Advanced Materials

Cover image for Vol. 13 Issue 2

January, 2001

Volume 13, Issue 2

Pages 95–150

    1. Molecular Lubricants and Glues for Micro- and Nanodevices (pages 95–108)

      V. V. Tsukruk

      Article first published online: 24 JAN 2001 | DOI: 10.1002/1521-4095(200101)13:2<95::AID-ADMA95>3.0.CO;2-J

      Organic monolayers for nanolubrication and nanogluing are reviewed here, with a focus on organized molecular films from amphiphilic molecules, molecules with reactive ends, and functional oligomers. The interfacial properties of molecular coatings critical for their lubrication (see Figure) or adhesive performance at the nanoscale are discussed in the context of molecular structure and morphology of these coatings.

    2. Defect-Tolerant Single-Electron Charging at Room Temperature in Metal Nanoparticle Decorated Biopolymers (pages 109–113)

      C. A. Berven, L. Clarke, J. L. Mooster, M. N. Wybourne and J. E. Hutchison

      Article first published online: 24 JAN 2001 | DOI: 10.1002/1521-4095(200101)13:2<109::AID-ADMA109>3.0.CO;2-Y

      Gold nanoparticles assembled on a biopolymer template (see Figure) between metal electrodes on an insulating substrate are shown to exhibit unambiguous single electron charging effects that are found to depend on the nanoparticle properties and the geometrical contraints imposed by the biopolymer. The results support the idea of using nanoparticles in conjuction with biomolecular organization to produce nanoscale systems with defect-tolerant current–voltage behavior.

    3. Catalytic Growth of Zinc Oxide Nanowires by Vapor Transport (pages 113–116)

      M. H. Huang, Y. Wu, H. Feick, N. Tran, E. Weber and P. Yang

      Article first published online: 24 JAN 2001 | DOI: 10.1002/1521-4095(200101)13:2<113::AID-ADMA113>3.0.CO;2-H

      Patterned nanowire networks of photoluminescent highly crystalline ZnO nanowires (see Figure) have been produced via the vapor–liquid–solid mechanism using gold as catalyst. The diameters of the nanowires can be controlled by varying the thickness of the gold layer. The size of the wires has an influence on their emission characteristics (see also cover).

    4. “Hairy Tubes”: Mesoporous Materials Containing Hollow Self-Organized Cylinders with Polymer Brushes at the Walls (pages 117–121)

      R. Mäki-Ontto, K. de Moel, W. de Odorico, J. Ruokolainen, M. Stamm, G. ten Brinke and O. Ikkala

      Article first published online: 24 JAN 2001 | DOI: 10.1002/1521-4095(200101)13:2<117::AID-ADMA117>3.0.CO;2-1

      Hollow polymer cylinders in a polystyrene glass (see Figure) formed by self organization of hydrogen-bonded supramolecules are reported. Part of the supramolecular template can be conveniently removed after the structure has been formed allowing the tubes to be emptied without need for degradation or similar methods.

    5. Template Synthesis and Magnetic Behavior of an Array of Cobalt Nanowires Encapsulated in Polyaniline Nanotubules (pages 121–123)

      H. Q. Cao, Z. Xu, H. Sang, D. Sheng and C. Y. Tie

      Article first published online: 24 JAN 2001 | DOI: 10.1002/1521-4095(200101)13:2<121::AID-ADMA121>3.0.CO;2-L

      Metallic nanowires protected from oxidation and corrosion by a sheath of polyaniline have been prepared in arrays on an alumina membrane support. The cobalt wire/polyaniline tubule nanocomposite structures (see Figure), which are produced by using the polyaniline tubules as a template for the growth of the metal wires, have potential in applications such as magnetic antenna materials.

    6. Increased Efficiency and Controlled Light Output from a Microstructured Light-Emitting Diode (pages 123–127)

      B. J. Matterson, J. M. Lupton, A. F. Safonov, M. G. Salt, W. L. Barnes and I. D. W. Samuel

      Article first published online: 24 JAN 2001 | DOI: 10.1002/1521-4095(200101)13:2<123::AID-ADMA123>3.0.CO;2-D

      The use of Bragg scattering to increase the efficiency and control the spectrum and polarization of light from a polymer light-emitting diode (LED) is demonstrated. A lateral wavelength-scale microstructure in the form of a corrugation is integrated into the light-emitting layer and used to control the lateral modes (those parallel to the light-emitting layer) of the structure. Both photoluminescence and electroluminescence efficiencies can be enhanced in poly[2-Methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylenevinylene] (MEH–PPV) based devices.

    7. Crystal Structure of Epitaxial Quaterthiophene Thin Films Grown on Potassium Acid Phthalate (pages 127–130)

      S. Timpanaro, A. Sassella, A. Borghesi, W. Porzio, P. Fontaine and M. Goldmann

      Article first published online: 24 JAN 2001 | DOI: 10.1002/1521-4095(200101)13:2<127::AID-ADMA127>3.0.CO;2-Y

      Synchrotron X-ray diffraction at grazing incidence has led to the identification of a new crystal structure of quaterthiophene (4T, see Figure). Epitaxial growth of the oligothiophene, deposited by organic molecular beam deposition (OMBD), on a potassium acid phthalate (KAP) crystal substrate is demonstrated on the basis of the commensurability of the 4T crystal (ac diagonal) with the b-axis of the KAP crystal.

    8. The Core-Size Effect on the Mobility of Charge in Discotic Liquid Crystalline Materials (pages 130–133)

      A. M. van de Craats and J. M. Warman

      Article first published online: 24 JAN 2001 | DOI: 10.1002/1521-4095(200101)13:2<130::AID-ADMA130>3.0.CO;2-L

      The maximum one-dimensional mobility of charge within the insulated cores of columnarly stacked discotic molecules increases with increasing size (the number of C, N, and O atoms constituting the central aromatic macrocycle, see Figure) of the central core. This relationship can serve as a design criterion for discotic materials in future molecular electronic devices.

    9. Synthesis and Electrochemical Polymerization of New Oligothiophene Functionalized Cyclophanes (pages 133–136)

      L. Guyard, M. Nguyen Dinh An and P. Audebert

      Article first published online: 24 JAN 2001 | DOI: 10.1002/1521-4095(200101)13:2<133::AID-ADMA133>3.0.CO;2-9

      Oligothiophenes coupled to cyclophanes are shown to exhibit interesting optical properties. The molecule shown in the Figure is synthesized by dimerizing a substituted bithiophene using iron trichloride. The materials are thought to have potential in nonlinear optical and light-emitting diode applications.

    10. Controlled Growth of Cubic Cadmium Sulfide Nanoparticles Using Patterned Self-Assembled Monolayers as a Template (pages 136–139)

      C.-C. Chen and J.-J. Lin

      Article first published online: 24 JAN 2001 | DOI: 10.1002/1521-4095(200101)13:2<136::AID-ADMA136>3.0.CO;2-Y

      Spheres, rods, and wires are the most usual morphologies of semiconductor nanoparticles. Here, in contrast, cube-shaped crystals of cadmium sulfide (e.g., see Figure) are reported. The “nanocubes” are produced on self-assembled monolayers of alkanethiolates on gold, and the size of the cubes can be controlled through the use of different solvents during the synthesis.

    11. Self-Organized Superstructures of Fluorocarbon-Stabilized Silver Nanoparticles (pages 140–142)

      T. Yonezawa, S. Onoue and N. Kimizuka

      Article first published online: 24 JAN 2001 | DOI: 10.1002/1521-4095(200101)13:2<140::AID-ADMA140>3.0.CO;2-H

      Mesoscopic honeycomb structures (see Figure) and regular, hexagonally packed monolayers are produced when fluorocarbon-stabilized silver particles are cast onto solid substrates from flurocarbon solution. The structures formed are shown to depend on the concentration of the solution and the humidity of the atmosphere.

    12. Room-Temperature Deposition of Defect-Free Magnetite Film by Chemical Reaction from an Aqueous Solution (pages 142–145)

      M. Izaki and O. Shinoura

      Article first published online: 24 JAN 2001 | DOI: 10.1002/1521-4095(200101)13:2<142::AID-ADMA142>3.0.CO;2-9

      A defect-free magnetite (Fe3O4) film with a smooth surface has been prepared on a non-conductive glass substrate simply by immersing the substrate in an aqueous solution containing hydrous iron(III) nitrate and dimethylaminoborane at room temperature. The magnetite film is shown to have a spinel structure and to exhibit interesting magnetic properties.

    13. Solvothermal Reduction Synthesis of InSb Nanocrystals (pages 145–148)

      Y. Li, Z. Wang, X. Duan, G. Zhang and C. Wang

      Article first published online: 24 JAN 2001 | DOI: 10.1002/1521-4095(200101)13:2<145::AID-ADMA145>3.0.CO;2-Y

      Group III–V compound semiconductors are used widely in electronic and optoelectronic applications. Of this group of materials, indium antimonide is particularly well suited for use in high-speed devices as it has a small bandgap and the largest room-temperature carrier mobility. Here, a new method for the synthesis of InSb (and related GaSb) is presented that sidesteps many of the problems of current methods, for example, high temperatures, air stability, or general complexity.

    14. Catalytic Growth of Carbon Nanorods on a High-Tc Substrate (pages 148–150)

      L. Thiên-Nga, K. Hernadi and L. Forró

      Article first published online: 24 JAN 2001 | DOI: 10.1002/1521-4095(200101)13:2<148::AID-ADMA148>3.0.CO;2-M

      Copper particles generated during the reduction of a superconducting substrate are found to catalyze the formation of carbon nanorods from acetylene (see Figure). The nanorods consist of stacked graphite planes parallel to the substrate. While this technique will not suit large-scale production its study does provide insight into the decomposition and growth mechanisms when compared to similar reactions on other substrates.