Advanced Materials

Cover image for Advanced Materials

November 1995

Volume 7, Issue 11

Pages fmi–fmi, 893–951

  1. Masthead

    1. Top of page
    2. Masthead
    3. Essay
    4. Communications
    5. Research News
    6. Talking Points
    1. Masthead (page fmi)

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071101

  2. Essay

    1. Top of page
    2. Masthead
    3. Essay
    4. Communications
    5. Research News
    6. Talking Points
    1. Diversity as a program: Research center jülich (pages 893–895)

      Dr. Herbert Munder and Dr. Jens Simon

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071102

      The research center in Jülich is the largest of the 16 national research centers in the Federal Republic of Germany. This year, the center is 40 years old and has an anual budget of DM 485 million. In the early years the center concentrated on nuclear power-related technologies but now research carried out at the center is very interdisciplinary and very diverse. The development of the center is described, the current research priorities presented and a view of an interdisciplinary materials research future is discussed.

  3. Communications

    1. Top of page
    2. Masthead
    3. Essay
    4. Communications
    5. Research News
    6. Talking Points
    1. Template synthesis of graphitic nanotubules (pages 896–897)

      Ranjani V. Parthasarathy, K. L. N. Phani and Prof. Charles R. Martin

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071103

      Ensembles of graphite-based nanotubes (see Fig.) have been produced by extending a template approach successfully used for metals and semiconductors to carbons. The outer andinner diameters of the tubules can be controlled by varying the time allowed for the polymerization of acrylonitrile within the pores of a nanotubes formed in the pores are subsequently graphitized at high temperatures to form the graphitized nanotubes

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    2. Charge transport polymers for light emitting diodes (pages 898–900)

      Dr. Xiao-Chang Li, Tuck Mun Yong, Dr. Franco Cacialli, Dr. Johannes Grüner, Prof. Richard H. Friend, Dr. Andrew B. Holmes, Mark Giles and Dr. Stephen C. Moratti

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071104

      Electron transport polymers containing aromatic oxadiazole side chain chromophores have been designed and synthesized. They have been found useful for improving the quantum efficiency, lowering the turn-on voltage, and enabling the use of the more stable aluminum cathode in the fabrication of polymer LEDs. As the oxadiazole units are chemically bound to the polymer chain, rather than being simply dispersed in a polymer matrix, the materials are expected to exhibit long-term morphological stability. The synthesis and several different applications are presented.

    3. Ultraviolet electroluminescence from an organic light emitting diode (pages 900–903)

      Magnus Berggren, Magnus Granströim, Prof. Olle Inganas and Dr. Mats Andersson

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071105

      The extension of the emission region or organic LEDs into the ultraviolet region is reported. Emission at 394 nm is achieved by modifying the geometry of a device based on poly(octylphenyl)bithiophene (PTOPT) and poly(octylphenyl)oxadiazole (PBD) which had previously been shown to emit white light. Through changing the geometry the red and green emission peaks have been suppressed and the UV band (from the PBD) enhanced

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    4. Red-orange electroluminescence with new soluble and air-stable poly(naphthalene-vinylene)s (pages 903–906)

      Stefan Tasch, Dr. Wilhelm Groaupner, Prof. Günther Leising, Dr. Lin Pc, Dr. Martin W. Wagner and Prof. Robert H. Grubbs

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071106

      The optical and electronic properties of new soluble derivatives of poly(naphthalene-vinylene) (PNV) with different length alkyl side groups are reported. Quantum efficiencies of up to 10% and power efficiencies of up to 0.02% have been attained from polymer-LEDs based on these materials, and the polymers themselves are found to have a well-defined chemical structure and exhibit little main-chain stiffness.

    5. Push-pull substituted polythiophenes: towards charge confinement in molecular quantum wells (pages 907–910)

      Prof. Frederic Demanze, Dr. Abderrahim Yassar and Dr. Francis Garnier

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071107

      Poly(bithiophene) dervatives unsymmetrically substituted with strong electron-donating groups and strong electron-withdrawing groups (e.g. see Fig.) have been synthesized. The substituents induce electronic push–pull effects along the conjugated chain which could be exploited in the design of organic-based multiple quantum well structures

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    6. A polysiloxane-based photorefractive polymer with high optical gain and diffraction efficiency (pages 911–914)

      O. Zobel, M. Eckl, D. R. P. Strohriegl, Martin Eckl, Peter Strohriegl and Prof. Dietrich Haarer

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071108

      Photorefractive polymers have gret potential in applications such as all-optical switching and optical communication. Here, new charge-transporting polymers are presented based on a polysiloxane backbone with pendant carbazole groups, which provide both transport and room-temperature poling properties without the need for additional plasticizing components. A quantitative evaluation of the phase behavior of holographic gratings based on the new materials is also presented.

    7. Design of a solvatochromic polymer-based fiber optics chemical sensor for polar solvent detection (pages 914–917)

      Dr. Denis Fichou, Dr. Christine Hubert and Dr. Francis Garnier

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071109

      An optical sensor for organic solvents with a detection limit of 10−2 v/v-% for methanol in mixed hydrocarbons is presented. The system, a fiber optic chemical sensor based on Reichardt's dye covalently bound to an insoluble Merrifield peptide resin (see Fig.), is shown to have a response time of ca. 1 minute

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    8. Third-order nonlinear optical properties of thin films of organogermane homopolymers and organogermane-organosilane copolymers (pages 917–919)

      Takuo Kodaira, Prof. Akira Watanabe, Prof. Osamu Ito, Prof. Minoru Matsuda, Satoshi Tokura, Prof. Mitsuo Kira, Shuh-Saku Nagano and Prof. Kunio Mochida

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071110

      σ-conjugated polysilanes and polygermanes are known to possess interesting linear optical properties as well as unique physical and chemical properties. Unlike π-conjugated carbon-based polymers these materials are transparent in the visible and strongly absorbing in the near ultraviolet region. Here, the nonlinear optical properties, in particular those for third harmonic generation, for several polygermane homopolymers and a polygermane-polysilane copolymer are presented.

    9. The influence of surface structure on the discotic liquid crystalline alignment. an infrared spectroscopy study (pages 919–922)

      Dr. Tunic S. Perora and Prof. Jagdish K. Vij

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071111

      The type of alignment achieved with discotic liquid crystals is important for a number of applications. It is found to depend decisively on the structure of the substrate. Infrared dichroism experiments are used to study the alignment of truxene and triphenylene cores (see Fig.) on amorphous silicon and polycrystalline ZnSe substrates, revealing considerable differences and hinting at the opportunity to tune the alignment of the materials

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    10. Polarized photoluminescence of liquid crystalline polymers with isolated arylenevinylene segments in the main chain (pages 923–925)

      Prof. J. H. Wendroff, Georg Lüssem, Reiner Festag, Dr. Andreas Greiner, Claudia Schmidt, Christoph Unterlechner and Prof. Walter Heitz

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071112

      Anisotropic charge transport, or polarized photo- and electroluminescence are possible applications for materials combining the optical properties of arylenevinylene polymers with the characteristic orientational order of the liquid-crystalline state. Thermally stale, soluble materials with a broad mesophase, which can be oriented macroscopically using conventional processing techniques and when exhibit highly anisotropic luminescence behavior of use in polarized LEDs are presented.

    11. Effective synthesis of HgBa2Ca2CU308+y, the highest Tc superconductor (pages 925–927)

      Graeme B. Peacock, Ian Ganzeson, Wuzhong Zhou, Prof. Peter P. Edwards, Marcin Slaski, Wuzhong Zhou and John R. Cooper

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071113

      The preparation of the superconductor Hg-1223 (see this month's title picture) with 60-70% phase purity by a simplified route is reported. The material is produced in a single step from air-stable mono-oxides and exhibits a sharp superconducting transition, possibly due to the lack of observable defects (see Fig.)

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    12. Polaron migration in doped polysilanes: am i calculations on the radical cation Si17(CH3)36+ (pages 927–929)

      Dr. Timothy Clark, Mwzfioed Gröppel and Dr. Wolfgang Roth

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071114

      The conductivity of bulk polysilanes is reported to occur via the migration of holes. Since there is considerable σ delocalization along the backbone of polysilanes these materials can be considered as a one-dimensitonal molecular wire, the backbone being the wire and the alkyl side groups acting as the insulator, Here, quantum mechanical calculations on the polysilane model compound Si17(CH3)36 aimed at elucidation of the electronic properties related to electrical conductance are presented.

    13. Synthetic hollow aluminophosphate microspheres (pages 931–935)

      Scott Oliver, Prof. Geoffrey A. Ozin and Dr. Neil Coombs

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071115

      Hollow aluminophosphate microspheres, based on mesolamellar surfactant bilayer aluminophosphate composite material, have been synthesized in polyethylene glycol by an alkylamine surfactant based method. The surface of the spheres displays patterns of surface impressions as well as fine morphological detail withi the spherical features.

  4. Research News

    1. Top of page
    2. Masthead
    3. Essay
    4. Communications
    5. Research News
    6. Talking Points
    1. High-spin alignment in π-conjugated Polyradicals: A Magnetic polymer (pages 937–941)

      Prof. Hiroyuki Nishide

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071116

      Extended dendritic, ladder, and cross-linked polyradical frameworks empolying π-conjugated backbones (e.g. see Fig.) show promise in the development of ferromagnetic polymers. Recent progress in this field is reviewed and the various classes of materials, for example polyacetylene-, or polyphenylenevinylene-based radicals, compared

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    2. Skeletons in the beaker: Synthetic hierarchical inorganic materials (pages 943–947)

      Prof. Geoffrey A. Ozin and Scott Oliver

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071117

      Hierarchical inorganic materials chemistry has been taken a step further by the “molecular beaker synthesis” of elaborately structured aluminophosphate morphologies. A unified surfactant-based cellular-type vesicle templating model is reported that is able to explain the origin of the macroscopic forms and surface patterns of synthetic inorganic-organic composite ultrastructures, many of which resemble those found in natural siliceous biomineralized structures.

  5. Talking Points

    1. Top of page
    2. Masthead
    3. Essay
    4. Communications
    5. Research News
    6. Talking Points
    1. Skeletons in the cupboard: Rediscovery in science (pages 948–951)

      Dr. Scott Oliver, Prof. Geoffrey A. Ozin and Dr. Linda A. Ozin

      Version of Record online: 15 SEP 2004 | DOI: 10.1002/adma.19950071118

      Are the ideas behind the recently published developments in biomimetic inorganic materials chemistry really as novel as they seem? This article is about rediscovery in science. The focus is on biomimetic inorganic materials chemistry and the 1872 classic published work of Pieter Harting, a Dutchman from Utrecht, on synthetic morphologies, particularly artificial calcareous formations. It would seem that one of the founding fathers of this burgeoning field of endeavor has (almost) been forgotten.

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