Advanced Functional Materials

Cover image for Vol. 17 Issue 8

May, 2007

Volume 17, Issue 8

Pages 1215–1430

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Feature Article
    5. Full Papers
    6. Index
    1. Cover Picture: Encapsulation of Water-Immiscible Solvents in Polyglutamate/ Polyelectrolyte Nanocontainers (Adv. Funct. Mater. 8/2007)

      X. Teng, D. G. Shchukin and H. Möhwald

      Article first published online: 15 MAY 2007 | DOI: 10.1002/adfm.200790027

      Encapsulation of hydrophobic materials into a hydrophilic multifunctional shell can be achieved by the creative combination of ultrasound with layer-by-layer assembly (see figure). The obtained nanocontainers feature a hydrophobic core that may contain a variety of water-insoluble drugs and an outer shell that may show controlled permeability and desired multifunctionality.

  2. Contents

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Feature Article
    5. Full Papers
    6. Index
    1. Contents: Adv. Funct. Mater. 8/2007 (pages 1215–1223)

      Article first published online: 15 MAY 2007 | DOI: 10.1002/adfm.200790025

  3. Feature Article

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Feature Article
    5. Full Papers
    6. Index
    1. Mesoporous Silica Nanoparticles for Drug Delivery and Biosensing Applications (pages 1225–1236)

      I. I. Slowing, B. G. Trewyn, S. Giri and V. S.-Y. Lin

      Article first published online: 20 APR 2007 | DOI: 10.1002/adfm.200601191

      Thumbnail image of graphical abstract

      Mesoporous silica nanoparticles (MSNs) with controlled morphology and porosity can be chemically functionalized to serve as intracellular delivery vehicles for the controlled release of drugs and genes (see figure), and for the selective detection of biomolecules. Research progress on the design of functional MSN materials with various mechanisms of controlled release is reviewed.

  4. Full Papers

    1. Top of page
    2. Cover Picture
    3. Contents
    4. Feature Article
    5. Full Papers
    6. Index
    1. Polyarylene Networks via Bergman Cyclopolymerization of Bis-ortho-diynyl Arenes (pages 1237–1246)

      D. W. Smith Jr., H. V. Shah, K. P. U. Perera, M. W. Perpall, D. A. Babb and S. J. Martin

      Article first published online: 18 APR 2007 | DOI: 10.1002/adfm.200600450

      Thumbnail image of graphical abstract

      Bis-ortho-diynyl arene (BODA) monomers (see figure) thermally cyclize and polymerize to form processable photoluminescent oligomers suitable for micro- and nanoscale molding and coating. Further heating to 450 °C yields thermally stable polyarylene networks, and pyrolysis at 900 °C produces high-yield semiconductive glassy carbon.

    2. Photonic Crystals from Ordered Mesoporous Thin-Film Functional Building Blocks (pages 1247–1254)

      M. C. Fuertes, F. J. López-Alcaraz, M. C. Marchi, H. E. Troiani, V. Luca, H. Míguez and G. J. A. A. Soler-Illia

      Article first published online: 28 MAR 2007 | DOI: 10.1002/adfm.200601190

      Thumbnail image of graphical abstract

      Environment-sensitive Bragg reflectors are built using functional mesoporous thin films as building blocks. Tuning of optical properties is achieved by changing the composition/porosity of the slabs or by introducing planar defects. Sorption or capillary condensation of molecules into the pore system results in a 10–40 nm red-shift (see figure). Organic functions added to the pore surface change the response, permitting tailoring of the selectivity towards small-size molecules.

    3. Microporous Metal–Organic Frameworks with High Gas Sorption and Separation Capacity (pages 1255–1262)

      J. Y. Lee, D. H. Olson, L. Pan, T. J. Emge and J. Li

      Article first published online: 3 APR 2007 | DOI: 10.1002/adfm.200600944

      Thumbnail image of graphical abstract

      Microporous metal–organic framework structures [M(bdc)(ted)0.5]·2 DMF· 0.2 H2O (M = Zn (1), Cu (2); H2bdc = 1,4-benzenedicarboxylic acid; ted = triethylenediamine; DMF: N,N-dimethylformamide) exhibit very high gas storage and separation capability for hydrogen and selected hydrocarbons, such as alcohols and dimethylether (DME, see figure). 1 gives the highest sorption values among all metal–organic based porous materials reported to date.

    4. pH-Tunable Endosomolytic Oligomers for Enhanced Nucleic Acid Delivery (pages 1263–1272)

      H. C. Kang and Y. H. Bae

      Article first published online: 12 APR 2007 | DOI: 10.1002/adfm.200601188

      Thumbnail image of graphical abstract

      Oligomeric sulfonamides (OSAs) are explored as a tool for the effective endosomal release of polyplexes or delivery of nucleic acid. The OSAs tested in this study show varying proton-buffering regions and pH-dependent solubility transitions within the endosomal pH range, and are influenced by the pKa value and hydrophobicity of a given sulfonamide group (see figure).

    5. Encapsulation of Water-Immiscible Solvents in Polyglutamate/ Polyelectrolyte Nanocontainers (pages 1273–1278)

      X. Teng, D. G. Shchukin and H. Möhwald

      Article first published online: 20 APR 2007 | DOI: 10.1002/adfm.200601229

      Thumbnail image of graphical abstract

      Encapsulation of hydrophobic materials into a hydrophilic multifunctional shell can be achieved by the creative combination of ultrasound with layer-by-layer assembly (see figure). The obtained nanocontainers feature a hydrophobic core that may contain a variety of water-insoluble drugs and an outer shell that may show controlled permeability and desired multifunctionality.

    6. Solvent-Mediated Plasmon Tuning in a Gold-Nanoparticle–Poly(Ionic Liquid) Composite (pages 1279–1287)

      D. Batra, S. Seifert, L. M. Varela, A. C. Y. Liu and M. A. Firestone

      Article first published online: 18 APR 2007 | DOI: 10.1002/adfm.200600797

      Thumbnail image of graphical abstract

      A gold-nanoparticle-containing poly(ionic liquid) is synthesized in a single step by UV irradiation of a metal-ion-doped, self-assembled ionic liquid gel, 1-decyl-3-vinylimidazolium chloride. Solvent-induced swelling and de-swelling (see figure) is shown to provide control over the internal packing arrangement and hence, optical properties of in situ synthesized metal nanoparticles.

    7. Aligned Protein–Polymer Composite Fibers Enhance Nerve Regeneration: A Potential Tissue-Engineering Platform (pages 1288–1296)

      S. Y. Chew, R. Mi, A. Hoke and K. W. Leong

      Article first published online: 13 APR 2007 | DOI: 10.1002/adfm.200600441

      Thumbnail image of graphical abstract

      Fiber is good for you! Sciatic nerve injury in Sprague–Dawley rats was treated with aligned electrospun glial cell-derived neurotrophic factor (GDNF)-encapsulated poly(ϵ-caprolactone-co-ethyl ethylene phosphate) protein–polymer composite fibers. The figure shows a fiber with longitudinal alignment. Enhanced nerve regeneration was observed across a 15 mm critical defect gap at 3 months post-implantation.

    8. Device Operation of Conjugated Polymer/Zinc Oxide Bulk Heterojunction Solar Cells (pages 1297–1302)

      L. J. A. Koster, W. J. van Strien, W. J. E. Beek and P. W. M. Blom

      Article first published online: 28 MAR 2007 | DOI: 10.1002/adfm.200600371

      Thumbnail image of graphical abstract

      Solar cells based on a conjugated polymer and nanocrystalline zinc oxide are investigated. By measuring the charge-transport properties and modeling the current density–voltage characteristics (see figure), it is found that the performance of these solar cells is limited by the charge-carrier mobilities. A discussion is also given about how to further improve the efficiency.

    9. Hierarchical Shelled ZnO Structures Made of Bunched Nanowire Arrays (pages 1303–1310)

      P. Jiang, J.-J. Zhou, H.-F. Fang, C.-Y. Wang, Z. L. Wang and S.-S. Xie

      Article first published online: 3 APR 2007 | DOI: 10.1002/adfm.200600390

      Thumbnail image of graphical abstract

      Shelled structures that consist of bunched ZnO nanowire arrays (see figure) are grown out of metallic Zn microspheres by using a wet-chemical route in the presence of zincate (ZnO22–) ions. The sizes and morphologies of the bunched ZnO nanowires are well controlled by adjusting the experimental conditions, the most important of which is temperature.

    10. Synthesis of Monodisperse FeAu Nanoparticles with Tunable Magnetic and Optical Properties (pages 1311–1316)

      I-C. Chiang and D.-H. Chen

      Article first published online: 3 APR 2007 | DOI: 10.1002/adfm.200600525

      Thumbnail image of graphical abstract

      Monodisperse FeAu nanoparticles are synthesized by the reduction of gold acetate and the thermal decomposition of iron pentacarbonyl with oleic acid and oleylamine as stabilizers (see figure). The incorporation of Au is shown to result in a structure change from face centered to body centered cubic. The alloys exhibit surface plasmon resonance as well as nearly superparamagnetic properties.

    11. Magnetic and Temperature-Sensitive Release Gels from Supramolecular Polymers (pages 1317–1326)

      W. H. Binder, L. Petraru, T. Roth, P. W. Groh, V. Pálfi, S. Keki and B. Ivan

      Article first published online: 3 APR 2007 | DOI: 10.1002/adfm.200601084

      Thumbnail image of graphical abstract

      Supramolecular gels consisting of trivalent polyisobutylene and bivalent poly(ethylene oxide) are generated. Strong hydrogen bonding interactions serve as a molecular glue, and doping with superparamagnetic nanoparticles provide gels with magnetic properties (see figure) and strong temperature- dependent release profile of included dye molecules.

    12. Organic Tube/Rod Hybrid Nanofibers with Adjustable Segment Lengths by Bidirectional Template Wetting (pages 1327–1332)

      O. Kriha, L. Zhao, E. Pippel, U. Gösele, R. B. Wehrspohn, J. H. Wendorff, M. Steinhart and A. Greiner

      Article first published online: 3 APR 2007 | DOI: 10.1002/adfm.200601021

      Thumbnail image of graphical abstract

      Tube/rod hybrid nanofibers were prepared by bidirectional template wetting. The opposite surfaces of a porous template are sequentially wetted with different polymeric liquids. The exploitation of different wetting mechanisms results in the formation of tubular and solid segments (see figure).

    13. Ferroelectric and Ferromagnetic Behavior of Pb(Zr0.52Ti0.48)O3–Co0.9Zn0.1Fe2O4 Multilayered Thin Films Prepared via Solution Processing (pages 1333–1338)

      H.-C. He, J. Wang, J.-P. Zhou and C.-W. Nan

      Article first published online: 3 APR 2007 | DOI: 10.1002/adfm.200600476

      Thumbnail image of graphical abstract

      Multilayered multiferroic films of Pb(Zr0.52Ti0.48)O3 (PZT) and Co0.9Zn0.1Fe2O4 (CZFO) are prepared on a general Pt/Ti/SiO2/Si substrate via solution processing (see figure). Strong ferroelectric and ferromagnetic responses are simultaneously observed in the multilayered thin films at room temperature. Variations in the layer sequence and volume fractions of the phases allow a detailed examination of the magnetic and electric properties.

    14. Surface-Transfer Doping of Organic Semiconductors Using Functionalized Self-Assembled Monolayers (pages 1339–1344)

      W. Chen, X. Y. Gao, D. C. Qi, S. Chen, Z. K. Chen and A. T. S. Wee

      Article first published online: 3 APR 2007 | DOI: 10.1002/adfm.200601029

      Thumbnail image of graphical abstract

      Modifying a Au(111) substrate with self-assembled monolayers (SAMs) containing aromatic thiols with strong electron-withdrawing trifluoromethyl (CF3) functional groups (see figure) results in significant electron transfer from the active organic layers (copper(II) phthalocyanine; CuPc) to the underlying CF3-SAM near the interface. Electron transfer at the CuPc/CF3-SAM interface leads to an electron accumulation layer in CF3-SAM and a depletion layer in CuPc, thereby achieving p-type doping of CuPc layers close to the interface.

    15. ZnO Nanotetrapods: Controlled Vapor-Phase Synthesis and Application for Humidity Sensing (pages 1345–1352)

      Y. Qiu and S. Yang

      Article first published online: 12 APR 2007 | DOI: 10.1002/adfm.200601128

      Thumbnail image of graphical abstract

      The controlled synthesis of ZnO nanotetrapods (see the SEM image in the figure) is investigated by combining metal-vapor transport, oxidative nucleation/growth, fast-flow quenching, and water-assisted cleaning. The technique developed makes possible the fabrication of ZnO nanotetrapods with different morphologies and arm diameters. Photoluminescence studies indicate a higher level of oxygen vacancies for smaller ZnO nanotetrapods.

    16. One-Step Synthesis of Ru(2,2′-Bipyridine)3Cl2-Immobilized Silica Nanoparticles for Use in Electrogenerated Chemiluminescence Detection (pages 1353–1358)

      L. Qian and X.-R. Yang

      Article first published online: 12 APR 2007 | DOI: 10.1002/adfm.200600253

      Thumbnail image of graphical abstract

      One-step synthesis of Ru(bpy)3Cl2- immobilized silica nanoparticles (bpy = 2,2′-bipyridine; see figure) for use in electrogenerated-chemiluminescence (ECL) detection is reported. For ECL detection, Au-colloid-modified Ru–silica nanoparticles are immobilized on a 3-mercaptopropyl-trimethoxysilane-modified indium tin oxide electrode surface by Au–S interaction. The modified electrode exhibits excellent ECL signals.

    17. Photo- and Rubbing-Alignable Brush Polyimides Bearing Three Different Chromophores (pages 1359–1370)

      S. G. Hahm, T. J. Lee and M. Ree

      Article first published online: 12 APR 2007 | DOI: 10.1002/adfm.200600369

      Thumbnail image of graphical abstract

      New brush polyimides with three different chromophores are synthesized and aligned preferentially in films by both photo- and rubbing-alignment processes. The resulting films aligned liquid crystals along the oriented polymers. These are promising rubbing-free alignment-layer candidates for manufacturing liquid crystal display devices (see figure).

    18. Polyterthiophenes as Donors for Polymer Solar Cells (pages 1371–1376)

      M. Koppe, M. Scharber, C. Brabec, W. Duffy, M. Heeney and I. McCulloch

      Article first published online: 12 APR 2007 | DOI: 10.1002/adfm.200600859

      Thumbnail image of graphical abstract

      Polyterthiophenes (see figure) belong to a material class that has recently captured large interest for polymer electronic applications because of its excellent transport properties. Because of the slightly lower ionization potential, this material class appears more attractive for photovoltaic applications than polythiophenes.

    19. Poly(3-hexylthiophene) Fibers for Photovoltaic Applications (pages 1377–1384)

      S. Berson, R. De Bettignies, S. Bailly and S. Guillerez

      Article first published online: 18 APR 2007 | DOI: 10.1002/adfm.200600922

      Thumbnail image of graphical abstract

      Highly concentrated solutions of poly(3-hexylthiophene) nanofibers are obtained in p-xylene and used to fabricate ordered layers of nanofibers on various substrates without any thermal treatment. The figure shows an atomic force microscopy image of a network of these fibers. The fibers are used in the active layer of photovoltaic devices, and a maximum power conversion efficiency of 3.6 % is achieved for a solar cell based on a layer with a 75 wt % of fibers.

    20. Structure–Property–Function Relationships in Nanoscale Oxide Sensors: A Case Study Based on Zinc Oxide (pages 1385–1391)

      S. Polarz, A. Roy, M. Lehmann, M. Driess, F. E. Kruis, A. Hoffmann and P. Zimmer

      Article first published online: 12 APR 2007 | DOI: 10.1002/adfm.200700139

      Thumbnail image of graphical abstract

      Chemical sensing on metal-oxide sensors is a complex phenomenon involving redox catalysis and electrical conductivity; effects like surface area, grain size, and, in addition, the occurrence of defects give separate contributions to the current. The importance of nontexture effects are compared to texture effects using ZnO as a model system (see figure). Highly sensitive and stable sensors are described.

    21. Carbon-Decorated FePt Nanoparticles (pages 1392–1396)

      N. Caiulo, C. H. Yu, K. M. K. Yu, C. C. H. Lo, W. Oduro, B. Thiebaut, P. Bishop and S. C. Tsang

      Article first published online: 12 APR 2007 | DOI: 10.1002/adfm.200601200

      Thumbnail image of graphical abstract

      FePt nanoparticles with a carbon coating are obtained through hydrothermal treatment of iron and platinum precursors in a glucose solution. The hydrothermal treatment and subsequent calcination produces thermally stable fullerene-like carbon nanoparticles that encapsulate or decorate the FePt particles with sizes of ca. 5 nm (see figure). No severe macroscopic particle coalescence is observed from these coated particles.

    22. Nanometer-Sized Copper Sulfide Hollow Spheres with Strong Optical-Limiting Properties (pages 1397–1401)

      X.-L. Yu, C.-B. Cao, H.-S. Zhu, Q.-S. Li, C.-L. Liu and Q.-H. Gong

      Article first published online: 12 APR 2007 | DOI: 10.1002/adfm.200600245

      Thumbnail image of graphical abstract

      CuS semiconductor nanometer-sized hollow spheres (see figure) are successfully synthesized by using a soft-template method. A strong optical-limiting response is detected for the spheres in both visible and near infrared spectral ranges, which makes these promising materials for applications such as the protection of human eyes or as optical sensors for high-power laser irradiation.

    23. A Rapid and Efficient Method to Deposit Gold Particles onto Catalyst Supports and Its Application for CO Oxidation at Low Temperatures (pages 1402–1408)

      Z. Zhong, J. Lin, S.-P. Teh, J. Teo and F. M. Dautzenberg

      Article first published online: 3 APR 2007 | DOI: 10.1002/adfm.200601121

      Thumbnail image of graphical abstract

      The deposition of gold catalyst nanoparticles onto different oxidic supports is reported. The deposition process involves in situ reduction of the precursor solution with NaBH4, capping with an amino acid, and sonication to ensure adequate dispersion of the particles (see figure). The solution pH and the isoelectric point of the support material are found to have a strong influence on the properties of the catalysts.

    24. Biopolymer Networks for the Solid-State Production of Porous Magnetic Beads and Wires (pages 1409–1416)

      A. Bakandritsos, A. B. Bourlinos, V. Tzitzios, N. Boukos, E. Devlin, T. Steriotis, V. Kouvelos and D. Petridis

      Article first published online: 3 APR 2007 | DOI: 10.1002/adfm.200600681

      Thumbnail image of graphical abstract

      The morphosynthesis of capsules or wires by crosslinked biopolymer networks and pre-encapsulation of various reactants is described (see figure). Drying and pyrolysis afford solid, monolithic networks and, in turn, porous carbonaceous beads or fibers decorated with different inorganic nanoparticles, depending on the starting encapsulated reagents.

    25. Bacteriorhodopsin-Monolayer-Based Planar Metal–Insulator–Metal Junctions via Biomimetic Vesicle Fusion: Preparation, Characterization, and Bio-optoelectronic Characteristics (pages 1417–1428)

      Y. D. Jin, N. Friedman, M. Sheves and D. Cahen

      Article first published online: 18 APR 2007 | DOI: 10.1002/adfm.200600545

      Thumbnail image of graphical abstract

      Bacteriorhodopsin (bR)-containing metal–biomolecule–metal planar junctions are prepared via vesicle fusion tactics and soft Au top-electrode deposition. An electronic current can flow across these photoactive junctions (see figure). Optical characterization suggests that the photocurrents are associated with the photochemically induced M-like bR intermediate.

  5. Index

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

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