Advanced Materials

Cover image for Vol. 18 Issue 18

September, 2006

Volume 18, Issue 18

Pages 2343–2490

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Communications
    6. Book Review
    7. Index
    1. Cover Picture: A Single Polymer Nanowire Photodetector (Adv. Mater. 18/2006)

      G. A. O'Brien, A. J. Quinn, D. A. Tanner and G. Redmond

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200690073

      Solution-assisted template wetting has been successfully applied to a high-yield controlled synthesis of poly[9,9-dioctylfluorenyl-2,7-diyl)-co-[bithiophene)] nanowires. Photoconductivity measurements (see figure and cover) yield single-nanowire device responsivities of ca. 0.4 mA W–1 and external quantum efficiencies of ca. 0.1 % under monochromatic illumination, comparable with single-inorganic-nanowire devices. These results demonstrate the promise of these 1D polymer nanostructures as subwavelength photodetectors.

  2. Inside Front Cover

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Communications
    6. Book Review
    7. Index
    1. Inside Front Cover: Curling Colloidal Photonic Crystals (Adv. Mater. 18/2006)

      E. Vekris, G. A. Ozin and V. Kitaev

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200690074

      Photonic crystals with tunable curvature based on inverse opals are demonstrated (see figure and inside cover). The curvature is tuned through the controlled formation and hydrolysis of an overlayer upon infiltration of templated colloidal crystals using sol–gel precursors. The optical properties of individual curved inverse zirconia opal microstructures are studied by means of micro-optical spectroscopy.

  3. Contents

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Communications
    6. Book Review
    7. Index
    1. Contents: Adv. Mater. 18/2006 (pages 2343–2352)

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200690071

  4. Communications

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Communications
    6. Book Review
    7. Index
    1. Tubular Nanostructures from Degradable Core–Shell Cylinder Microstructures in Chiral Diblock Copolymers (pages 2355–2358)

      R.-M. Ho, C.-K. Chen, Y.-W. Chiang, B.-T. Ko and C.-C. Lin

      Article first published online: 22 AUG 2006 | DOI: 10.1002/adma.200601135

      Thumbnail image of graphical abstract

      A core–shell cylinder phase is obtained from the self assembly of chiral diblock copolymers, polystyrene-b-poly(L-lactide) (PS–PLLA) with PLLA-rich fractions. After the self-assembly of the polymer chains, scrolling of the helical microdomains results in core–shell cylinder microstructures (see figure). The microstructures are then hydrolyzed to give polymeric nanotubes with potential applications in drug delivery and as nanoreactors.

    2. Dynamically Reconfigurable Polymer Films: Impact on Nanomotion (pages 2359–2362)

      S. Santer, A. Kopyshev, J. Donges, H.-K. Yang and J. Rühe

      Article first published online: 29 AUG 2006 | DOI: 10.1002/adma.200601270

      Thumbnail image of graphical abstract

      Polymer brushes comprising two different chemistries can induce motion of adsorbed nanometer-scale objects. Topographical variations of the brushes occurring along with nanometer phase separation after exposure to selective solvents result in variations of surface forces between the substrate and the adsorbed object, inducing its motion (see figure).

    3. The Microstructure of Biogenic Calcite: A View by High-Resolution Synchrotron Powder Diffraction (pages 2363–2368)

      B. Pokroy, A. Fitch and E. Zolotoyabko

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200600714

      Thumbnail image of graphical abstract

      Biogenic calcite obtained from different mollusk shells is subjected to heat treatments at elevated temperatures and structurally analyzed by high-resolution synchrotron X-ray powder diffraction. Remarkable broadening of diffraction peaks in samples annealed at temperatures above 200 °C is observed (see figure), indicating heat-induced degradation of intra-crystalline proteins occluded in the mineral lattice during biomineralization.

    4. Organic Crystals with Tunable Emission Colors Based on a Single Organic Molecule and Different Molecular Packing Structures (pages 2369–2372)

      H. Y. Zhang, Z. L. Zhang, K. Q. Ye, J. Y. Zhang and Y. Wang

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200600704

      Thumbnail image of graphical abstract

      3(5)-(9-Anthryl)pyrazole (ANP) can be used as a building block to construct different luminescent single crystals based on hydrogen bonding and π…π stacking interactions. Five types of single crystals—obtained by controlling the molecular assembly structures—that exhibit blue, blue-green, and green emission can be obtained, two of which are shown in the figure with their corresponding structures.

    5. Biocompatible, Hydrophilic, Supramolecular Carbon Nanoparticles for Cell Delivery (pages 2373–2378)

      A. Yan, B. W. Lau, B. S. Weissman, I. Külaots, N. Y. C. Yang, A. B. Kane and R. H. Hurt

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200600838

      Thumbnail image of graphical abstract

      Liquid-crystal self-assembly is used to fabricate carbon nanoparticles specially suited for cell-delivery applications (see figure). The nanoparticles possess high-activity surfaces for easy functionalization and aqueous dispersion, and are shown to be rapidly internalized by mesothelial cells, wherein they show no measurable toxicity relative to crystalline silica used as a positive control.

    6. A Single Polymer Nanowire Photodetector (pages 2379–2383)

      G. A. O'Brien, A. J. Quinn, D. A. Tanner and G. Redmond

      Article first published online: 29 AUG 2006 | DOI: 10.1002/adma.200601012

      Thumbnail image of graphical abstract

      Solution-assisted template wetting has been successfully applied to a high-yield controlled synthesis of poly[9,9-dioctylfluorenyl-2,7-diyl)-co-[bithiophene)] nanowires. Photoconductivity measurements (see figure and cover) yield single-nanowire device responsivities of ca. 0.4 mA W–1 and external quantum efficiencies of ca. 0.1 % under monochromatic illumination, comparable with single-inorganic-nanowire devices. These results demonstrate the promise of these 1D polymer nanostructures as subwavelength photodetectors.

    7. Preparation of Sub-micrometer Copper Fibers via Electrospinning (pages 2384–2386)

      M. Bognitzki, M. Becker, M. Graeser, W. Massa, J. H. Wendorff, A. Schaper, D. Weber, A. Beyer, A. Gölzhäuser and A. Greiner

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200600103

      Thumbnail image of graphical abstract

      Sub-micrometer length copper fibers are obtained via polymer supported electrospinning and subsequent thermal treatment. The copper nature of the fibers is confirmed by using energy- dispersive X-ray analysis and wide- angle X-ray analysis (see figure). The copper fibers show metallic conductivity as confirmed by conductance measurements in a low-energy electron point source microscope.

    8. DNA Designer Defects in Photonic Crystals: Optically Monitored Biochemistry (pages 2387–2391)

      F. Fleischhaker, A. C. Arsenault, F. C. Peiris, V. Kitaev, I. Manners, R. Zentel and G. A. Ozin

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200600579

      Thumbnail image of graphical abstract

      Biomolecules have been incorporated as designed planar defect layers in colloidal photonic crystals using self- assembly techniques (see figure). Through shifts of the photonic intragap defect mode, for example, DNA conformational changes and the enantioselective intercalation of a chiral anticancer drug can be optically monitored. This newfound capability for optically monitoring biochemistry bodes well for the development of a new generation of simple on-the-spot color readout biosensors.

    9. Tracing Memory in Polycrystalline Ferromagnetic Shape-Memory Alloys (pages 2392–2396)

      Y.-D. Wang, Y. Ren, H. Li, H. Choo, M. L. Benson, D. W. Brown, P. K. Liaw, L. Zuo, G. Wang, D. E. Brown and E. E. Alp

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200600480

      Thumbnail image of graphical abstract

      In situ high-energy X-ray diffraction experiments reveal the influence of various microstresses and grain orientations on the memory effect in polycrystalline Ni2MnGa ferromagnetic shape-memory alloys during phase transformation (see figure). The “memory” of grain orientation and intergranular stress is evident; however, the microscale “memory” is degraded due to the existence of the intragranular stress.

    10. Multifunctional, Multilayer, Multiscale: Integrative Synthesis of Complex Macroporous and Mesoporous Thin Films with Spatial Separation of Porosity and Function (pages 2397–2402)

      P. C. Angelomé, M. C. Fuertes and G. J. A. A. Soler-Illia

      Article first published online: 29 AUG 2006 | DOI: 10.1002/adma.200600439

      Thumbnail image of graphical abstract

      Complex multilayered thin-film architectures are fabricated by sequentially stacking mesoporous and macroporous layers with varying structure and properties. A series of deposition–stabilization steps are used to sequentially deposit the component layers of the films in order to obtain interconnected systems with a precise ordering of accessible cavities, as shown in the figure.

    11. New Nano- and Microparticles with a Liquid-Crystal-Like Interior (pages 2403–2406)

      S. Trabelsi, S. Guillot, E. Raspaud, M. Delsanti, D. Langevin and F. Boué

      Article first published online: 28 AUG 2006 | DOI: 10.1002/adma.200600444

      Thumbnail image of graphical abstract

      Mixtures of oppositely charged surfactants and polyelectrolytes yield well- defined monodisperse particles with a liquid-crystal-like interior in aqueous solution, as evidenced by the neutron scattering data shown in the figure. The particle size increases exponentially with the surfactant concentration, linearly with the charge on the polymer backbone, and is independent of the polymer concentration.

    12. Rigid Macroporous Poly(divinylbenzene) Monoliths with a Well-Defined Bicontinuous Morphology Prepared by Living Radical Polymerization (pages 2407–2411)

      K. Kanamori, K. Nakanishi and T. Hanada

      Article first published online: 29 AUG 2006 | DOI: 10.1002/adma.200601026

      Thumbnail image of graphical abstract

      Rigid macroporous poly(divinylbenzene) monoliths with good mechanical and thermal stability and possessing a well-defined bicontinous structure (see figure) are synthesized using living radical polymerization and a polymeric phase separator. The macropore size and volume can be independently tuned by varying the starting compositions of the mixtures. Scale bars represent 20 μm, a–d show increasing polydimethylsiloxane concentration.

    13. High-Contrast Thin-Film Polarizers by Photo-Crosslinking of Smectic Guest–Host Systems (pages 2412–2417)

      E. Peeters, J. Lub, J. A. M. Steenbakkers and D. J. Broer

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200600355

      Thumbnail image of graphical abstract

      High-contrast, thin-film polarizers based on dye-doped reactive liquid crystals (see figure) equal the polarization performance of conventional sheet polarizers at strongly reduced thicknesses. Advantageously, the guest–host polarizers can be patterned and applications are envisioned in liquid-crystal displays.

    14. Self-Assembly and Self-Orientation of Truncated Octahedral Magnetite Nanocrystals (pages 2418–2421)

      R. K. Zheng, H. Gu, B. Xu, K. K. Fung, X. X. Zhang and S. P. Ringer

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200600788

      Thumbnail image of graphical abstract

      Monodisperse magnetite nanoparticles (12 nm) in the shape of Wigner–Seitz crystals self-assemble into a body-centered cubic superlattice (see figure) in which the nanoparticles possess the same crystallographic orientations. Shape plays a critical role in controlling the orientation of the nanoparticles in self-assembly. Both self-assembly and self-orientation of nanoparticles are important for technical applications such as high-density magnetic storage.

    15. Coulomb Blockade Tuned by NO2 Molecules in Nanostructured Silicon (pages 2422–2425)

      S. Borini, L. Boarino and G. Amato

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200600198

      Thumbnail image of graphical abstract

      Electrochemical etching of heavily doped Si can be used as a simple self- assembly technique for the fabrication of Si nanocrystal arrays. The obtained nanostructures exhibit Coulomb- blockade behavior at room temperature, and are very sensitive to the presence of molecules with high electron affinities, such as NO2 (see figure). Tunable gas sensors that work at room temperature can thus be obtained.

    16. Self-Assembled 3D Flowerlike Iron Oxide Nanostructures and Their Application in Water Treatment (pages 2426–2431)

      L.-S. Zhong, J.-S. Hu, H.-P. Liang, A.-M. Cao, W.-G. Song and L.-J. Wan

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200600504

      Thumbnail image of graphical abstract

      An ethylene-glycol-mediated self-assembly process is adopted to synthesize 3D flowerlike nanostructures of iron oxide (see figure) using inexpensive and nontoxic ferric chloride. A two-stage growth process is identified during the morphological evolution of the iron oxide precursor. α-Fe2O3, γ-Fe2O3, and Fe3O4 with the same flowerlike structure are readily obtained from the same precursor but by different calcination procedures. The as-obtained iron oxides show excellent ability to remove various pollutants from water.

    17. Dissolving Behavior and Stability of ZnO Wires in Biofluids: A Study on Biodegradability and Biocompatibility of ZnO Nanostructures (pages 2432–2435)

      J. Zhou, N. S. Xu and Z. L. Wang

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200600200

      Thumbnail image of graphical abstract

      The biodegradability and biocompatibility of ZnO wires in biofluid has been studied by investigating the interaction of the wires with deionized water, ammonia, NaOH solution, and horse blood serum. The results show that ZnO can be dissolved into mineral ions by these liquids within a few hours (see figure) and that ZnO is a bio-safe, nontoxic material for in vivo biosensing and biodetection.

    18. Tuning Nanomaterials' Characteristics by a Miniaturized In-Line Dispersion–Precipitation Method: Application to Hydrotalcite Synthesis (pages 2436–2439)

      S. Abelló and J. Pérez-Ramírez

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200600673

      Thumbnail image of graphical abstract

      The impact of the residence time (τ) in a microreactor on the relative extent of nucleation, crystal growth, and agglomeration processes, leading to remarkable differences in materials characteristics (see figure) by a novel in-line dispersion–precipitation (ILDP) method for the preparation of nanomaterials is reported. The tuning of crystallite size (equation image) and surface area (SBET) is illustrated for Mg–Al hydrotalcites (synthetic clays).

    19. High-Density Energetic Material Hosted in Pure Silica MFI-Type Zeolite Nanocrystals (pages 2440–2443)

      G. Majano, S. Mintova, T. Bein and T. M. Klapötke

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200601109

      Thumbnail image of graphical abstract

      Desensitization of the “green” high-density energetic material Fox-7 inside the pores of pure silica MFI-type nanozeolites (see figure) leads to nonexplosive decomposition about 100 °C above the explosive temperature for the pure substance.

    20. Reversible Formation of Molecular Junctions in 2D Nanoparticle Arrays (pages 2444–2447)

      J. Liao, L. Bernard, M. Langer, C. Schönenberger and M. Calame

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200601001

      Thumbnail image of graphical abstract

      The preparation of molecular junctions networks using self-assembly and microcontact printing of ligand-protected metallic nanoparticles is demonstrated. A subsequent in situ ligand-exchange reaction permits the interlinking of neighboring nanoparticles. The exchange process is shown to be reversible (see figure).

      Corrected by:

      Correction: Reversible Formation of Molecular Junctions in 2D Nanoparticle Arrays

      Vol. 18, Issue 21, 2803, Article first published online: 30 OCT 2006

    21. High-Mobility p-Type Transistor Based on a Spin-Coated Metal Telluride Semiconductor (pages 2448–2452)

      D. B. Mitzi, M. Copel and C. E. Murray

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200600157

      Thumbnail image of graphical abstract

      A crystalline CuInTe2 film is used as the channel layer in a thin-film field-effect transistor (see figure) yielding field-effect mobilities of over 10 cm2 V–1 s–1, which is approximately an order of magnitude better than previous results for spin-coated p-type systems. A novel three-component hydrazine-based solution is employed to achieve spin coating of the CuInTe2 film.

    22. Hydrothermal Growth of Periodic, Single-Crystal ZnO Microrods and Microtunnels (pages 2453–2457)

      J. H. Kim, D. Andeen and F. F. Lange

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200600257

      Thumbnail image of graphical abstract

      The controllable growth of a periodic hexagonal array of ZnO microrods and linear arrays of ZnO microtunnels has been demonstrated using hydrothermal synthesis and channel stamping. ZnO walls (see figure) are formed from a solution containing Zn(NO3)2·6 H2O at pH 10.9 for 24 h at 90 °C. The controlled growth of these ZnO crystals is expected to have great potential for biosensing, optical emission, and ultrasonic imaging applications.

    23. Responsive Polyelectrolyte Gel Membranes (pages 2458–2460)

      I. Tokarev, M. Orlov and S. Minko

      Article first published online: 29 AUG 2006 | DOI: 10.1002/adma.200601288

      Thumbnail image of graphical abstract

      Ultrathin polyelectrolyte gel pH-responsive membranes with sub-micrometer pore size are synthesized on planar substrates. The membranes are thin porous films made of a crosslinked polyelectrolyte that can be easily transferred onto various porous and nonporous substrates for the fabrication of devices with pH-controllable permeability (see figure).

    24. Conjugated Polymer Nanoparticles via Intramolecular Crosslinking of Dendrimeric Precursors (pages 2461–2465)

      P. Taranekar, J.-Y. Park, D. Patton, T. Fulghum, G. J. Ramon and R. Advincula

      Article first published online: 29 AUG 2006 | DOI: 10.1002/adma.200600491

      Thumbnail image of graphical abstract

      Intramolecular crosslinking of benzylether-based dendrimers functionalized with electroactive carbazole peripheral groups is performed using both chemical and electrochemical methods. The changes in structure, rigidity, size, and conformation of the uncrosslinked and crosslinked precursor dendrimer nanoparticles are compared and modeled (see figure).

    25. Organic Heteroepitaxy: p-Sexiphenyl on Uniaxially Oriented α-Sexithiophene (pages 2466–2470)

      M. Oehzelt, G. Koller, J. Ivanco, S. Berkebile, T. Haber, R. Resel, F. P. Netzer and M. G. Ramsey

      Article first published online: 28 AUG 2006 | DOI: 10.1002/adma.200600476

      Thumbnail image of graphical abstract

      Organic–organic heteroepitaxy using two rodlike aromatic molecules shows that p-sexiphenyl aligns predominantly parallel to an underlying uniaxially oriented α-sexithiophene film (see figure) although there is no lattice match of the two layers. The structure of both layers is determined and the results suggest that a simple transfer of the well-established models of inorganic epitaxy cannot explain the heterostructures formed here.

    26. Nanorice and Nanospears from Polymer Nanospheres (pages 2471–2475)

      D. Srivastava and I. Lee

      Article first published online: 22 AUG 2006 | DOI: 10.1002/adma.200601123

      Thumbnail image of graphical abstract

      Nanostructured particles like nanorice and nanospears (i.e., tapered nanorods, see figure) are produced using polymer nanospheres and ordered porous templates. The ordered cylindrical nanopores of anodized alumina membranes are filled with spherical polymer nanoparticles by solvent-assisted nanoinjection. Then, the membranes are heated in an oven above the glass-transition temperature of the polymer.

    27. Signature of Intrinsic High-Temperature Ferromagnetism in Cobalt-Doped Zinc Oxide Nanocrystals (pages 2476–2480)

      X. F. Wang, J. B. Xu, B. Zhang, H. G. Yu, J. Wang, X. Zhang, J. G. Yu and Q. Li

      Article first published online: 28 AUG 2006 | DOI: 10.1002/adma.200600396

      Thumbnail image of graphical abstract

      Nanocrystalline Zn1–xCoxO (x = 0.020, 0.056, and 0.098) powders exhibit intrinsic high-temperature ferromagnetism, as suggested by the well-defined hysteresis loops shown in the figure. The origin of this ferromagnetism is thought to be electron transfer from host Zn 4s[UPWARDS ARROW] states to unfilled dopant Co 3d[DOWNWARDS ARROW] states (shown in the inset to the figure), which leads to the formation of a spin-split impurity band at the Fermi level in the gap.

    28. Curling Colloidal Photonic Crystals (pages 2481–2485)

      E. Vekris, G. A. Ozin and V. Kitaev

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200600763

      Thumbnail image of graphical abstract

      Photonic crystals with tunable curvature based on inverse opals are demonstrated (see figure and inside cover). The curvature is tuned through the controlled formation and hydrolysis of an overlayer upon infiltration of templated colloidal crystals using sol–gel precursors. The optical properties of individual curved inverse zirconia opal microstructures are studied by means of micro-optical spectroscopy.

  5. Book Review

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

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Communications
    6. Book Review
    7. Index
    1. Author Index and Subject Index Adv. Mater. 18/2006 (pages 2489–2490)

      Article first published online: 12 SEP 2006 | DOI: 10.1002/adma.200690072

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