Advanced Materials

Cover image for Advanced Materials

November 1996

Volume 8, Issue 11

Pages fmi–fmi, 881–944

  1. Masthead

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

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081101

  2. Essay

    1. Top of page
    2. Masthead
    3. Essay
    4. Review
    5. Communications
    6. Research News
    1. Increased publication frequency in 1997 (page 881)

      Dr. Peter S. Gregory

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081102

      Have you noticed any changes in Advanced Materials during the last two years? These include the introduction of different cover pictures, the availability of the contents lists on the World Wide Web, and the launch of CVD, which has appeared regularly every two months since July 1995. Some changes are also in store for 1997. Details are given in the essay, together with a quick review of recent developments, for example, changes in the pattern of submission of manuscripts.

  3. Review

    1. Top of page
    2. Masthead
    3. Essay
    4. Review
    5. Communications
    6. Research News
    1. Tools and strategies for Developing New Materials (pages 883–894)

      Turgut M. Gür

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081103

      The synergistic dependence of materials properties upon structure and processing is reviewed. Advanced synthesis techniques, controlled microstructure, compositional tuning and, simulation and theoretical prediction are considered in turn. These topics are illustrated with examples of recently developed materials: diamond thin films, fullerenes and carbon nanotubes, giant magnetoresistance multilayers, ternary nitride hard coatings, and carbon nitrides. The use of the “materials tetrahedron” is particularly emphasized.

  4. Communications

    1. Top of page
    2. Masthead
    3. Essay
    4. Review
    5. Communications
    6. Research News
    1. Selective construction of electrical connections using an organic charge-transfer salt (pages 897–899)

      Christian Gurtner and Prof. Michael J. Sailor

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081104

      The growth and “pruning” of electrical connections between two platinum wires by electrocrystallization of the charge-transfer salt TTFBrx is reported. Crystals not involved in the connection can be removed by electrochemical reduction (see Figure). This method is a step towards the fabrication of complex structures without the use of a photolithographic or morphologic template.

    2. A carbon nanotube/organic semiconducting polymer heterojunction (pages 899–902)

      Dr. Danilo B. Romero, Dr. Michel Carrard, Dr. Walter De Heer and Prof. Libero Zuppiroli

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081105

      An all-organic device based on carbon nanotubes and semiconducting polymers is of great interest for opto-electronic applications. A rectifying heterojunction formed by these novel materials is reported for the first time. The onset for nonlinear current injection is demonstrated to occur at an applied electric field more than on order of magnitude lower than for a semiconducting polymer/conducting oxide or metal heterojunction. The light sensitivity of the heterojunction was also investigated.

    3. High order and submolecular imaging of end-capped quinquethiophene on Ag(111) (pages 902–906)

      Andreas Soukopp, Kurt Glöckler, Prof. Peter Bäuerle, Dr. Moritz Sokolowski and Prof. Eberhard Umbach

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081106

      Ultrathin films of functionalized oligomers with well-defined chain and conjugation lengths are of interest for organic electronic devices. Using the example of end-capped quinquethiophene vapor-deposited onto a Ag(111) surface, it is demonstrated that highly ordered monolayers of chemisorbed oligomers can be obtained in very large defect-free domains. LEED and STM (see Figure) studies provide information about the geometric parameters, molecular structure, and quality of the layers.

    4. Ferroelectric liquid crystalline block copolymers (pages 906–909)

      Dr. Ana Omenat, Dr. Rifat A. M. Hikmet, Dr. Johan Lub and Dr. Paul van der Sluis

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081107

      Ferroelectric liquid crystal (LC) polymers have several advantages compared to low molecular weight ferroelectric LCs (as well as a few disadvantages). The synthesis, characterization, and physical properties of a ferroelectric LC homopolymer and a related new ferroelectric LC polymer system—consisting of a block copolymer with microdomain morphology—are reported. The nearly total absence of hysteresis indicates that the system is monostable, which could make such polymers suitable for display applications with active matrix addressing.

    5. Aligned ZrO2(c)-CaZrO3 eutectics grown by the laser floating zone method: Electrical and optical properties (pages 909–912)

      Dr. José I. Peña, Dr. Rosa I. Merino, Dr. Germán F. de la Fuente and Prof. Victor M. Orera

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081108

      Ceramic eutectics grown from the melt have great structural advantages compared to conventional ceramics and also properties that make them suitable for applications as electronic and optical materials. The preparation of ordered lamellar eutectics of ZrO2(c)[BOND]CaZrO3 is described and the macroscopic and engineering characteristics of the material reported. The Figure shows an optical micrograph of a transverse section obtained in the transmission illumination mode.

    6. Pulsed field gradient NMR studies of small molecule diffusion in amorphous microporous silicas (pages 912–916)

      Cordula Krause, Stephan Klein, Prof. Jörg Kärger and Prof. Wilhelm F. Maier

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081109

      The channel system is a new class of porous materials can be studied by a combination of catalytic results, simple physicochemical characterization, and physical investigations. The investigations described here include the physisorption of small probe molecules, pulsed field gradient (PFG) NMR of selected small molecules, and the effect of surface polarity on diffusivity. These techniques will be useful in the search for novel microporous materials—for which there is a growing need—as an alternative to zeolites.

    7. Rapid prototyping of complex structures with feature sizes larger than 20 μm (pages 917–919)

      Dr. Dong Qin, Younan Xia and Prof. George M. Whitesides

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081110

      A rapid, low-cost technique of microfabrication for feature sizes of 20 μm or more is described, which is useful for the rapid production of limited numbers of microsensor and optical structures. The pattern can be designed on a PC and printed out on transparent films of polymers using a commercial image-setting system. The Figure shows an SEM image of a relief pattern generated on photoresistant film using this method.

    8. Third-harmonic generation from regio-regular and regio-irregular poly(3-dodecylthiophenes). Dependence of χ(3) on conjugation length (pages 920–923)

      Prof. Thomas Bjørnholm, Dr. Daniel R. Greve, Dr. Tommy Geisler, Dr. Jan C. Petersen, Dr. Manikandan Jayaraman and Prof. Richard D. McCullough

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081111

      The third-order nonlinear optical susceptibility of regio-regular poly(3-dodecylthiophenes) is observed to be enhanced by a factor of 10 as compared to that of regio-irregular poly(3-dodecylthiophenes) when pumped at 1907 nm. The increase in the effective conjugation length from regio-irregular to regio-regular poly(3-dodecylthiophene) is estimated from linear absorption data and the reported absolute value measured at 1907 nm represents the nonlinear susceptibility of the most highly conjugated regio-regular polythiophene film measured to date.

    9. Deeply colored self-assembled multilayers of anionic DPP bolaamphiphiles and cationic polyelectrolytes (pages 923–926)

      Farnaz Saremi, Gabriele Lange and Prof. Bernd Tieke

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081112

      Self-assembled ultrathin multilayer films containing DPP or DTPP chromophores are reported. The preparation of the multilayers built up out of a DPP derivative and a cationic polyelectrolyte on a silanized glass slide is described (see Figure), followed by the characterization of their optical properties. The stability of the deep red (DPP) or yellow (DTPP) films makes them particularly suitable for technical applications.

    10. Supramolecular fibers from a liquid crystalline octa-substituted copper phthalocyanine (pages 926–928)

      Dr. Elizabeth J. Osburn, Dr. Albert Schmidt, Dr. Lai-Kwan Chau, Dr. Si-Ying Chen, Paul Smolenyak, Prof. Neal R. Armstrong and Prof. David F. O'Brien

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081113

      Supramolecular fibers—bundles of individual strands—result from the self-assembly of a novel octa-substituted copper phthalocyanine with benzyloxyethoxy side chains. The synthesis and self-assembly of the fibers are described and results from microscopy and X-ray characterization presented. It is shown that incorporation of aromatic groups in the side chains of phthalocyanines favors discotic mesophases with extended thermal stability, in addition to promoting the formation of supramolecular fibers.

    11. Biomimetic synthesis of cadmium sulfide-ferritin nanocomposites (pages 928–932)

      Dr. Kim K. W. Wong and Prof. Stephen Mann

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081114

      The chemical construction of dispersed CdS nanoparticles within the polypeptide cage of apoferritin is demonstrated to be possible by a multistep synthetic route, as shown schematically in the Figure. Ferritin-induced nucleation of CdS clusters (squares) is followed by reaction with excess sulfide to give CdS–ferritin. Such biocompatible nanoparticles might find uses as tunable photochemical agents for diagnosis, sensing, and drug delivery.

    12. Donor/acceptor-substituted phenylenevinylenes (pages 932–935)

      Gerrit Klärner, Carsten Former, Xiaoling Yan, Dr. Ranko Richert and Prof. Klaus Müllen

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081115

      The incorporation of donor/acceptor moieties into poly(p-phenylenevinylene) has been accomplished by a simple cation–anion coupling reaction. The reaction was used to create a series of oligomers, which were then investigated by dielectric spectroscopy in order to study strong dipole moments along the conjugated chain. The information obtained by this method should elucidate cooperative dipole–dipole interactions and help to improve the poling stability of polymers in nonlinear optical devices.

    13. Blue superradiance from neat semiconducting alternating copolymer films (pages 935–937)

      Hendrik Jan Brouwer, Dr. Victor V. Krasnikov, Dr. Alain Hilberer and Prof. Georges Hadziioannou

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081116

      Blue superradiant emission in thin polymer films with a low energy threshold, as reported here, offers hope for the possible development of solid-state electrically pumped polymer lasers. The absorbance, emission, and fluorescence spectra of the blue-light emitting copolymer poly[dimethylsilylene-p-phenylene-vinylene-(2,5-di-n-octyl-p-phenylene)-vinylene-p-phenylene] are presented and discussed. It is suggested that lasing in the superradiant regime occurs as a result of the combination of optically induced net gain and waveguiding in the thin film.

  5. Research News

    1. Top of page
    2. Masthead
    3. Essay
    4. Review
    5. Communications
    6. Research News
    1. Dyeing salt crystals for optical applications (pages 941–944)

      Prof. Bart Kahr, Dr. Sei-Hum Jang, J. Anand Subramony, Michael P. Kelley and Loyd Bastin

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19960081117

      Inorganic materials can encapsulate organic dye molecules in a variety of ways. Those considered here are simple inorganic salts that have adsorbed, oriented, and overgrown dyes during growth from solution, which promise spectroscopic and photonic applications. The Figure shows KH2PO4 crystals in which dyes carrying sulfonate or phosphate groups have been incorporated in the {101} growth sectors (see also the cover of this issue).

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