Advanced Materials

Cover image for Advanced Materials

December 1994

Volume 6, Issue 12

Pages fmi–fmi, 901–977

  1. Masthead

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Communications
    6. Research News
    7. Book Reviews
    1. Masthead (page fmi)

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061201

  2. Essay

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Communications
    6. Research News
    7. Book Reviews
    1. Cost 501, third round (pages 901–904)

      Dr. Florian Schubert

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061202

      The European Concerted Action Research Programs began in 1971. COST 501, which concentrates on materials problems in gas turbines, coal combustion and gasification, and diesel engines, is now entering its third round. The work package concept of the technical program is introduced and highlights of the second round are described. COST 501 provides a good illustration of what can be achieved in long-term collaborative research with realistic technical targets that are periodically defined by the industries involved.

  3. Reviews

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Communications
    6. Research News
    7. Book Reviews
    1. Crystal structures of Copper-Based High-Tc Superconductors (pages 905–921)

      Dr. Miguel Angel García Aranda

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061203

      Many copper-oxide-based superconducting compounds have been synthesized in recent years–currently more than 30 families are known, with superconducting transition temperatures up to 133 K. The structures of the various families are described, including La2CuO4, YBa2Cu3O7, single-layer superconductors, double-layer superconductors, and infinite layer materials (e.g., CaCuO2, as in the Figure).

    2. Characterizing Materials with Cyclic Voltammetry (pages 922–930)

      James F. Rusling and Steven L. Suib

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061204

      Cyclic voltammetry (CV) is a dynamic electrochemical method for measuring redox events. This summary of recent developments in the use of CV in materials science will be particularly useful for newcomers to the field. Following an introduction to the principles of CV, the current status of investigations of various types of materials are considered : microporous materials, semiconductors. polymer electrode coatings–with a view towards applications in sensors and catalysis–and surfactant films.

  4. Communications

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Communications
    6. Research News
    7. Book Reviews
    1. Photoluminescence of chromium(III)-doped silicoaluminophosphate with AFI structure (pages 931–934)

      Dr. Dirk Demuth, Prof. Kluus K. Unger, Dr. Ferdi Schüth, Prof. Galen D. Stucky and Dr. Vojisluv I. Srdanov

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061205

      Microporous crystalline aluminophosphates, especially substituted modifications, have many potential applications in optics. As a first step, an optimized hydrothermal synthesis is described that produces large, high optical quality, single crystals of Cr-containing silicoaluminophosphate (Cr-SAPO-5), see Figure, which, when calcined, exhibit photoluminescence.

    2. Photo- and electroluminescence efficiency in soluble poly(dialky1-p-phenylenevinylene) (pages 934–937)

      Dr. Emiel G. J. Staring, Robert C. J. E. Demandt, Dr. David Braun, Dr. Geert L. J. Rikken, Yves A. R. R. Kessener, Ton H. J. Venhuizen, Dr. Hans Wynberg, Dr. Wolter Ten Hoeve and Dr. Karin J. Spoelstra

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061206

      Efficient green electroluminescence from PPV derivatives that are readily processible in the conjugated state is reported. Derivatives of poly(p-phenylenevinylene), PPV, offer possible ways of controlling the emission color, facilitating processing, and enhancing the emission efficiency. The synthesis of soluble poly(dialky1-p-phenylenevinylene) is described and the dependence of the efficiency of photoluminescence and electroluminescence on the degree of conjugation 1s discussed.

    3. Efficient luminescence from zeolites (pages 937–941)

      Dr. Ulrich Kynast and Dr. Volker Weiler

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061207

      Zeolites as potential luminescent materials is a subject that has received little attention previously. The optical properties–UV emission and reflectance/absorbance spectra–of zeolites X and Y prepared with various degrees of Ce doping are described and an interpretation of the results is proposed based on the occupation of the various zeolitic coordination sites (see Figure).

    4. Broadband dielectric spectroscopy on an oxovanadium metallomesogen compound (pages 941–944)

      Prof. Miguel A. PéRez Jubindo, Dr. M. Rosario de la Fuente and Dr. Mercedes Marcos

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061208

      Metallo-organic mesogens have attracted much interest recently, with particular attention being paid to copper(II) and oxovanadium complexes because of their magnetic properties. A broadband dielectric spectroscopic study of a oxovanadium complex derived from a Schiff base is described and the results are compared with those from an EPR analysis. Consequences of the results for the dynamics are discussed.

    5. Crosslinkable polar siloxane copolymers for ion detection devices (pages 944–947)

      Harold Gankema, Ronny J. W. Lugtenberg, Dr. Johan F. J. Engbersen, Prof. David N. Reinhoudt and Prof. Martin Möller

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061209

      Functionalized polysiloxanes can be used as sensing membranes in ion-sensitive field effect transistors (ISFETs). A new 0 ue-Si and reproducible route for obtaining well-de-fined polysiloxane copolymers–the anionic copolymerization of cyclotetrasiloxanes with different side groups (one of which is shown in the Figure)–is reported and the characterization and use of the copolymers in CHEM-FETS described.

    6. Oxidation-state-dependent conformation in Cp*Mo(dmit)math image and antiferromagnetic ordering (TN = 8 K) of the neutral 17-electron complex Cp*Mo(dmit)math image (pages 948–952)

      Dr. Marc Fourrnigué and Dr. Claude Coulon

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061210

      Metal dithiolene complexes are attractive for the development of novel materials with extended electronic properties. The preparation of Cp*Mo(dmit)2 and its investigation by cyclic voltammetry, antiferromagnetic resonance, and electron paramagnetic resonance are described. Complexes of this class, i.e., with heteroatom substitution on the dmit dithiolene ligand, are shown to exhibit conformational flexibility directly related to the orbital occupancy.

    7. “Tailor-Made” and charge-transfer auxiliaries for the control of the crystal polymorphism of glycine (pages 952–956)

      Dr. Isabelle Weissbuch, Prof. Leslie Leisorowitz and Prof. Meir Lahav

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061211

      Crystal polymorphism is important because of the different physical and mechanical properties of the polymorphs. Based on a stereochemical approach to controlling crystal polymorphism using stereospecific nucleation inhibitors, auxiliaries have been designed for the precipitation of the yform of glycine (see Figure) from aqueous solutions. The ideas behind this work are presented, together with results.

    8. Inhibition of self-aggregation of α,ω-docosanediol into 3D Crystallites by “Tailor-Made” amphiphilic auxiliaries (pages 956–959)

      Dr. Ronit Popoiitz-Biro, Javek Majewski, Dr. Lev Murgulis, Dr. Sidney Cohen, Prof. Leslie Leiserovvitz and Prof. Meir Lahav

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061212

      The spontaneous aggregation of the bolaamphiphile α,ω-docosanediol into embryonic three-dimensional crystallites at the air-water interface can be inhibited by additives. A study with the aim of determining the necessary properties of such supplements is reported, which uses additives with molecular recognition properties and methods such as X-ray reflectivity, cryotransmission electron microscopy, and atomic force microscopy in order to detect structural changes at the nanometer level.

    9. Morphology-dependent spectroelectrochemical behavior of pbs nanoparticulate films grown under surfactant monolayers (pages 959–962)

      Dr. Yongchi Tian, Dr. Changiun Wu, Dr. Nicholas Kotov and Prof. Junos H. Fendler

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061213

      Template-dependent epitaxial growth of lead sulfide nanoparticulate films leads to three different morphologies, one of which is shown in the Figure. It is demonstrated that these structural differences are reflected in the spectroelectric, electric, and electrochemical properties, which is a step towards developing new colloid-chemical techniques for fabricating nanoparticulate-film-based semiconductor devices.

  5. Research News

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Communications
    6. Research News
    7. Book Reviews
    1. Porous silicon superlattices (pages 963–965)

      Dr. Stephan Frohnhoff and Dr. Michael G. Berger

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061214

      Porous silicon superlattices (PSSs) are a novel type of siliconbased heterostructures, in which the porosity varies periodically with depth. The two different types of PSSs and their techniques of formation are described, as are their optical properties and an example of an application: a Fabry-Perot-type interference filter. In combination with light emitting porous silicon, PSSs are promising candidates for optoelectronic applications based on silicon technology.

    2. Antiferroelectric liquid crystals (pages 966–970)

      Dr. Isa Nishiyama

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061215

      Antiferroelectric liquid crystals (AFLCs) were often first identified as antiferroelectric several years after the discovery of a new phase. This was the case for MHTAC (see Figure). The theory of the application of AFLCs as a tristable switch is outlined and the various types of AFLC materials described: low molecular mass (one of which is now commercially available), polymeric, and dimeric systems.

    3. Self-assembling phospholipid tubules (pages 971–974)

      Dr. Joel M. Schnur and Dr. Ranganathan Shashidhar

      Article first published online: 15 SEP 2004 | DOI: 10.1002/adma.19940061216

      Lipid-based tubules serve as models for the development of advanced materials based upon molecular self-assembly. The processes by which tubules are formed and how they are coated with metals (nickel in the Figure) or used as templates in order to increase the strength of the final material are described. Their electrical and magnetic properties are discussed.

  6. Book Reviews

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Communications
    6. Research News
    7. Book Reviews

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