Advanced Materials

Cover image for Advanced Materials

February 1997

Volume 9, Issue 2

Pages fmi–fmi, 102–181

  1. Masthead

    1. Top of page
    2. Masthead
    3. Book Reviews
    4. Articles
    5. Communications
    6. Research News
    7. Materials Forums
    8. Research News
    9. Conference Calendars
    1. Masthead (page fmi)

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090201

  2. Book Reviews

    1. Top of page
    2. Masthead
    3. Book Reviews
    4. Articles
    5. Communications
    6. Research News
    7. Materials Forums
    8. Research News
    9. Conference Calendars
  3. Articles

    1. Top of page
    2. Masthead
    3. Book Reviews
    4. Articles
    5. Communications
    6. Research News
    7. Materials Forums
    8. Research News
    9. Conference Calendars
    1. Laser Ablation of Doped Polymer Systems (pages 105–119)

      Dr. Thomas Lippert, Prof. Akira Yabe and Prof. Alexander Wokaun

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090203

      Laser Ablation for polymer processing can be extended to most known classes of polymers by the addition of dopants to sensitize the polymers to UV laser radiation. The Figure shows bubble formation in polymethylmethyacrylate doped with an alkyl-diaryl-triazene with the laser fluence increasing from left to right. The dopant/polymer systems that have been investigated so far are reviewed and a general scheme containing all relevant mechanisms is suggested. fig.

  4. Communications

    1. Top of page
    2. Masthead
    3. Book Reviews
    4. Articles
    5. Communications
    6. Research News
    7. Materials Forums
    8. Research News
    9. Conference Calendars
    1. Polarized electroluminescence from an oriented poly (3-alkylthiophene) langmuir–blodgett structure (pages 121–124)

      Dr. Alberto Bolognesi, Dr. Giuseppe Bajo, Dr. Jari Paloheimo, Dr. Toni Östergärd and Dr. Henrik Stubb

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090204

      Polarized electroluminescence (EL) from an oriented poly(3-alkylthiophene) structure is reported, which is a first step towards the fabrication of an organic light-emitting diode (LED) that emits polarized light. A multilayer structure is described that includes a Langmuir-Blodgett film of poly(3-decylmethoxythiophene), PDMT, in which the polyenic backbones are oriented along the dipping direction. The optical properties–absorption, EL, photoluminescence–and the IV curve for an ITO/PDMT/Al device are presented.

    2. Template-directed synthesis of aragonite under supramolecular hydrogen-bonded langmuir monolayers (pages 124–127)

      Dr. Arkadi L. Litvin, Dr. Suresh Valiyaveettil, Dr. David L. Kaplan and Dr. Stephen Mann

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090205

      The design of supramolecular templates to direct the synthesis of organized inorganic materials is illustrated for aragonite (CaCo3), which is metastable under ambient conditions but found in gallstones, fish otoliths, etc. Spreading of the template 5-hexadecyloxyisophthalic acid at the air/water interface is shown to result in the specific nucleation of aragonitc (see Figure) from supersaturated calcium bicarbonate solution without additives.

    3. Efficient blue LEDs from a partially conjugated Si-containing PPV copolymer in a double-layer configuration (pages 127–131)

      Frank Garten, Dr. Alain Hilberer, Dr. Franco Cacialli, Eddy Esselink, Yvonne van Dam, Dr. Bart Schlatmann, Prof. Richard H. Friend, Prof. Teun M. Klapwijk and Prof. Georges Hadziioannou

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090206

      Efficient blue electroluminescent devices based on a novel silicon-containing poly(P-phenylene) derivative are described. It is shown that the turn-on field and internal quantum efficiency can be improved by using a double-layer device configuration instead of a single-layer one and by the addition of a transport layer at the cathodic side. The combined study of electrical and optical properties on one hand and morphological aspects on the other is demonstrated to be a fruitful approach to the improved performance of organic electronics.

    4. Synthesis and characterization of highly efficient and thermally stable diphenylamino-substituted thiophene stilbene chromophores for nonlinear optical applications (pages 132–135)

      Dr. Alex K.-Y Jen, Dr. Yongming Cai, Dr. Peter V. Bedworth and Dr. Seth R. Marder

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090207

      Highly nonlinear chromophores with good thermal stabilities (> 250 °C) are required if organic polymeric materials are to be developed for electro-optical (EO) applications. The synthesis and characterization of highly efficient and thermally stable diphenylamino-substituted thiophene stilbenes (e.g., see Figure) are reported, one of which was used to form a high-EO-coefficient composite with a polyquinoline.

    5. Inherent interference-filter polymer light-emitting diodes (pages 135–138)

      Dr. Piotr Barta, Jonas Birgerson, Dr. Shuwen Guo, Dr. Hans Arwin, Prof. William R. Salaneck and Dr. Malgorzata Zagórska

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090208

      A global or “systems” approach to the design of polymer-based light-emitting devices is shown to be important for an understanding of the details of light emission from these devices. A self-interference-filter type of light-emitting device with a very narrow spectral output–a prerequires for many applications but difficult to realize because of the typically broad electroluminescence emission spectrum–is described, in which color selection is achieved by the appropriate combination of layer thickness and values of refractive index of the components of the device structure.

    6. Dipolar NLO-phores with large off-diagonal components of the second-order polarizability tensor (pages 138–143)

      Dr. J. Jens Wolff, Dr. Daniela Längle, Daniela Hillenbrand, Dr. Rüdiger Wortmann, Dr. Ralf Matschiner, Dr. Christoph Glania and Dr. Peter Kramer

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090209

      A new class of nonlinear optical chromophores (NLO-phores) with large off-diagonal components of the second-order polarization and remarkable transparency properties have been investigated. The synthesis and NLO characterization of a series of C2n symmetry benzene derivatives, such as that shown in the Figure, are described. The results of UV-vis, EFISH, hyper-Rayleigh scattering, etc., measurements are compared.

    7. Hybrid organic-inorganic electrodes: The molecular material formed between polypyrrole and the phosphomolybdate anion (pages 144–147)

      Dr. Pedro Gómez-Romero and Mónica Lira-Cantú

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090210

      Hybrid molecular electrodes, based on a conducting polymer matrix containing a dispersion of an electroactive inorganic component, are reported. The phosphomolydate anion, [PMo12O40]3⊖, is dispersed in polypyrrole to investigate cooperative phenomena between the components. The interactions are shown to influence the magnetic, electrical, photochemical and electrochemical properties of these composite materials.

    8. Replica molding using polymeric materials: A practical step toward nanomanufacturing (pages 147–149)

      Dr. Younan Xia, Dr. Jabez J. McClelland, Dr. Rajeev Gupta, Dr. Dong Qin, Dr. Xiao-Mei Zhao, Prof. Lydia L. Sohn, Dr. Robert J. Celotta and Prof. George M. Whitesides

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090211

      The reliable fabrication of nanostructures is polymer materials, i.e. structures with feature sizes below 100 nm, is an important goal if progress in the application of such materials in electronic, magnetic, and optical devices is to be maintained. Replica molding has been used extensively to produce micrometer sized features. Here, the technique is extended to the nanometer regime such as that shown in the figure. fig.

    9. A new method for chemical modification of conductive polypyrroles without destroying their conductivity (pages 149–153)

      Prof. Noboru Ono, Chikanori Tsukamura, Youta Nomura, Hideo Hironaga, Dr. Takashi Murashima and Dr. Takuji Ogawa

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090212

      The functionalization of conducting polypyrroles in high yields without the polypyrroles losing their conductivity is reported. The method is based on the use of substituted arenes as starting materials, onto which the pyrrole ring is ‘grown’. The resulting pyrrole rings have aryl groups substitued on the 3− and/or 4-positions. The aryl groups themselves can carry a wide range of substituents which can be selected in order to tune the properties of the materials. The substitued pyrolle monomers can be polymerized using standard procedures.

    10. Alteration of the electrochemistry of fullerene C60 in the presence of dioxygen: Formation of a redox-active polymeric film (pages 153–156)

      Dr. Krzysztof Winkler, Dr. David A. Costa, Prof. W. Ronald Fawcett and Prof. Alan L. Balch

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090213

      A new route to the formation of an electrochemically active film that contains fullerene units is reported. The method involves the reduction of C60 to its dianion in the presence of dioxygen and produces a film (see Figure) that is similar, but not identical to films prepared by the electrochemical reduction of C60O. This new method of fullerence polymerization therefore avoids the need for the tedious preparation and purification of C60O. fig.

    11. Ultrafine AIN and Al-AlN powders: Preparation by DC Arc plasma and thermal treatment (pages 156–159)

      Dr. Hongdong Li, Dr. Haibin Yang, Prof. Guangtian Zou and Dr. San Yu

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090214

      Pure, white, nanosized aluminum nitride powder in a wurtzite structure has been prepared using the DC are plasma method. Aluminum nitride is an important ccceramic material which exhibits high thermal conductivity, high hardness, good corrosion resistance, and low thermal expansivity. The most critical factors in the production of advanced ceramics are the purity and homogeneity of the starting powders. The new method allows the production of ultrafine, pure A1N and Al-A1N composite materials.

    12. Solid opalescent films originating from urethanes of cellulose (pages 159–162)

      Prof. Rudolf Zentel, Dr. Manfred Müiller and Dr. Harald Keller

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090215

      Opalescent films of ca. 100 cm2 (see Figure and this month's cover picture) based on a renewable resource, cellulose, have been prepared. The films are based on cholesteric, semi-interpenetrating networks which result from the crosslinking of lyotropic liquid crystalline phases of cellulose carbanilates in commercial acrylates. Photocrosslinking of the films at different temperatures allowing patterning.

  5. Research News

    1. Top of page
    2. Masthead
    3. Book Reviews
    4. Articles
    5. Communications
    6. Research News
    7. Materials Forums
    8. Research News
    9. Conference Calendars
    1. Nanocrystalline materials prepared through crystallization by ball milling (pages 163–166)

      Anit K. Giri

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090216

      The process of mechanical milling of amorphous precursors can be used to produce bulk quantities of material with fine crystalline nanostructures. Here, the process and the factors which influence the quality of the materials produced are reviewed. The crystallization induced by mechanical milling and thermal annealing are compared and it is suggested that the induction of crystallization by ball milling may be a promising technique for preparing soft magnetic materials in powder form.

  6. Materials Forums

    1. Top of page
    2. Masthead
    3. Book Reviews
    4. Articles
    5. Communications
    6. Research News
    7. Materials Forums
    8. Research News
    9. Conference Calendars
    1. Materials forum (page 166)

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090217

  7. Research News

    1. Top of page
    2. Masthead
    3. Book Reviews
    4. Articles
    5. Communications
    6. Research News
    7. Materials Forums
    8. Research News
    9. Conference Calendars
    1. Controlling the surface properties of high temperature superconductors (pages 167–173)

      Prof. Chad A. Mirkin, Feng Xu and Jin Zhu

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090218

      Molecular monolayer-based surface modification has been used extensively for three of the four important classes of electronic materials, namely metals, semiconductors, and insulators. In this article recent progress in the application of t. is technique, which is commonly called “self-assembly”, to the modification of the surfaces of high-Tc superconductors (e.g. see Figure) is reviewed.

    2. Self-oscillating gels (pages 175–178)

      Dr. Ryo Yoshida, Dr. Toshikazu Takahashi, Dr. Tomohiko Yamaguchi and Dr. Hisao Ichijo

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090219

      A polymer gel is crosslinked polymer network swollen in solvent. Some gels undergo abrupt volume changes by swelling–shrinking in response to external stimuli, such as temperature or electric field. Recently a new type of biometric gel has been developed which autonomously repeats its swelling-shrinking cycles periodically in a closed solution, without any external stimuli, similar to a beating heart muscle. The new materials and their rhythmical behavior are discussed.

  8. Conference Calendars

    1. Top of page
    2. Masthead
    3. Book Reviews
    4. Articles
    5. Communications
    6. Research News
    7. Materials Forums
    8. Research News
    9. Conference Calendars
    1. Conference Calendar (pages 179–181)

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19970090220

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