Advanced Functional Materials

Cover image for Vol. 19 Issue 3

February 10, 2009

Volume 19, Issue 3

Pages 339–498

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Feature Article
    6. Frontispiece
    7. Full Papers
    8. Index
    1. Directed Helical Growth: A Spring-Like Behavior of Chiral Block Copolymer with Helical Nanostructure Driven by Crystallization (Adv. Funct. Mater. 3/2009)

      Yeo-Wan Chiang, Rong-Ming Ho, Edwin L. Thomas, Christian Burger and Benjamin S. Hsiao

      Version of Record online: 2 FEB 2009 | DOI: 10.1002/adfm.200990004

      Thumbnail image of graphical abstract

      Crystalline helices (PLLA crystallization directed by helical confined microdomains) and crystalline cylinders (phase transformation of helical nano structures dictated by crystallization) are obtained by controlling the crystallization temperature of PLLA with respect to the glass transition temperature of PS in PS-PLLA block copolymers; this process is described by J.-W. Chiang et al. on page 448. A spring-like behavior of the PLLA helical nanostructures embedded in the PS matrix can be driven by crystallization, so as to dictate the transformation of the helices, resulting in crystalline cylinders that might represent a possible avenue for the design of switchable large-strain actuators.

  2. Inside Front Cover

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Feature Article
    6. Frontispiece
    7. Full Papers
    8. Index
    1. Liquid-Crystalline Nanostructures: π-Conjugated Oligothiophene-Based Polycatenar Liquid Crystals: Self-Organization and Photoconductive, Luminescent, and Redox Properties (Adv. Funct. Mater. 3/2009)

      Takuma Yasuda, Hirotaka Ooi, Jun Morita, Yusuke Akama, Kiyoshi Minoura, Masahiro Funahashi, Takeshi Shimomura and Takashi Kato

      Version of Record online: 2 FEB 2009 | DOI: 10.1002/adfm.200990005

      Thumbnail image of graphical abstract

      Polycatenar π-conjugated oligothiophenes tethering multiple flexible chains can be used as electro-, photo-, and redox-active materials, as reported by Takashi Kato, Takuma Yasuda, and co-workers on page 411. Various functional liquid-crystalline assemblies including smectic, columnar, and micellar cubic nanostructures can be constructed by polycatenar oligothiophenes. This simple and versatile design strategy would be useful for further development of new functional π-conjugated materials.

  3. Contents

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Feature Article
    6. Frontispiece
    7. Full Papers
    8. Index
  4. Feature Article

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Feature Article
    6. Frontispiece
    7. Full Papers
    8. Index
    1. Development and Testing of Energetic Materials: The Concept of High Densities Based on the Trinitroethyl Functionality (pages 347–365)

      Michael Göbel and Thomas M. Klapötke

      Version of Record online: 12 JAN 2009 | DOI: 10.1002/adfm.200801389

      Thumbnail image of graphical abstract

      Higher density, a prerequisite for the design of next generation energetic materials is shown to be dependent on noncovalent bonding interactions. The graphic displays BTAT, a structural isomer of CL-20 which is one of the most powerful organic explosives at present. A high-speed video frame (0.28 ms) of the thermal decomposition (steel sleeve test) is shown in the background.

  5. Frontispiece

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Feature Article
    6. Frontispiece
    7. Full Papers
    8. Index
    1. Flame-Synthesized Copper Dimers: Flame-Synthesized Ceria-Supported Copper Dimers for Preferential Oxidation of CO (Adv. Funct. Mater. 3/2009)

      Richard Kydd, Wey Yang Teoh, Kenneth Wong, Yong Wang, Jason Scott, Qing-Hua Zeng, Ai-Bing Yu, Jin Zou and Rose Amal

      Version of Record online: 2 FEB 2009 | DOI: 10.1002/adfm.200990007

      Thumbnail image of graphical abstract

      On page 369, R. Kydd et al. describe the creation of highly dispersed copper dimers (violet areas) on Ceria nanoparticles (green areas) via rapid flame-spray pyrolysis. These as-prepared copper dimers, in synergism with the oxygen vacancies in ceria, exhibit favourable electronic and catalytic interactions with incident CO molecules. Consequently, CO can be preferentially oxidised in H2 streams at low temperatures.

  6. Full Papers

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Feature Article
    6. Frontispiece
    7. Full Papers
    8. Index
    1. Flame-Synthesized Ceria-Supported Copper Dimers for Preferential Oxidation of CO (pages 369–377)

      Richard Kydd, Wey Yang Teoh, Kenneth Wong, Yong Wang, Jason Scott, Qing-Hua Zeng, Ai-Bing Yu, Jin Zou and Rose Amal

      Version of Record online: 2 DEC 2008 | DOI: 10.1002/adfm.200801211

      Thumbnail image of graphical abstract

      Flame spray pyrolysis (FSP) produces highly dispersed Cu–CeO2 catalysts. Transformation of the Cu species from monomer to dimer takes place as Cu content increases. As-prepared catalysts display high and stable activity for the preferential oxidation of CO (PROX). This work demonstrates how structural and electronic changes lead to heightened levels of reducibility and catalytic activity and shows that FSP is an effective and simple strategy for producing highly active PROX catalysts.

    2. Enhancement of Carrier Mobilities of Organic Semiconductors on Sol–Gel Dielectrics: Investigations of Molecular Organization and Interfacial Chemistry Effects (pages 378–385)

      Tommy Cahyadi, Johnson Kasim, Huei Shuan Tan, Shripad R. Kulkarni, Beng S. Ong, Yiliang Wu, Zhi-Kuan Chen, Chee Mang Ng, Ze-Xiang Shen and Subodh G. Mhaisalkar

      Version of Record online: 12 JAN 2009 | DOI: 10.1002/adfm.200800929

      Thumbnail image of graphical abstract

      Dielectric-semiconductor interfacial interactions critically influence morphology and molecular ordering of organic semiconductor molecules, and hence have a profound influence on vital device characteristics of organic field-effect transistors. Different classes of semiconductors deposited on sol–gel silica gate-dielectric show significant enhancement in device mobilities, attributable to improved crystal structure, grain size as well as enhanced molecular interactions and ordering.

    3. Ambipolar Organic Field-Effect Transistors from Cross-Conjugated Aromatic Quaterthiophenes; Comparisons with Quinoidal Parent Materials (pages 386–394)

      Rocío Ponce Ortiz, Antonio Facchetti, Tobin J. Marks, Juan Casado, Marek Z. Zgierski, Masatoshi Kozaki, Víctor Hernández and Juan T. López Navarrete

      Version of Record online: 12 JAN 2009 | DOI: 10.1002/adfm.200801066

      Thumbnail image of graphical abstract

      Playing with molecular conjugation, prime figures of ambipolar (hole and electron conduction) charge transport are found in molecules with cross-conjugated thiophene skeletons. The interest lies in the combination of electron acceptors inserted laterally to the main, hole transmitter, conjugational path. Molecular spectroscopy and electrochemistry provide insight into macroscopic electrical behavior.

    4. Isolation of Solid Solution Phases in Size-Controlled LixFePO4 at Room Temperature (pages 395–403)

      Genki Kobayashi, Shin-ichi Nishimura, Min-Sik Park, Ryoji Kanno, Masatomo Yashima, Takashi Ida and Atsuo Yamada

      Version of Record online: 23 DEC 2008 | DOI: 10.1002/adfm.200801522

      Thumbnail image of graphical abstract

      Solid solution phases in LixFePO4 close to x = 0 and x = 1 are successfully isolated at room temperature. Investigation of the isolation processes and isolated phases for various mean particle sizes leads to the verification of the size-dependent miscibility gap model. Coupled inspections of the equilibrium open-circuit potential and the lattice dimensions show that the bulk miscibility dominates the electrochemical behavior of LixFePO4.

    5. Tuning and Transcription of the Supramolecular Organization of a Fluorescent Silsesquioxane Precursor into Silica-Based Materials through Direct Photochemical Hydrolysis–Polycondensation and Micropatterning (pages 404–410)

      Xavier Sallenave, Olivier J. Dautel, Guillaume Wantz, Pierre Valvin, Jean-Pierre Lère-Porte and Joel J. E. Moreau

      Version of Record online: 18 DEC 2008 | DOI: 10.1002/adfm.200801387

      Thumbnail image of graphical abstract

      A completely controlled preparation of patterned thin hybrid films is demonstrated: from the synthesis of a silsesquioxane precursor with tuned optical and organizational properties, its self-assembling into J-aggregates, the transcription of the supramolecular structure into the sol– gel matrix by a new photochemical hydrolysis–polycondensation step, and finally, micropatterning (see figure), which involves chemically amplified photolithography.

    6. π-Conjugated Oligothiophene-Based Polycatenar Liquid Crystals: Self-Organization and Photoconductive, Luminescent, and Redox Properties (pages 411–419)

      Takuma Yasuda, Hirotaka Ooi, Jun Morita, Yusuke Akama, Kiyoshi Minoura, Masahiro Funahashi, Takeshi Shimomura and Takashi Kato

      Version of Record online: 12 DEC 2008 | DOI: 10.1002/adfm.200801268

      Thumbnail image of graphical abstract

      π-Conjugated oligothiophenes tethering multiple flexible chains can self-organize into liquid-crystalline smectic, columnar, and micellar cubic phases. These molecular assemblies can function as charge- transporting, luminescent, and redox-active materials, and are potentially useful for a wide variety of electronic applications.

    7. Highly Efficient Red Phosphorescent OLEDs based on Non-Conjugated Silicon-Cored Spirobifluorene Derivative Doped with Ir-Complexes (pages 420–427)

      Yi-Yeol Lyu, Jeonghun Kwak, Woo Sung Jeon, Younghun Byun, Hyo Sug Lee, Doseok Kim, Changhee Lee and Kookheon Char

      Version of Record online: 12 JAN 2009 | DOI: 10.1002/adfm.200801319

      Thumbnail image of graphical abstract

      A new host material for red phosphorescent emitters containing silicon-cored spirobifluorene derivative (SBP-TS-PSB) is synthesized. This material has excellent thermal and morphological stabilities and exhibits high electroluminescence efficiency as a host for red phosphorescent OLEDs. When doped with a typical red phosphorescent dopant (piq)2Ir(acac) a maximum external quantum efficiency of ηext = 14.6% is achieved. This high performance can be mainly explained by improved charge balance attributable to the bipolar characteristics of the spirobifluorene group.

    8. Enhanced Photorefractivity of Poly(N-vinylcarbazole)-Based Composites through Electric-Field Treatments and Ionic Liquid Doping (pages 428–437)

      José A. Quintana, José M. Villalvilla, Pedro G. Boj, Luis Martín-Gomis, Javier Ortiz, Fernando Fernández-Lázaro, Ángela Sastre-Santos and María A. Díaz García

      Version of Record online: 2 JAN 2009 | DOI: 10.1002/adfm.200800790

      Thumbnail image of graphical abstract

      The addition of an organic ionic liquid, for example benzalkonium chloride (BAC), to an unsensitized photorefractive (PR) polymer composite leads to a significant increase of the two-beam-coupling net gain coefficient and a decrease of the PR speed. This effect is observed only when samples are subjected to an electric-field (i.e., 20 V μm–1 for 20 min) prior to PR characterization.

    9. Combined Effect of Nitrogen- and Oxygen-Containing Functional Groups of Microporous Activated Carbon on its Electrochemical Performance in Supercapacitors (pages 438–447)

      Denisa Hulicova-Jurcakova, Mykola Seredych, Gao Qing Lu and Teresa J. Bandosz

      Version of Record online: 18 DEC 2008 | DOI: 10.1002/adfm.200801236

      Thumbnail image of graphical abstract

      Analysis of the combined effect of porosity and nitrogen and oxygen content of modified activated carbons on their supercapacitive performance reveals that pores with a mean diameter of 5.2 Å are the most effective in a double-layer formation while pyridinic (I-N5) and pyrrolic (I-N6) nitrogen and quinone (I-OI) oxygen indices located in pores bigger than 10 Å are the electrochemically active pseudocapacitive functional groups.

    10. A Spring-Like Behavior of Chiral Block Copolymer with Helical Nanostructure Driven by Crystallization (pages 448–459)

      Yeo-Wan Chiang, Rong-Ming Ho, Edwin L. Thomas, Christian Burger and Benjamin S. Hsiao

      Version of Record online: 30 DEC 2008 | DOI: 10.1002/adfm.200801372

      Thumbnail image of graphical abstract

      Crystalline helices and cylinders are obtained by controlling the crystallization temperature of poly(L-lactide) (PLLA) with respect to the glass transition temperature of poly(styrene) (PS) in PS-PLLA block copolymers. A spring-like behavior of the PLLA helical nanostructures embedding in the PS matrix can be driven by crystallization so as to dictate the transformation of helices, resulting in crystalline cylinders that might be applicable to the design of switchable large-strain actuators.

    11. Formation and Properties of Responsive Siloxane-Based Polymeric Surfaces with Tunable Surface Reconstruction Kinetics (pages 460–469)

      Julie Ann Crowe-Willoughby and Jan Genzer

      Version of Record online: 30 DEC 2008 | DOI: 10.1002/adfm.200800622

      Thumbnail image of graphical abstract

      The formation of responsive surfaces with ultrafast and tailorable surface-reconstruction kinetics and switching hysteresis by thiol-ene radical addition of mercaptoalkanols with variable lengths to poly(vinylmethylsiloxane) (PVMS) networks is reported. Exposing these surfaces to water results in rapid segregation of the hydrophilic alkanols from the bulk to the surface; the situation reverses when water is removed from the PVMS substrates.

    12. Metal Ion Implantation for the Fabrication of Stretchable Electrodes on Elastomers (pages 470–478)

      Samuel Rosset, Muhamed Niklaus, Philippe Dubois and Herbert R. Shea

      Version of Record online: 18 DEC 2008 | DOI: 10.1002/adfm.200801218

      Thumbnail image of graphical abstract

      Metal ion implantation on elastomers is used to create stretchable electrodes. The implantation leads to the formation of nanometer-size clusters at the elastomer's surface, which create deformable conductive paths. Uniaxial strains of 175% are observed before loss of electrical conductivity.

    13. A General Strategy to Disperse and Functionalize Carbon Nanotubes Using Conjugated Block Copolymers (pages 479–483)

      Jianhua Zou, Saiful I. Khondaker, Qun Huo and Lei Zhai

      Version of Record online: 18 DEC 2008 | DOI: 10.1002/adfm.200800542

      Thumbnail image of graphical abstract

      A general strategy to disperse and functionalize pristine carbon nanotubes is developed using conjugated block copolymers. The conjugated polymer block can form strong π-π interactions with carbon nanotube walls, while the non-conjugated polymer block provides the de-bundled CNTs with good solubility and stability in a wide range of organic solvents and host polymer matrices, as well as various functionalities.

    14. Field Emission and Cathodoluminescence of ZnS Hexagonal Pyramids of Zinc Blende Structured Single Crystals (pages 484–490)

      Zhi-Gang Chen, Jin Zou, Dai-Wei Wang, Li-Chang Yin, Gang Liu, Qingfeng Liu, Cheng-Hua Sun, Xiangdong Yao, Feng Li, Xiao-Li Yuan, Takashi Sekiguchi, Gao Qing Lu and Hui-Ming Cheng

      Version of Record online: 12 JAN 2009 | DOI: 10.1002/adfm.200801178

      Thumbnail image of graphical abstract

      ZnS hexagonal pyramids, consisting of zinc blende structured single crystals with a nanotip, are fabricated by a facile thermal evaporation method. Stable and strong UV emission at 337 nm and superior field emission with a low turn-on field, high field-enhancement factor, large current density, and small fluctuation are observed. The figure shows the growth mechanism of the ZnS pyramids.

    15. Highly Efficient Hole Injection Using Polymeric Anode Materials for Small-Molecule Organic Light-Emitting Diodes (pages 491–496)

      Kaushik Roy Choudhury, Jaewon Lee, Neetu Chopra, Alok Gupta, Xuezhong Jiang, Fabrice Amy and Franky So

      Version of Record online: 8 JAN 2009 | DOI: 10.1002/adfm.200801368

      Thumbnail image of graphical abstract

      Efficient hole injection in organic light-emitting diodes (OLEDs) is difficult to achieve due to the low work function of indium tin oxide. Here, very efficient hole injection is demonstrated using a novel polythienothiophene (PTT) conducting polymer (see image). The work function of the PTT-based polymer can be tuned from 5.2 eV to 5.7 eV, resulting in a substantial enhancement in hole injection and reduction in operating voltage.

  7. Index

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Feature Article
    6. Frontispiece
    7. Full Papers
    8. Index

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