Pages 1497–1615

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Masthead
    5. Contents
    6. Review
    7. Communications
    1. Microfluidics: Controlling Liquid Drops with Texture Ratchets (Adv. Mater. 12/2012) (page 1497)

      Todd A. Duncombe, E. Yegân Erdem, Ashutosh Shastry, Rajashree Baskaran and Karl F. Böhringer

      Version of Record online: 15 MAR 2012 | DOI: 10.1002/adma.201290067

      Thumbnail image of graphical abstract

      Controlled vibration selectively propels multiple microliter-sized drops along texture ratchets: microstructured tracks that rectify oscillations of the three-phase contact line into asymmetric pinning forces that propel each drop in the direction of higher pinning, as investigated by K. F. Böhringer and co-workers on page 1545. This superimposed time-lapse image depicts two pairs of 5 μL dyed water drops traveling and finally merging simultaneously on regular and upside-down texture ratchets molded in polydimethylsiloxane elastomer.

  2. Inside Front Cover

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Masthead
    5. Contents
    6. Review
    7. Communications
    1. Microsieves: Hierarchically Structured Assembly of Polymer Microsieves, made by a Combination of Phase Separation Micromolding and Float-Casting (Adv. Mater. 12/2012) (page 1498)

      Feng Yan, Ailin Ding, Míriam Gironès, Rob G. H. Lammertink, Matthias Wessling, Lars Börger, Klaus Vilsmeier and Werner A. Goedel

      Version of Record online: 15 MAR 2012 | DOI: 10.1002/adma.201290068

      Thumbnail image of graphical abstract

      The inside cover shows a hierarchically structured assembly of organic polymer microsieves prepared and characterized by W. A. Goedel and co-authors (page 1551). A “coarse” structure was prepared by phase-separation micromolding and covered by a “fine” structure, which was prepared by float-casting. These assemblies of microsieves can be handled manually without special precaution, despite the sub-micrometer thicknesses of the fine structure. The assembly shown here was used in a filtration experiment and is decorated with retained particles.

  3. Masthead

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Masthead
    5. Contents
    6. Review
    7. Communications
    1. Masthead: (Adv. Mater. 12/2012)

      Version of Record online: 15 MAR 2012 | DOI: 10.1002/adma.201290069

  4. Contents

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

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Masthead
    5. Contents
    6. Review
    7. Communications
    1. Mesoporous Silica Nanoparticles: Synthesis, Biocompatibility and Drug Delivery (pages 1504–1534)

      Fangqiong Tang, Linlin Li and Dong Chen

      Version of Record online: 29 FEB 2012 | DOI: 10.1002/adma.201104763

      Thumbnail image of graphical abstract

      Mesoporous silica nanoparticles (MSNs) are drawing growing attention for their biomedical applications. With unique mesoporous structure, high surface area and low toxicity, MSNs exhibit super performance as versatile drug delivery systems especially for cancer therapy. This review focuses on recent progresses of synthesis strategies, biocompatibility research and drug delivery application of MSNs.

  6. Communications

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Masthead
    5. Contents
    6. Review
    7. Communications
    1. Unraveling the Mechanism of Molecular Doping in Organic Semiconductors (pages 1535–1539)

      Alexander Mityashin, Yoann Olivier, Tanguy Van Regemorter, Cedric Rolin, Stijn Verlaak, Nicolas G. Martinelli, David Beljonne, Jérôme Cornil, Jan Genoe and Paul Heremans

      Version of Record online: 23 FEB 2012 | DOI: 10.1002/adma.201104269

      Thumbnail image of graphical abstract

      The mechanism by which molecular dopants donate free charge carriers to the host organic semiconductor is investigated and is found to be quite different from the one in inorganic semiconductors. In organics, a strong correlation between the doping concentration and its charge donation efficiency is demonstrated. Moreover, there is a threshold doping level below which doping simply has no electrical effect.

    2. Creation of Nanostuctures by Extreme Conditions: High-Pressure Synthesis of Ultrahard Nanocrystalline Cubic Boron Nitride (pages 1540–1544)

      Vladimir L. Solozhenko, Oleksandr O. Kurakevych and Yann Le Godec

      Version of Record online: 23 FEB 2012 | DOI: 10.1002/adma.201104361

      Thumbnail image of graphical abstract

      The synthesis of high-purity bulk nanostructured cubic boron nitride (cBN) at 20 GPa and 1770 K by direct phase transformation of graphite-like BN with an “ideal random layer” structure is reported. The two-times increase of hardness of nano-cBN (HV = 85 GPa) with respect to conventional polycrystalline cBN (HV ∼ 45 GPa) is evidently a result of nanosize effects.

    3. Controlling Liquid Drops with Texture Ratchets (pages 1545–1550)

      Todd A. Duncombe, E. Yegân Erdem, Ashutosh Shastry, Rajashree Baskaran and Karl F. Böhringer

      Version of Record online: 14 FEB 2012 | DOI: 10.1002/adma.201104446

      Thumbnail image of graphical abstract

      Controlled vibration selectively propels multiple microliter-sized drops along microstructured tracks, leading to simple microfluidic systems that rectify oscillations of the three-phase contact line into asymmetric pinning forces that propel each drop in the direction of higher pinning.

    4. Hierarchically Structured Assembly of Polymer Microsieves, made by a Combination of Phase Separation Micromolding and Float-Casting (pages 1551–1557)

      Feng Yan, Ailin Ding, Míriam Gironès, Rob G. H. Lammertink, Matthias Wessling, Lars Börger, Klaus Vilsmeier and Werner A. Goedel

      Version of Record online: 15 MAR 2012 | DOI: 10.1002/adma.201104642

      Thumbnail image of graphical abstract

      Phase separation micromolding and float-casting are combined to prepare hierarchically structured microsieves.

    5. A Selenophene-Based Low-Bandgap Donor–Acceptor Polymer Leading to Fast Ambipolar Logic (pages 1558–1565)

      Auke J. Kronemeijer, Enrico Gili, Munazza Shahid, Jonathan Rivnay, Alberto Salleo, Martin Heeney and Henning Sirringhaus

      Version of Record online: 20 FEB 2012 | DOI: 10.1002/adma.201104522

      Thumbnail image of graphical abstract

      Fast ambipolar CMOS-like logic is demonstrated using a new selenophene-based donor-acceptor polymer semiconductor. The polymer exhibits saturation hole and electron mobilities of 0.46 cm2/Vs and 0.84 cm2/Vs. Inverters are fabricated with high gains while three-stage ring oscillators show stable oscillation with an unprecedented maximum frequency of 182 kHz at a relatively low supply voltage of 50 V.

    6. Coplanar Asymmetrical Reduced Graphene Oxide–Titanium Electrodes for Polymer Photodetectors (pages 1566–1570)

      Shuping Pang, Shubin Yang, Xinliang Feng and Klaus Müllen

      Version of Record online: 20 FEB 2012 | DOI: 10.1002/adma.201104211

      Thumbnail image of graphical abstract

      Narrow gaps and a “built-in” potential originating from the different work functions of reduced graphene oxide (RGO) and titanium electrodes are used to explain the improved photosensitivity of the poly(3-hexylthiophene) photodetectors with asymmetrical RGO-Ti electrodes presented here (see figure) compared to those based on symmetrical electrodes. Easy processing, high photosensitivity, high on/off ratio, and low energy consumption contribute to the promising potential of coplanar asymmetrical electrodes in the field of photoelectric devices.

    7. Formation of Highly Ordered VO2 Nanotubular/Nanoporous Layers and Their Supercooling Effect in Phase Transitions (pages 1571–1575)

      Yang Yang, Kiyoung Lee, Mirijam Zobel, Mirza Maćković, Tobias Unruh, Erdmann Spiecker and Patrik Schmuki

      Version of Record online: 20 FEB 2012 | DOI: 10.1002/adma.201200073

      Thumbnail image of graphical abstract

      The fabrication of self-organized VO2 nanotubular/nanoporous layers is demonstrated by self-organizing anodization, followed by a suitable heat treatment. These VO2 layers show a reversible metal to insulator transition (MIT) at 70 and 44 °C, when heating and cooling, respectively.

    8. Templated Growth of Covalently Bonded Three-Dimensional Carbon Nanotube Networks Originated from Graphene (pages 1576–1581)

      Yifeng Fu, Björn Carlberg, Niklas Lindahl, Niclas Lindvall, Johan Bielecki, Aleksandar Matic, Yuxin Song, Zhili Hu, Zonghe Lai, Lilei Ye, Jie Sun, Yahui Zhang, Yan Zhang and Johan Liu

      Version of Record online: 17 FEB 2012 | DOI: 10.1002/adma.201104408

      Thumbnail image of graphical abstract

      A template-assisted method that enables the growth of covalently bonded three-dimensional carbon nanotubes (CNTs) originating from graphene at a large scale is demonstrated. Atomic force microscopy-based mechanical tests show that the covalently bonded CNT structure can effectively distribute external loading throughout the network to improve the mechanical strength of the material.

    9. Near-Infrared Thermochromic Diazapentalene Dyes (pages 1582–1588)

      Gang Qian and Zhi Yuan Wang

      Version of Record online: 20 FEB 2012 | DOI: 10.1002/adma.201104711

      Thumbnail image of graphical abstract

      A series of 2,5-diazapentalene containing dyes with tunable energy gaps are visible and near-infrared halochromic towards various acids and their protonated counterparts represent a new class of thermochromic materials with the near-infrared absorption being switched on at room temperature and off above 50 °C.

    10. A Graphite-Like Zero Gap Semiconductor with an Interlayer Separation of 2.8 Å (pages 1589–1593)

      Moni Baskey and Shyamal K Saha

      Version of Record online: 23 FEB 2012 | DOI: 10.1002/adma.201104717

      Thumbnail image of graphical abstract

      The synthesis of a highly crystalline graphite-like new material with an interlayer separation of 2.8 Å is demonstrated by re-stacking GO sheets in the form of a thin film. The optical absorption spectra and electrical data indicate that the new crystal phase is an indirect zero gap semiconductor.

    11. Facile Synthesis of Free-Standing Pd-Based Nanomembranes with Enhanced Catalytic Performance for Methanol/Ethanol Oxidation (pages 1594–1597)

      Haoxi Wu, Haijuan Li, Yujuan Zhai, Xiaolong Xu and Yongdong Jin

      Version of Record online: 20 FEB 2012 | DOI: 10.1002/adma.201104356

      Thumbnail image of graphical abstract

      Macroscopic free-standing Pd and Pd/Pt bimetallic monolayer nanomembranes (Pd- and Pd/Pt-FNMs) derived from the spontaneous self-assembly of the as-produced Pd NPs and Pd/Pt bimetallic NPs at the water–air interface within 15 min are fabricated, respectively. The one-step method allows the growth of high-quality Pd-based FNMs with well-defined monolayer morphology, which exhibit significantly higher electrocatalytic activity for methanol/ethanol oxidation than commercial catalysts.

    12. Directly Hydrothermal Growth of Single Crystal Nb3O7(OH) Nanorod Film for High Performance Dye-Sensitized Solar Cells (pages 1598–1603)

      Haimin Zhang, Yun Wang, Dongjiang Yang, Yibing Li, Hongwei Liu, Porun Liu, Barry J. Wood and Huijun Zhao

      Version of Record online: 22 FEB 2012 | DOI: 10.1002/adma.201104650

      Thumbnail image of graphical abstract

      Hydrothermal growth of high crystallinity Nb3O7(OH) single crystal nanorod film onto FTO substrate is directly used as the photoanode for DSSCs without calcination. The resultant DSSCs possess an impressive overall efficiency of 6.77%, the highest among all reported DSSCs assembled by niobium oxide-based photoanodes.

    13. One-Step Fabrication of Graded Rainbow-Colored Holographic Photopolymer Reflection Gratings (pages 1604–1609)

      Ke Liu, Huina Xu, Haifeng Hu, Qiaoqiang Gan and Alexander N. Cartwright

      Version of Record online: 22 FEB 2012 | DOI: 10.1002/adma.201104628

      Thumbnail image of graphical abstract

      A one-step fabrication method has been developed to realize graded holographic photopolymer reflection gratings with gradually varied period in the lateral direction, leading to a rainbow-colored reflection image in the same viewing angle. This low-cost rainbow-colored filter can be integrated with detectors or imaging devices to realize compact and portable spectroscopic analyzers.

    14. Epitaxial Ferroelectric Heterostructures Fabricated by Selective Area Epitaxy of SrRuO3 Using an MgO Mask (pages 1610–1615)

      J. Karthik, Anoop R. Damodaran and Lane W. Martin

      Version of Record online: 22 FEB 2012 | DOI: 10.1002/adma.201104697

      Thumbnail image of graphical abstract

      Illustration of a new high-temperature hard-mask process based on traditional lithography and selective wet-etching of MgO. The hard mask is compatible with standard nano-lithography techniques and heat treatments in excess of 1000 °C. Here, this technique is applied to produce temperature-stable contacts that give rise to low leakage, improved fatigue properties, and excellent high-temperature stability in ferroelectric thin-film capacitors.

SEARCH

SEARCH BY CITATION