Advanced Materials

Cover image for Vol. 22 Issue 43

November 16, 2010

Volume 22, Issue 43

Pages 4783–4909

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Progress Report
    6. Communications
    1. Drug Delivery: Nano-Layered Microneedles for Transcutaneous Delivery of Polymer Nanoparticles and Plasmid DNA (Adv. Mater. 43/2010) (page 4783)

      Peter C. DeMuth, Xingfang Su, Raymond E. Samuel, Paula T. Hammond and Darrell J. Irvine

      Article first published online: 11 NOV 2010 | DOI: 10.1002/adma.201090139

      Thumbnail image of graphical abstract

      A new strategy to create biodegradable drug-loaded coatings on microneedle patches, using a process known as layer-by-layer (LbL) self-assembly, is reported on p. 4851 by Paula Hammond and coworkers. Water-soluble polymers are adsorbed with oppositely-charged drugs or drug-carrying polymer particles in alternating layers, creating extremely thin coatings loaded with high levels of entrapped drugs. These biodegradable films can be used to deposit DNA or drug-carrier nanoparticles into the skin, representing model drug cargos that could be used for vaccination or other therapeutic drug delivery.

  2. Inside Front Cover

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Progress Report
    6. Communications
    1. Templated Structures: Bicontinuous Macroporous Materials from Bijel Templates (Adv. Mater. 43/2010) (page 4784)

      Matthew N. Lee and Ali Mohraz

      Article first published online: 11 NOV 2010 | DOI: 10.1002/adma.201090140

      Thumbnail image of graphical abstract

      A metallic structure that resembles a percolating spinodal interface is one of several novel materials that can be synthesized from bijel templates, as reported by Ali Mohraz and co-workers on p. 4836. The method provides a versatile platform for the synthesis of ceramic, metallic, and polymeric materials and composites with tunable bicontinuous morphology.

  3. Contents

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Progress Report
    6. Communications
    1. Contents: (Adv. Mater. 43/2010) (pages 4785–4791)

      Article first published online: 11 NOV 2010 | DOI: 10.1002/adma.201090141

  4. Progress Report

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Progress Report
    6. Communications
    1. Design Considerations for Plasmonic Photovoltaics (pages 4794–4808)

      Vivian E. Ferry, Jeremy N. Munday and Harry A. Atwater

      Article first published online: 2 SEP 2010 | DOI: 10.1002/adma.201000488

      Thumbnail image of graphical abstract

      Plasmonic nanostructures can be used to enhance absorption in a variety of solar cells, including c-Si, a-Si:H, GaAs, and various organic devices. This review discusses the variety of geometries for plasmonic nanostructure incorporation, including top structures, back-contact structures, and embedded structures. The article focuses on the reduction in cell thickness achievable via coupling to waveguide modes, and on the potential for enhanced absorption in other material systems.

  5. Communications

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Progress Report
    6. Communications
    1. Photo-Curable Polymer Blend Dielectrics for Advancing Organic Field-Effect Transistor Applications (pages 4809–4813)

      Se Hyun Kim, Kipyo Hong, Mi Jang, Jaeyoung Jang, John E. Anthony, Hoichang Yang and Chan Eon Park

      Article first published online: 3 SEP 2010 | DOI: 10.1002/adma.201000904

      Thumbnail image of graphical abstract

      A solution method of photo-curable and -patternable polymer gate dielectrics was introduced by using blend solutions of poly(4-dimethylsilyl styrene) (PDMSS) and poly(melamine-co-formaldehyde) acrylate (PMFA). The fabrication was optimized to produce a smooth hydrophobic gate dielectric with good insulating and solvent-resistant properties. On the optimized PDMSS/PMFA blend gate dielectric, pentacene could grow into highly ordered structure, showing high electric performances for the resulting OFETs, as well as PTCDI-C13 and TES-ADT.

    2. Magnetic Liquid Marbles: A “Precise” Miniature Reactor (pages 4814–4818)

      Yuhua Xue, Hongxia Wang, Yan Zhao, Liming Dai, Lianfang Feng, Xungai Wang and Tong Lin

      Article first published online: 31 AUG 2010 | DOI: 10.1002/adma.201001898

      Thumbnail image of graphical abstract

      Magnetic liquid marbles capable of hosting both aqueous and organic fluids may serve as new miniature chemical reactors. Chemical reactions can occur either within a single liquid marble or between two magnetic liquid marbles (as illustrated). The liquid marbles can also interact with external devices simply by opening and closing the powdery shell under a magnetic field.

    3. Coexistence of Filamentary and Homogeneous Resistive Switching in Fe-Doped SrTiO3 Thin-Film Memristive Devices (pages 4819–4822)

      Ruth Muenstermann, Tobias Menke, Regina Dittmann and Rainer Waser

      Article first published online: 27 AUG 2010 | DOI: 10.1002/adma.201001872

      Thumbnail image of graphical abstract

      Conductive atomic force microscopy combined with a delamination technique is used to remove the top electrode of Fe-doped SrTiO3 metal–insulator–metal structures and gain insight into the active switching interface. Both a filamentary and an area-dependent switching process with opposite switching polarities are found in the same sample.

    4. A Biomimetic, Self-Pumping Membrane (pages 4823–4825)

      In-Kook Jun and Henry Hess

      Article first published online: 13 SEP 2010 | DOI: 10.1002/adma.201001694

      Thumbnail image of graphical abstract

      Biological membranes accelerate materials exchange by active, ATP-dependent transport through specialized channel proteins. Similarly, the integration of “pumping” driven by chemical energy harvested from the fluid into a synthetic membrane is highly desirable from an engineering point of view. Here, a novel membrane integrating an electroosmotic micropump with a fuel cell is described. Future applications of such self-pumping membranes operating with a variety of fuels may include implantable or remotely operating autonomous devices and membrane-based purification systems.

    5. Bio-Inspired Hierarchical Macromolecule–Nanoclay Hydrogels for Robust Underwater Superoleophobicity (pages 4826–4830)

      Ling Lin, Mingjie Liu, Li Chen, Peipei Chen, Jie Ma, Dong Han and Lei Jiang

      Article first published online: 31 AUG 2010 | DOI: 10.1002/adma.201002192

      Thumbnail image of graphical abstract

      Robustunderwater superoleophobicity – oil repellence that is stable under loading – is achieved by constructing hierarchical macromolecule-nanoclay hydrogels (see images), inspired by the oil-repellent nature of the composite surface of fish. The synergetic effect of micro-/nanostructures and the mechanical strength of hybrid hydrogels in general supports the stability of trapped water on the hydrogel surface, endowing hybid hydrogels with robust superoleophobicity (upper right inset) even under loading forces.

    6. Endothelial Cell Guidance in 3D Patterned Scaffolds (pages 4831–4835)

      Yukie Aizawa, Ryan Wylie and Molly Shoichet

      Article first published online: 11 NOV 2010 | DOI: 10.1002/adma.201001855

      Thumbnail image of graphical abstract

      Primary endothelial cells are guided in an agarose hydrogel scaffold that is chemically patterned with an immobilized concentration gradient of VEGF165 using multiphoton laser patterning. It is particularly compelling that, in this 3D patterned hydrogel, endothelial cells differentiate to tip and stalk cells, having the morphology that is observed in vivo.

    7. Bicontinuous Macroporous Materials from Bijel Templates (pages 4836–4841)

      Matthew N. Lee and Ali Mohraz

      Article first published online: 22 SEP 2010 | DOI: 10.1002/adma.201001696

      Thumbnail image of graphical abstract

      Particle-stabilized emulsion gels, or bijels, are used as a general platform for the synthesis of bicontinuous composite materials with various chemistries and morphologies. The method enables the use of ceramics and metals in novel applications where the unique transport and electrochemical properties offered by minimal surface structures may be exploited.

    8. Double Carbon Coating of LiFePO4 as High Rate Electrode for Rechargeable Lithium Batteries (pages 4842–4845)

      Sung Woo Oh, Seung-Taek Myung, Seung-Min Oh, Kyu Hwan Oh, Khalil Amine, Bruno Scrosati and Yang-Kook Sun

      Article first published online: 11 NOV 2010 | DOI: 10.1002/adma.200904027

      Thumbnail image of graphical abstract

      Micrometer-size LiFePO4 spheres with homogeneous double carbon coating layers have been prepared as potential electrode materials for battery applications. The double carbon-coated LiFePO4 electrodes in a lithium-ion cell exhibited discharge capacities of the order of 160 mAh g−1 and 115 mAh g−1 at 25 °C under 0.1 C-rate and 10 C-rate, respectively.

    9. An Electro-optical Device from a Biofilm Structure Created by Bacterial Activity (pages 4846–4850)

      Erick Castellón, Max Chavarría, Víctor de Lorenzo, Marcos Zayat and David Levy

      Article first published online: 17 AUG 2010 | DOI: 10.1002/adma.201001986

      Thumbnail image of graphical abstract

      A reversible electro-optical light switching device is prepared by the combination of a biofilm created by a bacterial cell culture and its combination with a liquid crystal (LC). The macroporous structure of the biofilms, where the LC molecules are allocated, produces the required tridimensional orientational arrangement of the LC molecules that results in an opaque device. Upon application of a minor electric field, the LC molecules are reoriented and the device becomes transparent.

    10. Nano-Layered Microneedles for Transcutaneous Delivery of Polymer Nanoparticles and Plasmid DNA (pages 4851–4856)

      Peter C. DeMuth, Xingfang Su, Raymond E. Samuel, Paula T. Hammond and Darrell J. Irvine

      Article first published online: 21 SEP 2010 | DOI: 10.1002/adma.201001525

      Thumbnail image of graphical abstract

      Multilayer-coated microneedles achieve transcutaneous delivery of plasmid DNA to the viable epidermis. Cy3-labeled plasmid DNA encoding luciferase (yellow) is deposited on biodegradable microneedle arrays through multilayer self-assembly and then delivered to the skin by microneedle application to achieve colocalization with Langerhans dendritic cells (MHC II-GFP–green).

    11. The Topographic Effect of Zinc Oxide Nanoflowers on Osteoblast Growth and Osseointegration (pages 4857–4861)

      Jung Kyu Park, Yong-Jin Kim, Junseok Yeom, Ju Hyeong Jeon, Gyu-Chul Yi, Jung Ho Je and Sei Kwang Hahn

      Article first published online: 9 SEP 2010 | DOI: 10.1002/adma.201002255

      Thumbnail image of graphical abstract

      ZnO nanoflowers prepared by a solution-based hydrothermal growth method result in effective osteoblast growth with higher DNA content, ALP activity, and adhesion strength than those on ZnO film. Furthermore, ZnO nanoflowers are tightly osseointegrated into the regenerated bones. The approach for fabricating nanoflower structures on biomaterial surfaces can be successfully exploited for various bone tissue engineering applications.

    12. A High Mobility P-Type DPP-Thieno[3,2-b]thiophene Copolymer for Organic Thin-Film Transistors (pages 4862–4866)

      Yuning Li, Samarendra P. Singh and Prashant Sonar

      Article first published online: 20 AUG 2010 | DOI: 10.1002/adma.201002313

      Thumbnail image of graphical abstract

      A copolymer comprising 1,4-diketopyrrolo[3,4-c]pyrrole (DPP) and thieno[3,2-b]thiophene moieties, PDBT-co-TT, shows high hole mobility of up to 0.94 cm2 V−1 s−1 in organic thin-film transistors. The strong intermolecular interactions originated from π-π stacking and donor-acceptor interaction lead to the formation of interconnected polymer networks having an ordered lamellar structure, which have established highly efficient pathways for charge carrier transport.

    13. Ultrasensitive Detection of DNA Molecules with High On/Off Single-Walled Carbon Nanotube Network (pages 4867–4871)

      Dongliang Fu, Haruya Okimoto, Chun Wei Lee, Taishi Takenobu, Yoshihiro Iwasa, Hiromichi Kataura and Lain-Jong Li

      Article first published online: 31 AUG 2010 | DOI: 10.1002/adma.201002305

      Thumbnail image of graphical abstract

      Semiconducting networks were found to be extremely sensitive to charges, which promises the electrical detection of ultralow concentrations of DNA (down to 0.1 fM, ∼100 DNA molecules).

    14. Thin Film Field-Effect Phototransistors from Bandgap-Tunable, Solution-Processed, Few-Layer Reduced Graphene Oxide Films (pages 4872–4876)

      Haixin Chang, Zhenhua Sun, Qinghong Yuan, Feng Ding, Xiaoming Tao, Feng Yan and Zijian Zheng

      Article first published online: 8 SEP 2010 | DOI: 10.1002/adma.201002229

      Thumbnail image of graphical abstract

      Thin film field-effect phototransistors (FETs) can be developed from bandgap-tunable, solution-processed, few-layer reduced graphene oxide (FRGO) films. Large-area FRGO films with tunable bandgaps ranging from 2.2 eV to 0.5 eV can be achieved readily by solution-processing technique such as spin-coating. The electronic and optoelectronic properties of FRGO FETs are found to be closely related to their bandgap energy. The resulting phototransistor has great application potential in the field of photodetection.

    15. Hydrogen Sensing Using Pd-Functionalized Multi-Layer Graphene Nanoribbon Networks (pages 4877–4880)

      Jason L. Johnson, Ashkan Behnam, S. J. Pearton and Ant Ural

      Article first published online: 27 AUG 2010 | DOI: 10.1002/adma.201001798

      Thumbnail image of graphical abstract

      Hydrogen sensors from Pd-functionalized multi-layer graphene nanoribbon networks are fabricated. The fabrication method of these networks is simple, low cost, and scalable, and their high specific surface area facilitates efficient functionalization and gas adsorption. These networks show high sensitivity to hydrogen at parts-per-million concentration levels at room temperature with a fast response and recovery time.

    16. Energetic Disorder in Higher Fullerene Adducts: A Quantum Chemical and Voltammetric Study (pages 4881–4884)

      Jarvist Moore Frost, Mark Anton Faist and Jenny Nelson

      Article first published online: 27 SEP 2010 | DOI: 10.1002/adma.201002189

      Thumbnail image of graphical abstract

      Predicting Energetic Disorder: A quantum chemical method is used to calculate the LUMO energies of all possible isomers of the bis and tris adducts of the fullerene, [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). The calculated energy level distributions agree well with the observed mean and spread of LUMO energies as determined using solution differential pulse voltammetry (DPV). We propose this method as a powerful tool for the design and functional optimisation of novel fullerenes, as well as other classes of pi-conjugated molecules with multiple isomers.

    17. A Silica Nanorattle with a Mesoporous Shell: An Ideal Nanoreactor for the Preparation of Tunable Gold Cores (pages 4885–4889)

      Longfei Tan, Dong Chen, Huiyu Liu and Fangqiong Tang

      Article first published online: 24 SEP 2010 | DOI: 10.1002/adma.201002277

      Thumbnail image of graphical abstract

      Using silica nanorattles filled with N-[3-(trimethoxysilyl) propyl] ethylenediamine as nanoreactors, size-tunable gold cores are fabricated inside the silica nanorattles using a facile, efficient, and large-scale method.

    18. Enhanced Light Out-Coupling of Organic Light-Emitting Diodes: Spontaneously Formed Nanofacet-Structured MgO as a Refractive Index Modulation Layer (pages 4890–4894)

      Kihyon Hong, Hak Ki Yu, Ilhwan Lee, Kisoo Kim, Sungjun Kim and Jong-Lam Lee

      Article first published online: 13 SEP 2010 | DOI: 10.1002/adma.201002028

      Thumbnail image of graphical abstract

      The light out-coupling efficiency of OLEDs is enhanced by the use of a refractive index modulation layer (RIML) with MgO nanofacet structure (see figure) that can be formed without an additional lithographic or patterning processes. Increases in luminance and power efficiency of up to 19% and 34.7%, respectively, are demonstrated. Low out-coupling efficiency is one of the main limitations to highly efficient OLEDs, so overcoming it would allow substantial improvements.

    19. Tensile Tests on Individual Multi-Walled Boron Nitride Nanotubes (pages 4895–4899)

      Xianlong Wei, Ming-Sheng Wang, Yoshio Bando and Dmitri Golberg

      Article first published online: 20 AUG 2010 | DOI: 10.1002/adma.201001829

      Thumbnail image of graphical abstract

      Tensile loading and pullouts of individual multi-walled BNNTs were studied for the first time by in-situ tests in the integrated HRTEM-AFM setup. Most important mechanical parameters, such as the ultimate tensile strength and strain, maximum sustainable load and the Young’s modulus of tubes, were measured. Under parallel HRTEM observations the measured mechanical parameters were correlated to experimental conditions and tube structures.

    20. Near-Infrared Inorganic/Organic Optical Upconverter with an External Power Efficiency of >100% (pages 4900–4904)

      Jun Chen, Dayan Ban, Michael G. Helander, Zheng-Hong Lu and Philip Poole

      Article first published online: 23 AUG 2010 | DOI: 10.1002/adma.201001946

      Thumbnail image of graphical abstract

      A near-infrared (1.5 μm) to visible light (green) electro-optical upconverter with amplified power gain has been designed and demonstrated. The device was fabricated by direct tandem integration of an organic light emitting diode with an inorganic InGaAs/InP heterojunction phototransistor. An overall external upconversion power efficiency of 155% was measured at room temperature, demonstrating the utility of hybrid organic/inorganic semiconductor systems.

    21. Controllable Self-Assembly of n-Type Semiconductors to Microtubes and Highly Conductive Ultralong Microwires (pages 4905–4909)

      Xiaoyue Mu, Weifeng Song, Yu Zhang, Kaiqi Ye, Hongyu Zhang and Yue Wang

      Article first published online: 5 OCT 2010 | DOI: 10.1002/adma.201002259

      Thumbnail image of graphical abstract

      Two organic n-type semiconducting compounds have been employed to controllably synthesize 1D microtubes or ultralong microwires via a simple solution process. Excellent electrical conductivity based on the ultralong microwires with the use of the interdigitated electrodes as well as high electron mobility of the microwires measured in ambient conditions by organic field effect transister (OFET) devices were achieved.

SEARCH

SEARCH BY CITATION