Advanced Materials

Cover image for Vol. 21 Issue 38‐39

October 19, 2009

Volume 21, Issue 38-39

Pages 3817–3957

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Reports
    7. Reviews
    8. Communications
    9. Communication
    1. Gyroid Single Crystals: Nanostructured Calcite Single Crystals with Gyroid Morphologies (Adv. Mater. 38–39/2009)

      Alexander S. Finnemore, Maik R. J. Scherer, Richard Langford, Sumeet Mahajan, Sabine Ludwigs, Fiona C. Meldrum and Ullrich Steiner

      Version of Record online: 16 OCT 2009 | DOI: 10.1002/adma.200990146

      Thumbnail image of graphical abstract

      Single crystals typically assume a crystallographically distinct shape. Many biological organisms, however, synthesize single crystals with an intricate mescoscopic morphology that does not reflect the crystal symmetry. The cover shows a calcite single crystal with a bicontinuous gyroid morphology, which was obtained by calcite nucleation in a self-assembled polymer matrix in work reported by Ulli Steiner and co-workers on p. 3928. The characteristic size of the biomimetic structure is ∼30 nm. The pattern in the title is the characteristic 211 plane of the gyroid morphology.

  2. Inside Front Cover

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Reports
    7. Reviews
    8. Communications
    9. Communication
    1. Liquid Crystals: Electrically Tuneable Liquid Crystal Photonic Bandgaps (Adv. Mater. 38–39/2009)

      Su Seok Choi, Stephen M. Morris, Wilhelm T. S. Huck and Harry J. Coles

      Version of Record online: 16 OCT 2009 | DOI: 10.1002/adma.200990147

      Thumbnail image of graphical abstract

      On p. 3915, Stephen Morris and co-workers demonstrate broadband wavelength tuning of a photonic bandgap that is electrically driven in a chiral nematic liquid crystal. Remarkably, this tuning is not only broadband but is found to occur without altering the reflection quality of the optical structure. In addition, under certain conditions, the helical structure can be made to exhibit multiple bandgaps across the visible spectrum.

  3. Contents

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Reports
    7. Reviews
    8. Communications
    9. Communication
  4. Editorial

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Reports
    7. Reviews
    8. Communications
    9. Communication
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  5. Progress Reports

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Reports
    7. Reviews
    8. Communications
    9. Communication
    1. The Materials Science of Functional Oxide Thin Films (pages 3827–3839)

      Mark G. Blamire, Judith L. MacManus-Driscoll, Neil D. Mathur and Zoe H. Barber

      Version of Record online: 5 AUG 2009 | DOI: 10.1002/adma.200900947

      Thumbnail image of graphical abstract

      Much of the potential of functional oxideslies in the tuneability of their properties. Here we review novel properties that precision thin-film growth has revealed, and the extent that these properties can be coupled at interfaces. For example, the figure shows an ordered nanocomposite structure with three-dimensional epitaxial registration; the internal strains in such structures can be used to modify bulk properties of oxides.

    2. Conjugated-Polymer Blends for Optoelectronics (pages 3840–3850)

      Christopher R. McNeill and Neil C. Greenham

      Version of Record online: 16 JUL 2009 | DOI: 10.1002/adma.200900783

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      Conjugated-polymer blends can be solution processed to form the active layer in efficient organic light-emitting diodes and solar cells. In this progress report, we discuss recent advances in imaging blend microstructure, and we demonstrate how the blend structure leads to performance advantages in both LEDs and photovoltaic devices.

  6. Reviews

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Reports
    7. Reviews
    8. Communications
    9. Communication
    1. The Coming of Advanced Materials: A Personal View of the Contributions by Cambridge Scientists (pages 3851–3858)

      John Meurig Thomas

      Version of Record online: 7 AUG 2009 | DOI: 10.1002/adma.200900898

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      Of the many contributions to the characterization of advanced materials by Cambridge scientists, those devoted to electron microscopy reign supreme. The wealth of structural and electronic information extractable from electron-energy-loss spectroscopy and imaging is illustrated graphically here.

    2. Reliability of Organic Field-Effect Transistors (pages 3859–3873)

      Henning Sirringhaus

      Version of Record online: 5 AUG 2009 | DOI: 10.1002/adma.200901136

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      The current understanding of the reliability of organic field-effect transistors is reviewed. We discuss the various factors that have been found to influence the operational stability and charge trapping in the channel. A key question concerns the role of extrinsic factors, such as oxidation or presence of moisture, and that of intrinsic factors related to inherent structural disorder.

    3. Nanotube–Polymer Composites for Ultrafast Photonics (pages 3874–3899)

      Tawfique Hasan, Zhipei Sun, Fengqiu Wang, Francesco Bonaccorso, Ping Heng Tan, Aleksey G. Rozhin and Andrea C. Ferrari

      Version of Record online: 16 OCT 2009 | DOI: 10.1002/adma.200901122

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      Carbon nanotube–polymer composites offer a flexible and cheap wet-chemistry-based route to photonic device fabrication. These are prepared by dispersing nanotubes, which are ideal saturable absorbers, in solvents compatible with the target host polymer. These composites can then be used to generate ultrashort laser pulses by passive mode-locking in fiber-laser cavities.

  7. Communications

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Reports
    7. Reviews
    8. Communications
    9. Communication
    1. The Influence of α-Tricalcium Phosphate Nanoparticles and Microparticles on the Degradation of Poly(D,L-lactide-co-glycolide) (pages 3900–3904)

      Zhijie Yang, Serena M. Best and Ruth E. Cameron

      Version of Record online: 16 JUL 2009 | DOI: 10.1002/adma.200901093

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      The in vitro degradation behavior of a series of resorbable, bioactive nano- and microcomposites designed for orthopaedic application is explored. Nanoparticles of α-tricalcium phosphate are significantly more effective than the equivalent microparticles in reducing heterogeneity of the poly(D,L-lactide-co-glycolide) degradation. More uniform degradation, reduced acid release, and less swelling of polymer were observed.

    2. Improving Mechanical Properties of Crystalline Solids by Cocrystal Formation: New Compressible Forms of Paracetamol (pages 3905–3909)

      Shyam Karki, Tomislav Friščić, László Fábián, Peter R. Laity, Graeme M. Day and William Jones

      Version of Record online: 17 JUL 2009 | DOI: 10.1002/adma.200900533

      Thumbnail image of graphical abstract

      Poor mechanical properties of paracetamol are improved through the strategy of cocrystal formation. Mechanochemical screening by liquid-assisted grinding generated four cocrystals of paracetamol that readily form tablets by direct compression. Computational studies reveal the mechanical properties can be related to structural features, before all the formation of hydrogen-bonded layers.

    3. Synthetic pH-Responsive Polymers for Protein Transduction (pages 3910–3914)

      William B. Liechty, Rongjun Chen, Farzin Farzaneh, Mahvash Tavassoli and Nigel K. H. Slater

      Version of Record online: 24 JUL 2009 | DOI: 10.1002/adma.200901733

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      A pH-responsive, endosomal membrane disruptive, metabolite-derived polyamide PP-75 is developed to deliver the MBP-Apoptin fusion protein, which induces tumor-specific apoptosis into human osteogenic sarcoma Saos-2 cells. The intracellular distribution and colocalization of MBP-Apoptin-AF647 (MA-AF649) and PP-75-FITC provide strong evidence that PP-75 both enhances uptake and facilitates cytoplasmic release of MBP-Apoptin.

    4. Electrically Tuneable Liquid Crystal Photonic Bandgaps (pages 3915–3918)

      Su Seok Choi, Stephen M. Morris, Wilhelm T. S. Huck and Harry J. Coles

      Version of Record online: 24 JUL 2009 | DOI: 10.1002/adma.200900916

      Thumbnail image of graphical abstract

      Electrically controlled color tuning of the photonic bandgap and electrically induced multiple photonic bandgaps from a chiral nematic liquid crystal mixture doped with a ferroelectric liquid crystal.

    5. Arrays of Parallel Connected Coaxial Multiwall-Carbon- Nanotube–Amorphous-Silicon Solar Cells (pages 3919–3923)

      Hang Zhou, Alan Colli, Arman Ahnood, Yang Yang, Nalin Rupesinghe, Tim Butler, Ibraheem Haneef, Pritesh Hiralal, Arokia Nathan and Gehan A. J. Amaratunga

      Version of Record online: 17 AUG 2009 | DOI: 10.1002/adma.200901094

      Thumbnail image of graphical abstract

      Arrays of parallel connected coaxial multiwall-carbon-nanotube–amorphous-silicon solar cells are fabricated. In this configuration, orthogonalization of the directions of light absorption and charge-carrier collection is realized. Under simulated solar illumination (AM 1.5 G), the short-circuit current of our carbon-nanotube enhanced solar cell is ∼25% higher than that of the planar cell.

    6. Correlation of Heterojunction Luminescence Quenching and Photocurrent in Polymer-Blend Photovoltaic Diodes (pages 3924–3927)

      Astrid Gonzalez-Rabade, Arne C. Morteani and Richard H. Friend

      Version of Record online: 19 AUG 2009 | DOI: 10.1002/adma.200901114

      Thumbnail image of graphical abstract

      Charge generation in organic solar cells proceeds via photogeneration of excitons in the bulk that form geminate electron–hole pairs at the heterojunction formed between electron donor and acceptors. It is shown that an externally applied electric field increases the number of free charges formed from the geminate pair, and quenches the luminescence from the relaxed exciplex with one-to-one correspondence.

    7. Nanostructured Calcite Single Crystals with Gyroid Morphologies (pages 3928–3932)

      Alexander S. Finnemore, Maik R. J. Scherer, Richard Langford, Sumeet Mahajan, Sabine Ludwigs, Fiona C. Meldrum and Ullrich Steiner

      Version of Record online: 28 AUG 2009 | DOI: 10.1002/adma.200900615

      Thumbnail image of graphical abstract

      Gyroid-structured calcite crystals are grown by templating though self-assembled copolymer films. The remarkable triply periodic minimal surface is perfectly replicated on the nanometer scale, while single crystallinity is maintained. This is a wholly synthetic route to a crystal morphology found in biological systems, only on a smaller length scale.

    8. Scalable Cylindrical Metallodielectric Metamaterials (pages 3933–3936)

      Nicholas Gibbons, Jeremy J. Baumberg, Chris L. Bower, Mathias Kolle and Ullrich Steiner

      Version of Record online: 20 JUL 2009 | DOI: 10.1002/adma.200900461

      Thumbnail image of graphical abstract

      A novel approach for fabricating metallodielectric metamaterials is reported through the exploitation of a floated roll technique. This process offers an efficient and scalable fabrication route for these multilayer structures, obviating the need for multiple depositions. These nanostructures can offer exciting new optical properties such as negative refraction and sub-wavelength imaging.

    9. Polymer-Mediated Dispersion of Gold Nanoparticles: Using Supramolecular Moieties on the Periphery (pages 3937–3940)

      Adam D. Celiz, Tung-Chun Lee and Oren A. Scherman

      Version of Record online: 3 SEP 2009 | DOI: 10.1002/adma.200901291

      Thumbnail image of graphical abstract

      A novel method of dispersing gold nanoparticles (Au NPs) is described. Thiol-terminated ureido-pyrimidinone (UPy)-functionalized polymers are attached to Au NPs to create a polymeric shell with quadruple hydrogen-bonding units on the periphery. By increasing the amount of UPy loading on the Au NPs, self-assembly into aggregates is observed with both 1H NMR spectroscopy and transmission electron microscopy.

    10. The Spatial Distribution of Threading Dislocations in Gallium Nitride Films (pages 3941–3944)

      Michelle A. Moram, Rachel A. Oliver, Menno J. Kappers and Colin J. Humphreys

      Version of Record online: 8 SEP 2009 | DOI: 10.1002/adma.200901095

      Thumbnail image of graphical abstract

      Spatial analysis techniques are used to study threading dislocations (TDs) at the surfaces of a wide range of GaN films. In all films, the dislocation positions are consistent with a spatially random TD generation process followed by movement of dislocations, but are inconsistent with the spatial distribution of dislocations expected at island coalescence boundaries.

    11. Strength of Nanotubes, Filaments, and Nanowires From Sonication-Induced Scission (pages 3945–3948)

      Yan Y. Huang, Tuomas P. J. Knowles and Eugene M. Terentjev

      Version of Record online: 8 SEP 2009 | DOI: 10.1002/adma.200900498

      Thumbnail image of graphical abstract

      A model to describe the cavitation-induced breakage of nanofilaments during their sonication in solution is proposed. The model predicts a limiting length below which scission no longer occurs, and accurately describes experimental results for materials ranging from carbon nanotubes to protein fibrils. Sonication-induced breakage can now be used as a probe for the strength of nanostructures.

    12. Ultrabubble: A Laminated Ultrasound Contrast Agent with Narrow Size Range (pages 3949–3952)

      Pei-Lun Lin, Robert J. Eckersley and Elizabeth A. H. Hall

      Version of Record online: 28 AUG 2009 | DOI: 10.1002/adma.200901096

      Thumbnail image of graphical abstract

      A laminated shell microcapsule is described resisting aggregation and withstanding ultrasound destruction, showing a good backscatter signal, as shown in the figure. Templated synthesis produces versatile monodisperse capsules <3 µm, with ultrasound-pressure dependency allowing rupture above MI ∼ 1.5 (at 2 MHz), suitable for future development as both controlled-delivery agent and contrast agent.

  8. Communication

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Reports
    7. Reviews
    8. Communications
    9. Communication
    1. The Use of Terahertz Spectroscopy as a Sensitive Probe in Discriminating the Electronic Properties of Structurally Similar Multi-Walled Carbon Nanotubes (pages 3953–3957)

      Edward P. J. Parrott, J. Axel Zeitler, James McGregor, Shu-Pei Oei, H. Emrah Unalan, William I. Milne, Jean-Philippe Tessonnier, Dang Sheng Su, Robert Schlögl and Lynn F. Gladden

      Version of Record online: 14 JUL 2009 | DOI: 10.1002/adma.200900941

      Thumbnail image of graphical abstract

      Terahertz spectroscopy is used to definitively distinguish between two multiwalled carbon nanotubes (see figure), which have commercial applications in a number of advanced materials. Other techniques do not provide a sensitive discrimination of the measured properties. This observation is rationalized by considering the dielectric nature of the materials and the relationship of this to their structural differences.

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