Advanced Materials

Cover image for Advanced Materials

1997

Volume 9, Issue 14

Pages fmi–fmi, 1084–1124

  1. Masthead

    1. Top of page
    2. Masthead
    3. Materials Forum
    4. Essay
    5. Articles
    6. Communications
    7. Research News
    8. Book Reviews: Networking Polymers
    1. Masthead (page fmi)

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19970091401

  2. Materials Forum

    1. Top of page
    2. Masthead
    3. Materials Forum
    4. Essay
    5. Articles
    6. Communications
    7. Research News
    8. Book Reviews: Networking Polymers
    1. Materials Forum (page 1084)

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19970091402

  3. Essay

    1. Top of page
    2. Masthead
    3. Materials Forum
    4. Essay
    5. Articles
    6. Communications
    7. Research News
    8. Book Reviews: Networking Polymers
    1. Industrial chemistry in the information age (pages 1085–1086)

      Prof. Axel Kleemann

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19970091403

      Ullmann's Encyclopedia of Industrial Chemistry has a long tradition, going back to 1914, when the first German edition was published. How has this important publication, known by chemists throughout the world—not just in German-speaking countries—as an important source of reliable information, adjusted to changing times? How has it managed the transition to the electronic information age? These questions are answered by Professor Axel Kleemann, a member of the Editorial Board of Ullmann's, who also looks at the advantages offered by the new CD-ROM version.

  4. Articles

    1. Top of page
    2. Masthead
    3. Materials Forum
    4. Essay
    5. Articles
    6. Communications
    7. Research News
    8. Book Reviews: Networking Polymers
    1. Electrical and optical properties of Processable Polythiophene Derivatives: Structure-Property relationships (pages 1087–1094)

      Prof. Mario Leclerc and Dr. Karim Faid

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19970091404

      Control of the electrical and optical properties of different polythiophene derivatives can be achieved, to some extent, by adjusting the nature of their substituents. The effects of flexible side chains (increase in solubility, modification of the stability of the conducting state, induction of thermo-, iono-, photo-, or biochromism) such as alkyl or alkoxy moieties are reviewed and the promising self-doped polythiophenes (see Figure) discussed.

  5. Communications

    1. Top of page
    2. Masthead
    3. Materials Forum
    4. Essay
    5. Articles
    6. Communications
    7. Research News
    8. Book Reviews: Networking Polymers
    1. Excellent gelators for organic fluids: Simple bolaform amides derived from amino acids (pages 1095–1097)

      Prof. Kenji Hanabusa, Reo Tanaka, Dr. Masahiro Suzuki, Dr. Mutsumi Kimura and Prof. Hirofusa Shirai

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19970091405

      The gelation of organic solvents by low molecular weight gelators is an area of study still in its infancy. Difficulties in the design of universal gelators suitable for a wise variety of liquids arise because the self-aggregation of teh molecules strongly depends on the polarity of the solvent. The bolaform amides presented, derived from N-protected amino acids, are demonstrated to have gel-forming abilities for a range of organic solvents. The driving force responsible for gelation in this case is suggested and it is proposed that the amides form an extended molecular sheet in the liquids.

    2. Self-assembled PAMAM dendrimer films (pages 1097–1099)

      Dr. Simon A. Evenson and Prof. Jas Pal S. Badyal

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19970091406

      Self-assembly of starburst dendrimers into closely packed cells (see the optical micrograph in the Figure) is reported for generation 9.5 polyamidoamine (PAMAM) dendrimers solvent-cast onto hydrophilic silicon substrates. It is shown that on the microscopic scale the cells are made up of a complex network of intertwined dendritic microfibrils. Potential applications of such novel surfaces are suggested.

    3. Novel photorecording langmuir-blodgett films (pages 1099–1101)

      Dr. Minghua Liu, Dr. Kiminori Ushida, Dr. Hiroo Nakahara and Dr. Akira Kira

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19970091407

      A photocontrolled reaction of Langmuir-Blodgett (LB) films with transition metal ions is demonstrated to be suitable as the basis of a new method of photorecording. The setup required for recording is described and experiments on TARC18 and PARC18 films (a thiazolylazophenol and a pyridylazophenol derivative, respectively) are reported. Advantages compared to previously known techniques of photorecording in LB films are pointed out, for example, that differently colored states can be achieved with a single chelating reagent simply by changing the metal ions.

    4. Rewritable full-color recording on a thin solid film of a cholesteric low-molecular-weight compound (pages 1102–1104)

      Dr. Nobuyuki Tamaoki, Dr. Alexander V. Parfenov, Dr. Atsushi Masaki and Dr. Hiro Matsuda

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19970091408

      Rewritable full-color recording is potentially technologically important but has not yet been realized. A cholesteric low-molecular-weight compound (see Figure) is presented that, in the form of a thin film, displays iridescent colors at room temperature (see the cover picture of this issue) that can be recorded and erased repeatedly to form images by thermal treatment.

    5. Multiproperty molecular materials combining conductivity and second-order optical nonlinearities (pages 1105–1108)

      Dr. Pascal G. Lacroix and Dr. Keitaro Nakatani

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19970091409

      The combination of electrical and nonlinear optical (NLO) properties in one material is described for the tetracyanoquinodimethane (TCNQ) radical ion paired with N-methylstilbazolium-based chromophores. One of the resulting hybrid materials has a conductivity of 2.3 × 10−3 Ω−1 cm−1 and a second-harmonic generation efficiency 45 times that of urea. During the predicted transition from electronics to photonics, optoelectronics, which requires multiproperty materials such as those described here, will play an important role.

    6. Novel optical sensor materials based on solubilization of polar dyes in apolar polymers (pages 1108–1113)

      Dr. Gerhard J. Mohr, Dr. Tobias Werner, Dr. Ines Oehme, Dr. Claudia Preininger, Dr. Ingo Klimant, Dr. Barna Kovacs and Prof. Otto S. Wolfbeis

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19970091410

      Homogenous and fully transparent optical sensor layers have been prepared by pairing anionic indicator dyes with lipophilic quaternary ammonium halides (see Figure for an example) and then dissolving the pairs in an appropriate polymer. The synthesis of six ion pairs and the characterization of the resulting materials are described, along with the mechanisms responsible fo detection of several gascous species and ions.

    7. Large third-order nonlinear optical response from molecules with effective multidirectional charge-transfer transitions: New design of third-order nonlinear chromophores (pages 1113–1116)

      Daniel R. Greve, Steen B. Schougaard, Dr. Tommy Geisler, Dr. Jan C. Petersen and Dr. Thomas Biørnholm

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19970091411

      Enhanced values of the second molecular hyperpolarizability, γ, are reported for molecules that undergo significant multidirectional charge redistributions between the ground and excited states, e.g., charge is displaced from the periphery to the center, or vice versa, upon excitation, in during large changes in electric moments higher than dipole moments. The γ-values are compared with those for polyene-like molecules having a similar number of π-electrons. It is demonstrated that the “periphery-to-center charge-transfer” design concept is fruitful and should lead to new molecules with high γ-values.

  6. Research News

    1. Top of page
    2. Masthead
    3. Materials Forum
    4. Essay
    5. Articles
    6. Communications
    7. Research News
    8. Book Reviews: Networking Polymers
    1. Encapsulated electroactive molecules (pages 1117–1119)

      Prof. Christopher B. Gorman

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19970091412

      The role of a dendrimer as an encapsulating shell around small molecules or the dendrimer core itself are briefly outlined. It is shown that encapsulation by a dendrimer reduces the rate of electron transfer to or from a redox-active moiety incorporated in the core according to the degree of branching around the core. Development of this idea could lead to a molecular switch or an information storage device. The use of the properties of the core in order to obtain information about the shape, internal organization, and environment within a dendrimer is also outlined and an example given.

    2. Micropatterning fluid membranes (pages 1121–1123)

      Dr. Nick Ulman, Jay T. Groves and Prof. Steven G. Boxer

      Version of Record online: 29 OCT 2004 | DOI: 10.1002/adma.19970091413

      An application of photolithographic patterning is described for producing a self-assembled membrane that is fluid over some areas and immobilized or absent in others, as directed by the patterning on the support (see Figure). This is an important step towards forming a specific interface between living cells and silicon electronics. (Figure reprinted from Science1997 275, 651–653; ©1997 AAAS)

  7. Book Reviews: Networking Polymers

    1. Top of page
    2. Masthead
    3. Materials Forum
    4. Essay
    5. Articles
    6. Communications
    7. Research News
    8. Book Reviews: Networking Polymers

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