Advanced Functional Materials

Cover image for Vol. 17 Issue 11

July, 2007

Volume 17, Issue 11

Pages 1721–1858

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Full Papers
    5. Index
    1. Cover Picture: Preparation of Rectangular WO3·H2O Nanotubes Under Mild Conditions (Adv. Funct. Mater. 11/2007)

      Z. Wang, S. Zhou and L. Wu

      Version of Record online: 12 JUL 2007 | DOI: 10.1002/adfm.200790037

      Thumbnail image of graphical abstract

      The preparation of rectangular WO3·H2O nanotubes (see figure and cover) with the aid of intercalated polyaniline is reported. Not only are these nanotubes made under relatively mild conditions, but they also have a rectangular cross-section morphology. The reciprocal magnetic susceptibility of the nanotubes rapidly decreases from positive to negative at 90 K, which means that they could potentially be used in electromagnetic devices.

  2. Contents

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Full Papers
    5. Index
  3. Full Papers

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Full Papers
    5. Index
    1. A New Route to Large-Scale Synthesis of Silicon Nanowires in Ultrahigh Vacuum (pages 1729–1734)

      X. Xu, Y. Wang, Z. Liu and R. Zhao

      Version of Record online: 30 MAY 2007 | DOI: 10.1002/adfm.200600658

      Thumbnail image of graphical abstract

      Electron-beam evaporation is described as a novel route to the large-scale synthesis of silicon nanowires. The nanowires are formed in ultrahigh vacuum through a disproportionation reaction of SiO intermediates, and they predominantly grow along a new [221] direction (see figure). This work suggests a new route to producing desirable 1D nanomaterials with high purity.

    2. Optical Tuning of the Reflection of Cholesterics Doped with Azobenzene Liquid Crystals (pages 1735–1742)

      U. A. Hrozhyk, S. V. Serak, N. V. Tabiryan and T. J. Bunning

      Version of Record online: 29 JUN 2007 | DOI: 10.1002/adfm.200600776

      Thumbnail image of graphical abstract

      Doping cholesteric liquid crystals with azobenzene liquid crystals possessing large mesophase ranges is demonstrated as a promising approach to impart large, fast, and reversible dynamic, photosensitive features in thin films formed using these mixtures (see figure). Large shifts in the reflection wavelength with low laser power are demonstrated. These photosensitive features are demonstrated using both continuous wave and nanosecond laser beams.

    3. Templated Synthesis of Porous Capsules with a Controllable Surface Morphology and their Application as Gas Sensors (pages 1743–1749)

      W. S. Choi, H. Y. Koo, Z. Zhongbin, Y. Li and D.-Y. Kim

      Version of Record online: 8 JUN 2007 | DOI: 10.1002/adfm.200601002

      Thumbnail image of graphical abstract

      A novel templated synthesis method is developed for the synthesis of porous hematite, silica, and composite hematite–silica capsules, as schematically depicted in the figure. The surface morphology and size of the capsules can be tuned by adjusting the polyelectrolyte templates used during synthesis. The hematite capsules are used for the detection of ethanol vapor.

    4. New Organic Nonlinear Optical Polyene Crystals and Their Unusual Phase Transitions (pages 1750–1756)

      O-P. Kwon, S.-J. Kwon, M. Jazbinsek, A. Choubey, V. Gramlich and P. Günter

      Version of Record online: 29 JUN 2007 | DOI: 10.1002/adfm.200600494

      Thumbnail image of graphical abstract

      Nonlinear optical polyene crystals containing pyrrolidine donors (see figure) exhibit a large macroscopic second-order nonlinearity and unusual reversible or irreversible thermally induced phase transitions, changing the crystal symmetry from higher symmetry to lower symmetry with increasing temperature.

    5. Host Selection and Configuration Design of Electrophosphorescent Devices (pages 1757–1764)

      H. Xia, M. Li, D. Lu, C. B. Zhang, W. J. Xie, X. D. Liu, B. Yang and Y. G. Ma

      Version of Record online: 20 JUN 2007 | DOI: 10.1002/adfm.200600882

      Thumbnail image of graphical abstract

      The charge-trapping ability of phosphorescent molecules is reflected by their electrochemical behavior. The electrochemical properties of these molecules can, thus, be used to design efficient electroluminescent (EL) devices by choosing the right host materials and device structure. For instance, using [Ru(4,7-Ph2-phen)3]2+ as a dopant in a p-type host can effectively increase the efficiency of EL devices, while the light emission is inefficient when using an n-type host (see figure).

    6. Towards a Fundamental Understanding of the Improved Electrochemical Performance of Silicon–Carbon Composites (pages 1765–1774)

      J. Saint, M. Morcrette, D. Larcher, L. Laffont, S. Beattie, J.-P. Pérès, D. Talaga, M. Couzi and J.-M. Tarascon

      Version of Record online: 20 JUN 2007 | DOI: 10.1002/adfm.200600937

      Thumbnail image of graphical abstract

      Si particles homogenously dispersed in a dense and nonporous carbon matrix are prepared by the pyrolysis of intimate blends of Si particles and poly(vinyl chloride). A pronounced improvement in retention capacity is achieved for these composites as compared to bare Si powders (see figure). The improved performance is related to the dense nature of the carbon matrix, the compressive stress it generates on the Si particles, and the resulting stable electrical connectivity it maintains along cycling.

    7. Design of Dispersants for the Dispersion of Carbon Nanotubes in an Organic Solvent (pages 1775–1783)

      K. K. Kim, S.-M. Yoon, J.-Y. Choi, J. Lee, B.-K. Kim, J. M. Kim, J.-H. Lee, U. Paik, M. H. Park, C. W. Yang, K. H. An, Y. Chung and Y. H. Lee

      Version of Record online: 20 JUN 2007 | DOI: 10.1002/adfm.200600915

      Thumbnail image of graphical abstract

      Oligomeric dispersants based on a 3-hexylthiophene monomer are used to disperse single-walled carbon nanotubes (SWCNTs) in an organic solvent. The number of repeat units, the regioregularity of the head groups, and the head-to-tail ratios (see figure) are varied to enhance the dispersion of SWCNTs. SWCNTs combined with thiophene oligomers remain homogeneous in solution while SWCNTs in solution without added dispersant aggregate over time (see figure, right panel).

    8. Controlling the Structure and Morphology of Monodisperse Polystyrene/Polyaniline Composite Particles (pages 1784–1789)

      Q. Wu, Z. Wang and G. Xue

      Version of Record online: 20 JUN 2007 | DOI: 10.1002/adfm.200700170

      Thumbnail image of graphical abstract

      Monodisperse core/shell polystyrene/polyaniline (PS/PANi) composite particles (see figure) are obtained by a process involving swelling, diffusion, and then polymerization at the interface. Control over the structure and morphology of the composite particles is achieved through this novel method by simply changing the aniline/PS weight ratio or the rate of addition of the doping agent.

    9. Preparation of Rectangular WO3·H2O Nanotubes Under Mild Conditions (pages 1790–1794)

      Z. Wang, S. Zhou and L. Wu

      Version of Record online: 26 JUN 2007 | DOI: 10.1002/adfm.200601195

      Thumbnail image of graphical abstract

      The preparation of rectangular WO3·H2O nanotubes (see figure and cover) with the aid of intercalated polyaniline is reported. Not only are these nanotubes made under relatively mild conditions, but they also have a rectangular cross-section morphology. The reciprocal magnetic susceptibility of the nanotubes rapidly decreases from positive to negative at 90 K, which means that they could potentially be used in electromagnetic devices.

    10. Photoresponse Properties of CdSe Single-Nanoribbon Photodetectors (pages 1795–1800)

      Y. Jiang, W. J. Zhang, J. S. Jie, X. M. Meng, X. Fan and S.-T. Lee

      Version of Record online: 29 JUN 2007 | DOI: 10.1002/adfm.200600351

      Thumbnail image of graphical abstract

      Nano-photodetectors are fabricated using individual CdSe nanoribbons (see figure). The single-nanoribbon devices show high sensitivity towards excitation wavelength and perform with excellent stability, reproducibility, and high response speed. Gas absorption and surface defects are demonstrated to influence the photoresponse properties of CdSe nanoribbons significantly.

    11. Synthesis and Characterization of Chromium-Doped Mesoporous Tungsten Oxide for Gas Sensing Applications (pages 1801–1806)

      E. Rossinyol, A. Prim, E. Pellicer, J. Arbiol, F. Hernández-Ramírez, F. Peiró, A. Cornet, J. R. Morante, L. A. Solovyov, B. Tian, T. Bo and D. Zhao

      Version of Record online: 20 JUN 2007 | DOI: 10.1002/adfm.200600722

      Thumbnail image of graphical abstract

      Detection of NO2 at concentrations in the ppb range using mesoporous tungsten oxides is described. WO3 materials have been synthesized from SBA-15 and KIT-6 silica templates (see figure). Influence of mesostructure type on gas sensing properties is shown and discussed. Addition of chromium to the WO3 matrix improves both sensor response and response time.

    12. Polymer Light-Emitting Electrochemical Cells: Doping Concentration, Emission-Zone Position, and Turn-On Time (pages 1807–1813)

      J.-H. Shin, N. D. Robinson, S. Xiao and L. Edman

      Version of Record online: 8 JUN 2007 | DOI: 10.1002/adfm.200600984

      Thumbnail image of graphical abstract

      Light-emitting electrochemical cells comprising large (K or Rb) cations instead of the conventional smaller Li cations exhibit a shorter turn-on time and a more centered emission zone (see figure). The centered emission zone is a direct consequence of a decreased doping concentration in the n-doped region, while the shorter turn-on time is a reflection of an increased ionic conductivity.

    13. Hybrid ZnO–Dye Hollow Spheres with New Optical Properties by a Self-Assembly Process Based on Evans Blue Dye and Cetyltrimethylammonium Bromide (pages 1814–1820)

      H.-P. Cong and S.-H. Yu

      Version of Record online: 12 JUN 2007 | DOI: 10.1002/adfm.200601082

      Thumbnail image of graphical abstract

      Hybrid ZnO–dye hollow spheres composed of well-aligned nanorods can be architecturally synthesized by taking advantage of the cooperative effect of Evans blue and cetyltrimethylammonium bromide as soft templates under mild refluxing conditions (see figure). This approach can be used as a novel and effective tool for controlling the synthesis of organic–inorganic hybrid materials with structural complexities to afford new properties.

    14. Surface Imprinting in Layer-by-Layer Nanostructured Films (pages 1821–1827)

      F. Shi, Z. Liu, G.-L. Wu, M. Zhang, H. Chen, Z. Q. Wang, X. Zhang and I. Willner

      Version of Record online: 20 JUN 2007 | DOI: 10.1002/adfm.200700267

      Thumbnail image of graphical abstract

      An approach for the generation of stable molecularly imprinted sites in polymeric films has been developed by combining the layer-by-layer technique and photochemical crosslinking of the layered structure (see figure). The imprinted films show high reproducibility, and rapid loading and unloading of imprinted sites by the imprinted molecules. Moreover, the films show a higher affinity for template molecules.

    15. The Large Electrochemical Capacitance of Microporous Doped Carbon Obtained by Using a Zeolite Template (pages 1828–1836)

      C. O. Ania, V. Khomenko, E. Raymundo-Piñero, J. B. Parra and F. Béguin

      Version of Record online: 18 JUN 2007 | DOI: 10.1002/adfm.200600961

      Thumbnail image of graphical abstract

      Ordered microporous carbon material doped with nitrogen is synthesized by using a nanocasting process using acrylonitrile and propylene as precursors and Na–Y zeolite as a scaffold. The material displayed large gravimetric capacitance (340 F g–1) in an aqueous medium, and showed good cycleability, beyond 10 000 cycles. The figure shows pore volume as a function of pore size in the templated carbon compared to that in commercial activated carbon.

    16. A Smart Supramolecular Hydrogel Exhibiting pH-Modulated Viscoelastic Properties (pages 1837–1843)

      N. E. Shi, H. Dong, G. Yin, Z. Xu and S. H. Li

      Version of Record online: 29 JUN 2007 | DOI: 10.1002/adfm.200600857

      Thumbnail image of graphical abstract

      The macroscopic viscoelastic property of a physical hydrogel is reversibly modulated by tuning the microscopic hydrogen-bonding interactions with pH. The yield stress of the hydrogel is greatly enhanced from 10 to 769 Pa by changing the pH value from 7.0 to 5.0 (see figure).

    17. Whelk-like Helixes of Polypyrrole Synthesized by Electropolymerization (pages 1844–1848)

      G. Chen, Z. Y. Wang, D. G. Xia, L. Zhang, R. Hui and J. J. Zhang

      Version of Record online: 26 JUN 2007 | DOI: 10.1002/adfm.200600828

      Thumbnail image of graphical abstract

      Whelk-like spiral helixes of polypyrrole were synthesized by an electropolymerization process. High-resolution SEM (see figure) clearly shows the whorls around the polypyrrole whelk body; these whorls have ordered periodic nanostructures on their surface. A spiral growth mechanism is proposed. The whelk-like polypyrrole layer shows high thermal stability, super-hydrophilicity, and strong electrocatalytic activity towards the oxidation of ascorbic acid.

    18. Mesoporous Separation Membranes of Polymer-Coated Copper Hydroxide Nanostrands (pages 1849–1855)

      X. S. Peng, J. Jin and I. Ichinose

      Version of Record online: 8 JUN 2007 | DOI: 10.1002/adfm.200600911

      Thumbnail image of graphical abstract

      Thin free-standing films with mesoscopic pores prepared from copper hydroxide nanostrands (see figure) have been uniformly coated with polypyrrole or polyaniline. The films are stable for pressure loadings up to at least 90 kPa, and they show size-selective permeation of proteins, retaining extremely high filtration rates for water.

  4. Index

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Full Papers
    5. Index

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