Advanced Materials

Cover image for Advanced Materials

February 1996

Volume 8, Issue 2

Pages fmi–fmi, 107–188

  1. Masthead

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Corrigendum
    6. Reviews
    7. Communications
    8. Research News
    9. Talking Points
    10. Book Reviews
    1. Masthead (page fmi)

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080201

  2. Essay

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Corrigendum
    6. Reviews
    7. Communications
    8. Research News
    9. Talking Points
    10. Book Reviews
    1. TMS: Spanning the Globe (pages 107–109)

      Alexander R. Scott

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080202

      The Minerals, Metals & Materials Society (TMS) can trace its roots back to 1871, when a group of metallurgists and mining engineers in Pennsylvania organized themselves with the aim of sharing professional knowledge and experience with their peers. The Executive Director of TMS outlines the structure and work of TMS today—which includes publishing, organizing meetings, and the provision of a computer network service—and describes what it offers its 13 000 members throughout the world in all areas of materials science.

  3. Reviews

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Corrigendum
    6. Reviews
    7. Communications
    8. Research News
    9. Talking Points
    10. Book Reviews
    1. Photorefractive Polymers and Composites (pages 111–125)

      Dr. Yue Zhang, Dr. Ryszard Burzynski, Dr. Saswati Ghosal and Dr. Martin K. Casstevens

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080203

      Photorefractive materials have numerous potential applications in optical data processing. Recent advances in polymer and composite photorefractive materials are reviewed, including the various materials classes that have been developed and new phenomena that have been discovered. The figure shows an example of a bi-functional chromophore that is used in photorefractive composite materials to reduce phase segregation.

  4. Corrigendum

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Corrigendum
    6. Reviews
    7. Communications
    8. Research News
    9. Talking Points
    10. Book Reviews
    1. You have free access to this content
      Red-orange electroluminescence with new soluble and air-stable poly(naphthalene-vinylene)s (page 125)

      Stefan Tasch, Dr. Wilhelm Grapner, Prof. Günther Leising, Dr. Lin Pu, Michael P. Wagaman and Robert H. Grubbs

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080204

  5. Reviews

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Corrigendum
    6. Reviews
    7. Communications
    8. Research News
    9. Talking Points
    10. Book Reviews
    1. Fast Li⊕ Conducting Ceramic Electrolytes (pages 127–135)

      Prof. Gin-ya Adachi, Dr. Nobuhito Imanaka and Dr. Hiromichi Aono

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080205

      The all-solid, lithium rechargeable battery, which if available would find many applications, is one reason for carrying out research into Li⊕-conducting solids. Fast Li⊕-conducting ceramic electrolytes are reviewed with regard to their electrical properties and crystal structure. Both non-oxide based ceramics and oxide materials are considered, and possibilities for further developments—e.g., the preparation of the electrolyte by thin film techniques—are pointed out.

  6. Communications

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Corrigendum
    6. Reviews
    7. Communications
    8. Research News
    9. Talking Points
    10. Book Reviews
    1. Alignment of single-crystal zeolites by means of microstructured surfaces (pages 137–139)

      Dr. Loris Scandella, Gunnar Binder, Dr. Jens Gobrecht and Dr. Jacobus C. Jansen

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080206

      Nanoscale devices based on zeolites require either thin films of single-crystalline zeolites or ordered arrangements of zeolite crystals. A novel technique—with potentially wide applications—is reported here that enables thousands of zeolite crystals to be ordered using a microstructured silicon surface. The figure shows zeolites oriented in two positions (marked A and B) in silicon grooves.

    2. Fabrication of arrays of channel waveguides by self-assembly using patterned organic monolayers as templates (pages 139–142)

      Enoch Kim, Prof. George M. Whitesides, Larry K. Lee, Stephen P. Smith and Prof. Mara Prentiss

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080207

      Complex arrays of channel waveguides can be easily fabricated by the new approach reported here, which is based on microcontact printing and self-assembly of solid, three-dimensional polymeric structures from liquid precursors. It shows that structures produced by the procedure described act as multi-mode optical waveguides, and suggestions are made for improvements following on from this demonstration of principle. Waveguides are important in communications, photonic sensors, and optical devices.

    3. Continuous yttria-stabilized zirconia fibers (pages 142–146)

      Dr. Bernd Clauss, Andrea Grüb and Prof. Wilhelm Oppermann

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080208

      Polycrystalline oxide fibers have not yet been exploited to their full potential, perhaps because of difficulties with processability. In the successful new route for the production of continuous yttria-stabilized zirconia fibers detailed here, ZrO2 particles sols are used as oxide-forming components. The fine-grained compact ceramic fibers of tetragonal zirconia polycrystals obtained 2 mol-% Y2O3 are shown in the figure.

    4. Polarized light emission from LEDs prepared by the Langmuir-Blodgett technique (pages 146–149)

      Dr. Vera Cimrová, Marcus Remmers, Dieter Neher and Gerhard Wegner

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080209

      Polarized light emission from polymer light emitting diodes (LEDs) is one step towards improved sources of background illumination for efficient liquid crystal displays. It is demonstrated that the fabrication of organic LEDs based on poly(p-phenylene)s by the Langmuir–Blodgett technique enables the polarization of the emitted light to be controlled. The ratio of the intensity of light polarized parallel and perpendicular to the dipping direction is the highest reported so far. Photoluminescence and electroluminescence spectra are presented and discussed.

    5. Direct imaging of individual shape-persistent macromolecules and their interaction by TEM (pages 151–154)

      Junhua Wu, Dr. Günter Lieser and Prof. Gerhard Wegner

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080211

      The possibility of addressing and probing individual chains of a macromolecule by near-field methods—of interest for micromechanics and molecular electronics—can be envisaged as a result of the findings presented here. It is demonstrated that individual shape-persistent synthetic macromolecules can be imaged by transmission electron microscopy within monolayers and that hairy rod macromolecules can be isolated in a matrix of a different material.

    6. Decoration of carbon nanotubes (pages 155–157)

      Dr. Thomas W. Ebbesen, Dr. Hidefumi Hiura, Dr. Margaret E. Bisher, Dr. Michael M. J. Treacy, Dr. Julie L. Shreeve-Keyer and Dr. Robert C. Haushalter

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080212

      Applications of carbon nanotubes, a unique material, are limited by the relative inertness of the carbon surface. A general method of overcoming this is proposed in which the surface is preoxidized, producing various groups on the surface. These surface groups then act as nucleation points. For example, in the electroless plating reaction the surface of the nanotubes becomes decorated with silver particles (see figure).

    7. Chirality in regioregular and soluble polythiophene: An internal probe of conformational changes induced by minute solvation variation (pages 157–160)

      Dr. Gérard Bidan, Dr. Stéphane Guillerez and Dr. Victor Sorokin

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080213

      Chirality has been used as an internal probe of structural changes accompanying micro-aggregation of a soluble regioregular poly(alkylthiophene). First, the synthesis of new polythiophenes having long alkyl chains is described. The UV/vis and circular dichroic spectroscopy are shown to indicate that the transformation of a disordered species in solution into an ordered one in a micro-aggregated state is a two-step process. Tentative proposals are made about the nature of the intermediate state, which, however, remains unclear.

    8. A single source approach to the synthesis of CdSe nanocrystallites (pages 161–163)

      Tito Trindade and Prof. Paul O'Brien

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080214

      Synthetic routes to semiconductor nanocrystallites have become of particular interest since nanoparticle devices have been constructed. The route reported here for CdSe uses a single source in tri-n-octylphosphine oxide instead of the hazardous metal alkyls conventionally employed. The characterization of the nanocrystallites (see figure) shows that they are crystalline, approximately spherical, and close to monodispersed.

    9. Chemical synthesis of nanocrystalline titanium and nickel aluminides from the metal chlorides and lithium aluminum hydride (pages 163–166)

      Joel A. Haber, Johanna L. Crane, Prof. William E. Buhro, Claire A. Frey, Prof. Shankar M. L. Sastry, John J. Balbach and Prof. Mark S. Conradi

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080215

      Aluminide intermetallics are potentially useful structural materials—provided their brittleness can be reduced. One possible method is the refinement of grain size to the nanometer level. Measurements of the mechanical properties are required in order to confirm this. The preparation described here is a general solution-based strategy for the chemical synthesis of nanocrystalline aluminide intermetallics. The results of sample characterization are presented and a two-step formation of the aluminide phase proposed.

    10. Cathodic electrodeposition from aqueous solution of dense or open-structured zinc oxide films (pages 166–170)

      Dr. Sophie Peulon and Dr. Daniel Lincot

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080216

      Direct electrodeposition of zinc oxide films is reported for the first time. That this method of preparation is suited to large-scale production could be important for applications of ZnO, e.g., in solar cells. In addition to a description of the preparation and properties of the films, it is shown that the morphology of the layer can be controlled, varying from compact to open (see figure) structures.

    11. Unified crystal chemical model of high-Tc superconductors: Complete chemical formulation and mechanism of generation of cooper pairs for K3C60 and La2 − xBaxCuO4 − δ (pages 170–172)

      Prof. José M. María

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080217

      A reliable quantitative physical theory of high-Tc super-conductivity is not yet available, partly because a suitable model of the chemical composition, structure, and bonding high-Tc superconductors (HTSCs) does not exist. Here the basic premise required for such a model is presented: that in the normal state of HTSCs there are electrons trapped in metal – metal bonds. Detailed chemical formulae (i.e., including metal-metal bonding electron) are obtained for the superconducting systems K3C60 and La2−xBaxCuO4 − δ and interpreted in terms of donor–acceptor electron charge transfer.

  7. Research News

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Corrigendum
    6. Reviews
    7. Communications
    8. Research News
    9. Talking Points
    10. Book Reviews
    1. Mapping the elemental distribution in sol-gel derived ceramics (pages 173–176)

      Dr. Carol S. Houk and Prof. Catherine J. Page

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080218

      Elemental dispersive x-ray (EDX) composition distribution mapping using a scanning electron microscope (SEM) provides information about samples that is complementary to that obtained from X-ray diffraction. Examples are given (e.g., Ba and Cu maps of YBa2Cu3O7 − δ, see figure) to demonstrate the usefulness of this technique in evaluating the homogeneity of sol-gel products and in elucidating elemental zoning (see also cover picture).

    2. Origin of the “ohmic” current in organic field-effect transistors (pages 177–179)

      Prof. Gilles Horowitz

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080219

      Efforts to improve organic field-effect transistors (OFETs) have so far concentrated mainly on their field-effect mobility, but another important parameter is the on–off ratio, i.e., the ratio of the saturation current at maximum absolute gate voltage (Vg) to that at zero Vg. It is shown how an understanding of the so-called “ohmic” current, which reduces this ratio, will perhaps lead to improved performances now it has been recognized that this current is connected with mobile dopants.

  8. Talking Points

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Corrigendum
    6. Reviews
    7. Communications
    8. Research News
    9. Talking Points
    10. Book Reviews
    1. Hierarchical inorganic materials (pages 181–182)

      Dr. Charles T. Kresge

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080220

      The synthesis of hierarchical inorganic–organic composites using biological design principles is a domain where materials chemists are usually out-smarted by Nature. The author summarizes and discusses the recent contributions made by the groups of Geoffrey Ozin in Toronto (Canada) and Stephen Mann in Bath (UK) to the generation of matter with a striking resemblance to the highly complex forms characteristic of inorganic biological structures.

    2. Skeletons on the brain (page 183)

      Prof. Stephen Mann

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080221

      Responding to “Skeletons in the Cupboard” (Adv. Mater.1995, 7, 948) and “Skeletons in the Beaker” (Adv. Mater. 1995, 7, 943), Stephen Mann presents his view of the connection between his work on biomineralization and that on microstructures by Pieter Harting in the last century. He outlines his perspective of the area, in particular the relationship between biomineralization and biomimetic synthesis of inorganic materials.

    3. Bones about skeletons (page 184)

      Prof. Geoffrey A. Ozin

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960080222

      The final word (at least for the moment) on biomimetic inorganic chemistry is given to Geoffrey Ozin, who stresses the importance of the work of Harting, arguing that Harting's original idea of assembling inorganic precursors in the presence of organics is still the common thread that runs through all modern syntheses of inorganic materials inspired by biological construction principles.

  9. Book Reviews

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Corrigendum
    6. Reviews
    7. Communications
    8. Research News
    9. Talking Points
    10. Book Reviews

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