Advanced Functional Materials

Cover image for Vol. 17 Issue 2

January, 2007

Volume 17, Issue 2

Pages 175–332

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Full Papers
    6. Index
    1. Cover Picture: Solution-Processed Full-Color Polymer Organic Light-Emitting Diode Displays Fabricated by Direct Photolithography (Adv. Funct. Mater. 2/2007)

      M. C. Gather, A. Köhnen, A. Falcou, H. Becker and K. Meerholz

      Article first published online: 17 JAN 2007 | DOI: 10.1002/adfm.200790007

      Full-color polymer OLED displays are fabricated by using a novel photolithographic technique (see figure). Electroluminescent polymers with photoresist-like properties are made by attaching oxetane side groups to the polymers, allowing the structuring of thin films of these materials at high speed and high resolution.

  2. Inside Front Cover

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Full Papers
    6. Index
    1. Inside Front Cover: Fine Control of the Wettability Transition Temperature of Colloidal-Crystal Films: From Superhydrophilic to Superhydrophobic (Adv. Funct. Mater. 2/2007)

      J. Wang, Y. Wen, J. Hu, Y. Song and L. Jiang

      Article first published online: 17 JAN 2007 | DOI: 10.1002/adfm.200790008

      A facile strategy for finely controlling the wettability transition temperature of colloidal-crystal films is demonstrated. The temperature can be well tuned to 90, 80, 70, 60, 40, or even 20 °C, by adjusting the n-butyl acrylate/styrene ratio in the latex spheres (see figure). This approach may be extended to general materials to control the wettability behavior by chemical composition.

  3. Contents

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Full Papers
    6. Index
    1. Contents: Adv. Funct. Mater. 2/2007 (pages 175–181)

      Article first published online: 17 JAN 2007 | DOI: 10.1002/adfm.200790005

  4. Full Papers

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Full Papers
    6. Index
    1. Hierarchical Porosity in Self-Assembled Polymers: Post-Modification of Block Copolymer–Phenolic Resin Complexes by Pyrolysis Allows the Control of Micro- and Mesoporosity (pages 183–190)

      S. Valkama, A. Nykänen, H. Kosonen, R. Ramani, F. Tuomisto, P. Engelhardt, G. ten Brinke, O. Ikkala and J. Ruokolainen

      Article first published online: 19 DEC 2006 | DOI: 10.1002/adfm.200600604

      Thumbnail image of graphical abstract

      Self-assembled hierarchical porosity in polymers is achieved by using a facile method. The porosity (see figure) is tuned from mesoporous to hierarchically micro-mesoporous simply by controlling the pyrolysis conditions of cured block-copolymer–phenolic resin complexes. The relative amount of micro- and mesopores can be tuned in situ by post modification.

    2. Solution-Processed Full-Color Polymer Organic Light-Emitting Diode Displays Fabricated by Direct Photolithography (pages 191–200)

      M. C. Gather, A. Köhnen, A. Falcou, H. Becker and K. Meerholz

      Article first published online: 17 JAN 2007 | DOI: 10.1002/adfm.200600651

      Thumbnail image of graphical abstract

      Full-color polymer OLED displays are fabricated by using a novel photolithographic technique (see figure). Electroluminescent polymers with photoresist-like properties are made by attaching oxetane side groups to the polymers, allowing the structuring of thin films of these materials at high speed and high resolution.

    3. UV-Light-Driven Immobilization of Surface-Functionalized Oxide Nanocrystals onto Silicon (pages 201–211)

      E. Fanizza, P. D. Cozzoli, M. L. Curri, M. Striccoli, E. Sardella and A. Agostiano

      Article first published online: 17 JAN 2007 | DOI: 10.1002/adfm.200600288

      Thumbnail image of graphical abstract

      Oxide nanocrystals capped with unsaturated carboxylic acids can be efficiently attached to hydrogenated Si through a UV-activated reaction. TiO2-modified Si substrates can be further functionalized with Au nanoparticles via an oxide-catalyzed visible-light-driven reduction of AuCl4 ions (see figure).

    4. A Quantum-Splitting Phosphor Exploiting the Energy Transfer from Anion Excitons to Tb3+ in CaSO4:Tb,Na (pages 212–218)

      A. R. Lakshmanan, S.-B. Kim, H. M. Jang, B. G. Kum, B. K. Kang, S. Heo and D. Seo

      Article first published online: 19 DEC 2006 | DOI: 10.1002/adfm.200600010

      Thumbnail image of graphical abstract

      The vacuum ultraviolet (VUV) excitation (left) and emission spectra (right) of a CaSO4:Tb phosphor (red lines) are compared with those of the standard commercial green plasma display panel (PDP) phosphor YBO3:Tb (black lines). The intense green emission line at 545 nm corresponds to 5D4[RIGHTWARDS ARROW]7F5 electronic transition. The quantum efficiency of CaSO4:Tb under VUV excitation at 147 nm is estimated to be higher than 100 %.

    5. Fine Control of the Wettability Transition Temperature of Colloidal-Crystal Films: From Superhydrophilic to Superhydrophobic (pages 219–225)

      J. Wang, Y. Wen, J. Hu, Y. Song and L. Jiang

      Article first published online: 19 DEC 2006 | DOI: 10.1002/adfm.200600101

      Thumbnail image of graphical abstract

      A facile strategy for finely controlling the wettability transition temperature of colloidal-crystal films is demonstrated. The temperature can be well tuned to 90, 80, 70, 60, 40, or even 20 °C, by adjusting the n-butyl acrylate/styrene ratio in the latex spheres (see figure). This approach may be extended to general materials to control the wettability behavior by chemical composition.

    6. An Efficient Bulk-Heterojunction Photovoltaic Cell Based on Energy Transfer in Graded-Bandgap Polymers (pages 226–232)

      D. Gupta, D. Kabra, N. Kolishetti, S. Ramakrishnan and K. S. Narayan

      Article first published online: 5 DEC 2006 | DOI: 10.1002/adfm.200600183

      Thumbnail image of graphical abstract

      Energy transfer (ET) from low- conjugated (LC) poly[2-methoxy-5- (2-ethylhexyloxy)-1,4-phenylene vinylene] (MEHPPV) to high-conjugated (HC) MEHPPV, coupled with significant charge transfer (CT) from HC-MEHPPV to an acceptor species (CNPPV), offers a viable route towards efficient photodiodes. The figure shows the photophysical process initiated by blue light in the ternary donor–acceptor polymer-blend system.

    7. Adenoviral Gene Delivery from Multilayered Polyelectrolyte Architectures (pages 233–245)

      M. Dimitrova, Y. Arntz, P. Lavalle, F. Meyer, M. Wolf, C. Schuster, Y. Haïkel, J.-C. Voegel and J. Ogier

      Article first published online: 19 DEC 2006 | DOI: 10.1002/adfm.200600155

      Thumbnail image of graphical abstract

      A bioactive adenoviral vector is embedded into multilayered polyelectrolyte films. Ad efficiently adsorbs on poly(L-lysine)–poly(L-glutamic acid), poly(L-lysine)–hyaluronan, poly(allylamin hydrochloride)–poly(sodium-4-styrenesulfonate) (see the AFM image), and chitosan–hyaluronan films, and preserves its transduction capacity for a large number of cell types.

    8. Design of Poly(vinyldiaminotriazine)-Based Nonviral Vectors via Specific Hydrogen Bonding with Nucleic Acid Base Pairs (pages 246–252)

      Z. Q. Cao, W. G. Liu, D. C. Liang, G. Guo and J. Y. Zhang

      Article first published online: 19 DEC 2006 | DOI: 10.1002/adfm.200600271

      Thumbnail image of graphical abstract

      Poly(vinyldiaminotriazine)-based nonviral vectors have been designed, capable of efficiently complexing plasmid DNA to condense DNA into spheres and toroids by specific hydrogen bonds with nucleic acid base pairs, thereby contributing to an effective transfection of COS-1 cells (see figure).

    9. Substituent Effects on Crosslike Packing of 2′,7′-Diaryl- spiro(cyclopropane-1,9′-fluorene) Derivatives: Synthesis and Crystallographic, Optical, and Thermal Properties (pages 253–263)

      Z. Wang, H. Shao, J. Ye, L. Zhang and P. Lu

      Article first published online: 5 JAN 2007 | DOI: 10.1002/adfm.200600314

      Thumbnail image of graphical abstract

      Photophysical analysis of a series of 2′,7′-diarylspiro(cyclopropane-1,9′- fluorene) derivatives shows clear evidence that crosslike molecular packing blocks efficient intermolecular π–π interactions between adjacent fluorenes, even though small dialkyl groups are introduced at the C-9 position of the fluorenes. This suggests that the “green” emission tail is caused by keto byproducts arising from the oxidation of fluorene (see figure).

    10. Band-Offset Engineering for Enhanced Open-Circuit Voltage in Polymer–Oxide Hybrid Solar Cells (pages 264–269)

      D. C. Olson, S. E. Shaheen, M. S. White, W. J. Mitchell, M. F. A. M. van Hest, R. T. Collins and D. S. Ginley

      Article first published online: 13 DEC 2006 | DOI: 10.1002/adfm.200600215

      Thumbnail image of graphical abstract

      Substitution of magnesium into a zinc oxide acceptor (Zn1–xMgxO) results in a simple method to systematically tune the band offset in a p-conjugated polymer–metal oxide hybrid donor– acceptor system in order to maximize the VOC (see figure). The VOC is seen to increase from 500 mV at x = 0 up to values in excess of 900 mV at x = 0.35. This work provides a tool to understand the role of the donor–acceptor band offset in hybrid photovoltaics.

    11. Tailoring the Optical Properties of Epitaxially Grown Biaxial ZnO/Ge, and Coaxial ZnO/Ge/ZnO and Ge/ZnO/Ge Heterostructures (pages 270–276)

      L.-W. Yin, M.-S. Li, Y. Bando, D. Golberg, X. L. Yuan and T. Sekiguchi

      Article first published online: 5 JAN 2007 | DOI: 10.1002/adfm.200600065

      Thumbnail image of graphical abstract

      Unique heterostructures of epitaxially grown biaxial and coaxial Ge/ZnO heterojunction nanowires with nanoscale contact between the ZnO semiconductor and Ge sublayer are fabricated (see figure). Sharp interfaces and good epitaxial relationships between the ZnO and Ge sublayers in the heterostructures are formed, leading to unique luminescence properties; thus, their potential asbasic components in miniaturized semiconductor devices is envisaged.

    12. Controlled Pattern Formation of Poly[2-methoxy-5-(2′-ethylhexyloxyl)–1,4-phenylenevinylene] (MEH–PPV) by Ink-Jet Printing (pages 277–284)

      E. Tekin, E. Holder, D. Kozodaev and U. S. Schubert

      Article first published online: 13 DEC 2006 | DOI: 10.1002/adfm.200600049

      Thumbnail image of graphical abstract

      Well-defined and flat thin films of a poly(phenylene vinylene) derivative (MEH–PPV) are obtained by ink-jet printing (see figure) solutions. This technique has potential device applications, for example, in polymer field- effect transistor fabrication. The effects of interchain interactions of MEH–PPV in different organic solvents on the processability, film formation, and electrical characteristics are investigated.

    13. NCN-Coordinated Platinum(II) Complexes as Phosphorescent Emitters in High-Performance Organic Light-Emitting Devices (pages 285–289)

      M. Cocchi, D. Virgili, V. Fattori, D. L. Rochester and J. A. G. Williams

      Article first published online: 5 JAN 2007 | DOI: 10.1002/adfm.200600167

      Thumbnail image of graphical abstract

      External electroluminescence quantum efficiencies of 4–16 % and luminous efficiencies of 15–40 cd A–1 maintained over a four-decade current intensity span have been achieved with terdentate PtII complexes. Color tuning was achieved by ligand substitution, resulting in emission in the yellow, deep green, and blue range (see figure).

    14. Cationic Conjugated Polyelectrolytes with Molecular Spacers for Efficient Fluorescence Energy Transfer to Dye-Labeled DNA (pages 290–295)

      H. Y. Woo, D. Vak, D. Korystov, A. Mikhailovsky, G. C. Bazan and D.-Y. Kim

      Article first published online: 12 DEC 2006 | DOI: 10.1002/adfm.200600093

      Thumbnail image of graphical abstract

      Two cationic conjugated polyelectrolytes (CCPs, see figure) with similar optical/electronic properties but different molecular structures act as fluorescence resonance energy transfer (FRET) donors to fluorescein (FL)-labeled single-stranded DNA. Comparison of their efficiencies of energy transfer indicates that backbone modification with “molecular bumpers” fine-tunes the competition between FRET and photoinduced charge-transfer (PCT) mechanisms.

    15. From Layered Basic Zinc Acetate Nanobelts to Hierarchical Zinc Oxide Nanostructures and Porous Zinc Oxide Nanobelts (pages 296–306)

      R.-Q. Song, A.-W. Xu, B. Deng, Q. Li and G.-Y. Chen

      Article first published online: 5 JAN 2007 | DOI: 10.1002/adfm.200600024

      Thumbnail image of graphical abstract

      Layered basic zinc acetate nanobelts (see figure) are prepared by using a simple aqueous synthetic method under mild conditions. Novel hierarchical ZnO nanostructures and porous ZnO nanobelts and nanoparticle chains are obtained from these layered basic zinc acetate nanobelts by refluxing and calcination, respectively.

    16. Heterostructured Visible-Light-Active Photocatalyst of Chromia-Nanoparticle-Layered Titanate (pages 307–314)

      T. W. Kim, S. G. Hur, S.-J. Hwang, H. Park, W. Choi and J.-H. Choy

      Article first published online: 5 JAN 2007 | DOI: 10.1002/adfm.200600022

      Thumbnail image of graphical abstract

      Heterostructured visible-light photocatalysts are obtained through the hybridization of titanate nanosheets and chromia nanoparticles (see figure). An exfoliation–restacking technique leads to the formation of highly porous heterostructures with excellent thermal stability. The nanohybrid photocatalysts make possible the effective degradation of organic pollutants under visible-light irradiation.

    17. Efficient Organic Light-Emitting Diodes based on Sublimable Charged Iridium Phosphorescent Emitters (pages 315–323)

      W.-Y. Wong, G.-J. Zhou, X.-M. Yu, H.-S. Kwok and Z. Lin

      Article first published online: 5 JAN 2007 | DOI: 10.1002/adfm.200600359

      Thumbnail image of graphical abstract

      Charged bis-cyclometalated iridium diimine complexes of (9,9-diethyl-7-pyridinylfluoren-2-yl)diphenylamine (see figure) are shown to be morphologically and thermally stable solids. They can be readily sublimed and used as electrophosphors in the fabrication of efficient organic light-emitting diodes using the vacuum deposition technique.

    18. Optimized Preparation of Elastically Soft, Highly Piezoelectric, Cellular Ferroelectrets from Nonvoided Poly(ethylene Terephthalate) Films (pages 324–329)

      W. Wirges, M. Wegener, O. Voronina, L. Zirkel and R. Gerhard-Multhaupt

      Article first published online: 5 JAN 2007 | DOI: 10.1002/adfm.200600162

      Thumbnail image of graphical abstract

      From nonvoided poly(ethylene terephthalate) (“polyester”) films, cellular ferroelectrets with application-relevant piezoelectric coefficients up to almost 500 pC N–1 are produced by means of an optimized preparation sequence: foaming with carbon dioxide, biaxial mechanical stretching, controlled void inflation (see figure), and bipolar Pelectric charging.

  5. Index

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Full Papers
    6. Index
    1. Author Index and Subject Index Adv. Funct. Mater. 2/2007 (pages 331–332)

      Article first published online: 17 JAN 2007 | DOI: 10.1002/adfm.200790006

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