bluuebunny/crossref_metadata_2025 huggingface dataset:
New polymer electrolyte nanocomposites: Melt intercalation of poly(ethylene oxide) in mica‐type silicates
Authors: Vaia Richard A. , Vasudevan S. , Krawiec Wlodzimierz , Scanlon Lawrence G. , Giannelis Emmanual P.
Published: May 2005

The electrochemical performance of polymer‐based batteries can be improved by the addition of inorganic fillers to the polymer electrolyte, giving composite polymer electrolytes. The use of polymer nanocomposites, where the dimensions of the filler particles are reduced, should lead to the improvement of the performance of the electrolytes. Here, the direct intercalation of poly(ethylene oxide) into Na⊕ and Li⊕‐exchanged layered silicates and the properties of the resulting nanocomposites is reported.
Second harmonic generation in ferroelectric liquid crystalline thiadiazole derivatives
Authors: Loos‐Wildenauer Martina , Kunz Stefan , Voigt‐Martin Ingrid G. , Yakimanski Alexander , Wischerhoff Erik , Zentel Rudolf , Tschierske Carsten , Müller Meike
Published: May 2005

Ferroelectric liquid crystals are of interest for applications in second order nonlinear optical experiments as they combine a thermodynamically stable polar structure with mobility. Low‐molecular weight‐(see Figure) and siloxane‐fixed FLCs are reportd which contain a donor‐acceptor π system in a heterocylic ring whic does not disturb the desired rod‐like shape of the molecules.

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Microwave‐assisted synthesis of aluminum nitride
Authors: Ramesh Peelamedu D. , Rao Kalva J.
Published: May 2005

Aluminum nitride is an important ad high‐cost ceramic materials used in the electronics industry due to its combination of thermal conductivity, high strength; low thermal expansivity, and low dielectric constant. A new, simple and attractive route to sbmicrometer AlN powder (see Figure) is reported based on the use of microwave radiation.

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Nanocomposite materials with controlled ion mobilityk
Authors: Ruiz‐Hitzky Eduardo , Aranda Pilar , Casal Blanca , Galván Juan C.
Published: May 2005

The intercalation or entrapment of oxyethylene compounds, crown ethers, and poly(ethylene oxide) into inorganic osts provides the opportnity to design and prepare nanocomposite maerials useful for membrane and solid electrolyte applications. Crown ethers incorporated into the membranes produced by intercalation can act as ion‐selective sensors. The field is reviewed and several recently developed applications described.
Polymeric solid‐state dye lasers
Authors: Sastre Roberto , Costela Angel
Published: May 2005

Solid matrices containing laser dyes have been used to produce practical tunable solid state dye lasers with advantages such as compactness, manageability, lack of toxicity and flammablity etc. Polymer matrices have suffered in the past from limited photostability. Recently, polymeric materials with a laser‐damage threshold comparable to that of inorganic glasses and crystals have renewed activity in the field. Progress is reviewed.
Synthesis of SiC and Si3N4: An overview
Authors: Rodríguez‐Reinoso Francisco , Narciso Javier
Published: May 2005

Silicon‐based structural ceramics, such as silicon carbide, silicon nitride and SiAlON exhibit an attractive range of properties, i.e. high strength, stiffness, and good wear and corrosion resistance, and are considered very appropriate materials for high‐temperature applications. Recent progress in the synthesis of oth powder and whiskers of these materials is reviewed.
Porous etching: A means to enhance the photoresponse of indirect semiconductors
Authors: Erné Ben H. , Vanmaekelbergh Daniël , Kelly John J.
Published: May 2005

A strategy for improving the photoresponse for junctions based on crystalline and polycrystalline semiconductors is presented. Porous etching is used to produce a layer (e.g., see Figure) within which the light is more effectively absorbed. By tailoring the porous layer, it is possible to ensure that the minority carriers, while generated deep within the semiconductor, are nevertheless able to reach the junction without recombining

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Single crystal ß‐Si3N4 fibers obtained by self‐propagating high temperature synthesis**
Authors: Rodriguez Miguel A. , Makhonin Nikolay S. , Escriña Juan A. , Borovinskava Inna P. , Osendi María I. , Barba Maria F. , Iglesias Juan E. , Moya José S.
Published: May 2005

The growth of single crystal β‐silicon nitride fibers (see Figure) several millimeters long through the application of self‐propagating high‐temperature synthesis is demonstrated. Advantages include the igh purity of the fibers obtained, the fact that the fibers are stable up to 2000°C, and the low cost of the SHS process

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2‐D. charge‐transfer molecules for second order nlo: off‐diagonal orientation
Authors: Nalwa Hari Singh , Watanabe Toshiyuki , Miyata Seizo
Published: May 2005

Second order nonlinear optical materials based on two‐dimensional charge‐transfer molecules rather than one‐dimensional molecules offer a number of advantages. For example, the 2‐D CT molecules retain their second order nonlinearity even if they are inclined away from normal to the substrate. This interesting class of new materials is presented and the factors influencing the performances of the materials, such as the incorporation of long π‐conjugated segments into the molecules, are discussed.
The materials research society
Authors: Phillips Julia M.
Published: May 2005

The 1995 president of the MRS describes recent progress for the Society including its affiliation with the 800 000‐member strong Federation of Materials Societies and its activities on the World Wide Web.
Precursor‐derived Covalent Ceramics*
Authors: Bill Joachim , Aldinger Fritz
Published: May 2005

The preparation of ceramic materials from preceramic compounds provides a means for the synthesis of new materials which cannot be obtained by conventional methods. An example is shown in the figure, which shows carbon‐fiber‐reinforced silicon carbide coated with silicon carbonitride prepared by dip‐coating the substrate with a slurry made of polyhydridomethylsilazane and silicon powder. Progress and applicational examples are reviewed

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On the electrochemical polymerization of acrylonitrile and n‐vinylpyrrolidone: new insight into the mechanism*
Authors: Jérǒme Robert , Mertens Marc , Martinot Lucien
Published: May 2005

The protection of metals against environmental attack can be achieved by coating the metal with a protective organic film. Poor adhesion of the organic film to the metal surface has, however, limited the success of this approach. Here it is demonstrated that polyacrylonitride can be elecrografted onto a nickel surface producing a strongly adherent film. The transformation of the organic film could also open the way to new polymer–metal composites.
Metamorphic materials: Restructuring siliceous mesoporous materials*
Authors: Khushalani Deepa , Kuperman Alex , Ozin Geoffrey A. , Tanaka Kaoru , Coombs Neil , Olken Michael M. , Garcés Juan
Published: May 2005

Effective tailoring of pore sizes in mesoporous molecular sieves (see Figure) has been achieved by a novel method involving the restructuring of the mesopores under mild aqueous conditions. A studyis reported aimed at elucidating the underlying chemistry. It is suggested that further investigation could provide insight into natural biomineral resorption and lead to materials with enhanced biocompatibility characteristics

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Liquid crystals based on 2‐fluoropyrimidine and ‐pyridine: synthesis, dielectric anisotropy and phase behavior*
Authors: Bremer Matthias
Published: May 2005

Polar liquid crystals with strongly positive dielectric anisotropies are of continuing interest to the display industry because they help to lower both the operating voltage and the total power consumption of LCDs in portable devices. Fluorinated heterocyclic materials (Figure, right, where MG is a mesogenic group) are shown here to exhibit improved mesophase properties and higher dielectric anisotropies than commonly used materials based on carbocyclic structures (Figure, left)

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Diversity as a program: Research center jülich
Authors: Munder Herbert , Simon Jens
Published: May 2005

The research center in Jülich is the largest of the 16 national research centers in the Federal Republic of Germany. This year, the center is 40 years old and has an anual budget of DM 485 million. In the early years the center concentrated on nuclear power‐related technologies but now research carried out at the center is very interdisciplinary and very diverse. The development of the center is described, the current research priorities presented and a view of an interdisciplinary materials research future is discussed.
Red‐orange electroluminescence with new soluble and air‐stable poly(naphthalene‐vinylene)s*
Authors: Tasch Stefan , Groaupner Wilhelm , Leising Günther , Pc Lin , Wagner Martin W. , Grubbs Robert H.
Published: May 2005

The optical and electronic properties of new soluble derivatives of poly(naphthalene‐vinylene) (PNV) with different length alkyl side groups are reported. Quantum efficiencies of up to 10% and power efficiencies of up to 0.02% have been attained from polymer‐LEDs based on these materials, and the polymers themselves are found to have a well‐defined chemical structure and exhibit little main‐chain stiffness.
High‐spin alignment in π‐conjugated Polyradicals: A Magnetic polymer
Authors: Nishide Hiroyuki
Published: May 2005

Extended dendritic, ladder, and cross‐linked polyradical frameworks empolying π‐conjugated backbones (e.g. see Fig.) show promise in the development of ferromagnetic polymers. Recent progress in this field is reviewed and the various classes of materials, for example polyacetylene‐, or polyphenylenevinylene‐based radicals, compared

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Skeletons in the beaker: Synthetic hierarchical inorganic materials*
Authors: Ozin Geoffrey A. , Oliver Scott
Published: May 2005

Hierarchical inorganic materials chemistry has been taken a step further by the “molecular beaker synthesis” of elaborately structured aluminophosphate morphologies. A unified surfactant‐based cellular‐type vesicle templating model is reported that is able to explain the origin of the macroscopic forms and surface patterns of synthetic inorganic‐organic composite ultrastructures, many of which resemble those found in natural siliceous biomineralized structures.
Synthesis and characterization of noble metal colloids in block copolymer micelles
Authors: Antonietti Markus , Wenz Eckhard , Bronstein Lyudmila , Seregina Mariana
Published: May 2005

Noble metal nanoparticles have been used for more than 2000 years. Applications currently under discussion include solar cell technology, catalysis, and nonlinear optics, where the enormous interfacial surface area of the colloidally dispersed metals and their unique electronic properties resulting from size quantization are exploited. The problem of the stability of these materials has been addressed by using amphiphilic copolymer micelles (see figure) as a nanostructured stabilization environment for the metal particles

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Properties of a hydroxydecyl‐functionalized polythiophene synthesized by the iron trichloride route
Authors: Casa Carlo Della , Bizzarri Paolo Costa , Salatelli Elisabetta , Bertinelli Franco
Published: May 2005

The solubility of polythiophenes substituted with a hydroxydecyl chain is found to be closely related to the polymerization conditions. The presence of the hydroxy function does not compromise the processability of the polymer into films nor the thermochromic and solvatochromic properties of the materials, although hydrogen bonding between macromolecules is thought to result in the restriction of solubility.
Engineering macromolecules self‐assembly: Molecular tubes vs. protein sheets via single amino acid substitutions in E. coli glutamine synthetase
Authors: Dabrowski Michael J. , Atkins William M.
Published: May 2005

Protein engineering provides a rationale for obtaining self‐assembling molecules which yield supramolecular arrays with varying quanternary architectures. An example is E. coli glutamine synthetase which can be manipulated to yield molecular tubes (see figure), cables, and hexagonally packed sheets

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Molecular dynamics of poly(γ‐octadecyl‐co‐methyl‐L‐glutamate) in ultrathin films and in the bulk
Authors: Blum Gernot , Kremer Friedrich , Juworek Thomas , Wegner Gerkard
Published: May 2005

Ultrathin layers of organic materials have great potential in advanced electronic and electro‐optical applications. Little is, however, known about the dielectric properties and molecular dynamics of Langmuir‐Blodgett film‐forming materials. Here, thin LB films of the title compound have been studied and their properties compared with those of the corresponding bulk materials.
Polymer films with a self‐organized honeycomb morphology
Authors: François Bernard , Pitois Olivier , François Jeanne
Published: May 2005

Porous polymer films with a regular arrangement of pores (see figure) with a narrow pore size distribution have recently been reported. The preparation of the films from a variety of star polystyrenes, micellar polystyrenes, and block copolymers, the mechanism of formation, and the potential applications of the materials are presented

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Versailles project on advanced materials and standards (VAMAS)
Authors: Early James G. , Rook Harry L.
Published: May 2005

Pre‐standards research—also called pre‐normative research—is necessary in the case of advanced materials because traditional tests are simply not suitable for these materials. The pace at which they enter the market place requires the rapid development of novel approaches to measurement and performance evaluation. VAMAS exists to remove barriers to trade in new technologies by addressing this need for research on which to base international standards. VAMAS's aims and organization are described, and a case study is outlined.
Self‐Assembling Frameworks: Beyond microporous oxides
Authors: Bowes Carol L. , Ozin Geoffrey A.
Published: May 2005

The self‐assembly of inorganic open framework structureshas blossomed during the 1990s. Following a short historical summary of the field, the main features of the major classes of microporous materials—cyanide open‐frameworks, chalcogenides, polychalcogenides and thio‐pnictates—are described. The Review concludes with a brief discussion of microporous structures of the main group (e.g. K8Sn25, see figure) and organic tecton frameworks.

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Hydrogen‐bonded pseudopolyrotaxanes
Authors: Asakawa Masumi , Ashton Peter R. , Hayes Wayne , Stoddart J. Fraser , Brown George R. , Menzer Stephan , White Andrew J. P. , Williams David J.
Published: May 2005

That supramolecular order on the nanometer scale in the crystalline state can be created by using both π–π stacking and hydrogen bonding interactions marks a significant development in the fields of crystal engineering and supramolecular chemistry. The design and construction of pseudorotaxane monomers (see figure) via self‐assembly is described, which are then further assembled to form linear pseudopolyrotaxane columns.

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Highly ordered materials with ultra‐low surface energies: Polyelectrolyte–surfactant, complexes with fluorinated surfactants
Authors: Antonietti Markus , Henke Susanne , Thünemann Andreas
Published: May 2005

Are non‐stick surfaces “the chemical analogue of the perpetual motion machine”, i.e., unattainable? Cheap and simple‐to‐produce systems with ultra‐low surface energy—and so on the way towards this ideal—are polyelectrolyte–surfactant complexes. Polarization micrographs of such systems involving fluorinated surfactants are presented (see also the cover picture) that reveal highly ordered microphases with high optical anisotropy that can be easily oriented. X‐ray and AFM data are also reported.
The metal‐on‐polymer interface in polymer light emitting diodes
Authors: Salaneck William R. , Brédas Jean‐Luc
Published: May 2005

The oxidation of calcium electrodes on polymer light emitting diodes (LEDs) can influence the lifetime of the LEDs by an order of magnitude. This finding illustrates how important the metal–polymer interface can be for LEDs. This aspect, which so far has usually been neglected, is investigated experimentally and interpreted in terms of quantum chemical modeling. It is shown that for all the metals considered (A1, K, Rb, Na, Ca) an interfacial region is formed between the metal and the polymer which behaves differently from the bulk.
Field‐effect transistor made with a sexithiophene single crystal
Authors: Horowitz Gilles , Garnier Francis , Yassar Abderrahim , Hajlaoui Riadh , Kouki Fayçal
Published: May 2005

For the fabrication of organic transistors sexithiophene (6T) is one of the most promising materials. Since high purity improves the transistor performance of 6T, the FET described here was built on an ultrapure sexithiophene single crystal, shown in the figure as a gray block. The characteristics of this transistor—better than those of FETs based on evaporated polycrystalline sexithiophene—are presented.

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Heterocyclic heptamers containing thiophene and pyrrole units: Synthesis and properties
Authors: Parakka James P. , Jeevarajan Judith A. , Jeevarajan Antony S. , Kispert Lowell D. , Cava Michael P.
Published: May 2005

Studies on septithiophenes are relatively rare compared to the available detailed investigations of sexithiophenes. The balance is redressed here by a report of the synthesis, electrochemistry and spectroscopic properties of a new α,ω‐disubstituted septithiophene and two pyrrole‐containing septithiophene and two pyrrole‐containing septithiophene analogues. Two different routes are described by which it was attempted to impart solubility in organic solvents to septithiophenes–one unsuccessful and one successful. Evidence of an unusual three‐electron transfer process is also presented.
Synthesis and aggregation of a phthalocyanine symmetrically‐functionalized with eight tetrathiafulvalene units
Authors: Blower Mark A. , Bryce Martin R. , Devonport Wayne
Published: May 2005

The first phthalocyanine derivative decorated with peripheral tetrathiafulvalene (TTF) units has been synthesized. The synthetic design strategy and the derivative's spectroscopic and electrochemical characterization are described. It is noted that the tendency of phthalocyanine units to assemble in solution is not prevented and also that the redox behavior of the appended TTF units is not hindered. The potential of TTF–phthalocyanines for molecular electronics is pointed out.
13C‐CPMAS NMR characterization and molecular dynamics of oligothiophenes in the solid state
Authors: Barbarella Giovanna , Zambianchi Massimo , Favaretto Laura , Rossini Sandra , Casarini Daniele
Published: May 2005

13C‐Cross polarization magic angle spinning (CPMAS) NMR is excellently suited to studying the solid‐state structure, conformation and molecular dynamics of oligothiophenes, but to date few data are available. The investigation reported here focuses on a homologous series of unsubstituted oligothiophenes. It is shown that 13C‐CPMAS NMR is capable of detecting changes in the symmetry properties of the oligothiophenes and of discriminating between odd‐ and even‐number oligothiophenes.
TMS: Spanning the Globe
Authors: Scott Alexander R.
Published: May 2005

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.
Photorefractive Polymers and Composites
Authors: Zhang Yue , Burzynski Ryszard , Ghosal Saswati , Casstevens Martin K.
Published: May 2005

Materials demonstrating a photorefractive effect are principal candidates for numerous applications, including high‐density optical data storage, optical image processing, phase conjugated mirrors and lasers, dynamic holography, optical computing, pattern recognition, etc. Considerable progress has been made in the research on photorefractive polymers and composite materials in the last few years. These materials have many advantages over inorganic photorefractive crystals, including large optical nonlinearities, low dielectric constants, low cost and ease of fabrication. A large number of materials, including those exhibiting an extremely large photorefractive effect, have been developed. In addition, a number of interesting phenomena particular to polymeric photorefractive materials have been reported and corresponding mechanisms have been proposed to account for these phenomena. Possible applications of these materials have been explored with the demonstration of a volume holographic storage device based on photorefractive polymers. This paper reviews the latest developments of the young and exciting field of polymeric photorefractive materials.
Polarized light emission from LEDs prepared by the Langmuir‐Blodgett technique
Authors: Cimrová Vera , Remmers Marcus , Neher Dieter , Wegner Gerhard
Published: May 2005

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.
Direct imaging of individual shape‐persistent macromolecules and their interaction by TEM
Authors: Wu Junhua , Lieser Günter , Wegner Gerhard
Published: May 2005

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.
Cathodic electrodeposition from aqueous solution of dense or open‐structured zinc oxide films
Authors: Peulon Sophie , Lincot Daniel
Published: May 2005

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.

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Skeletons on the brain
Authors: Mann Stephen
Published: May 2005

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.
Bones about skeletons
Authors: Ozin Geoffrey A.
Published: May 2005

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.
Dimeric Tetrathiafulvalenes: New electron donors
Authors: Otsubo Tetsuo , Aso Yoshio , Takimiya Kazuo
Published: May 2005

Organic conductors based on new classes of dimeric TTFs (e.g., see figure) are reviewed. The complexes have structures in some cases which are determined by inter‐TTF transannular interactions, leading to stretched, folded, and sandwich arrangements. These multi‐TTF materials have potential applications in the development of molecular electronic devices based on multi‐stage redox systems.

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Post‐polymerization functionalization of conducting polymers: Novel poly(alkylthiophene)s substituted with easily. Replaceable activated ester groups
Authors: Baüerle Peter , Hiller Markus , Scheib Stefan , Sokolowski Moritz , Umbach Eberhard
Published: May 2005

One‐step post‐polymerization‐functionalization of polythiophene is reported. Using the new method presented here a large variety of amines carrying, for example, sterically demanding or electronically sensitive functional groups can be attached to conducting‐polymer‐modified electrodes even under aqueous conditions. The Figure shows the starting material which is polymerized then functionalized. The following paper in this issue presents the use of these materials in the development of amperometric biosensors.

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Heterogenizing homogeneous catalysis
Authors: Petrucci Maria G. L. , Kakkar Ashok K.
Published: May 2005

A new method for heterogenizing homogeneous catalysts involving simple acid–base hydrolytic chemistry on inorganic oxide surfaces is described. It provides easy access to thin films containing terminal amine and phosphine donor ligands, which are precursors to a variety of oriented organometallic surfaces (see figure; L =CO, PR3). Opportunities for the development of tailor‐made active and selective catalysts are discussed.

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Electronically conducting polymers and activated carbon: Electrode materials in supercapacitor technology
Authors: Mastragostino Marina , Arbizzani Catia , Meneghello Luca , Paraventi Ruggero
Published: May 2005

Supercapacitors are now attracting much attention as battery‐complementary devices for applications requiring high operating power levels, such as in electric vehicle technology. Two types of supercapacitors with different modes of energy storage are currently under study: the double‐layer, and the redox. Electronically conducting polymers represent an interesting class of electro‐active materials for redox supercapacitors and can be applied in different configurations. Performance data for new and conventional devices are presented and compared to those of a double‐layer capacitor with activated carbon electrodes.
Gold nanoparticles in micellar poly(styrene)‐b‐poly(ethylene oxide) films—size and interparticle distance control in monoparticulate films
Authors: Möller Martin , Spatz Joachim P. , Roescher Arno
Published: May 2005

Block copolymer micelles have been employed as nanosized reactors in which single gold particles were formed. Films can be produced by a process consisting of four steps. Monolayers of hexagonally assembled micelles (see Figure and this month's cover) can be prepared with rather regularly arranged, size‐controlled Au nanoparticles. The method of preparation and the factors influencing control of the process are presented.

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Fabrication of single‐mode polymeric waveguides using micromolding in capillaries
Authors: Zhao Xiao‐Mei , Stoddart Alison , Smith Stephen P. , Kim Enoch , Xia Younan , Prentiss Mara , Whitesides George M.
Published: May 2005

Micromolding in capillaries (MIMIC) has been used to fabricate arrays of single‐mode polymeric waveguides from several classes of polymeric materials (epoxies, polyrethanes, and polyacrylates) supported on Si/SiO2 substrates. Waveguides clad with polymers having slightly lower refractive indices gave single‐mode output in the visible and near‐infrared regions. A typical waveguide structure exhibiting single‐mode behavior is shown in the Figure.

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Oxygen ion conductivity of platinum‐impregnated stabilized zirconia in bulk and microporous materials
Authors: Ziehfreund Andreas , Simon Ulrich , Maier Wilhelm F.
Published: May 2005

The effect of platinum impregnation on the ionic conductivity of yttria stabilized zirconia (YSZ) has been determined using complex impedance measurements in the frequency range 101–107Hz. Ionic conductivities and the corresponding activation enthalpies are reported for the temperature range 200–600°C. Platinum agglomerated at the grain boundaries of polycrystalline samples reduces ion transport across the intergranular zone. The evaporation and recondensation of YSZ and the addition of Pt results in porous materials with improved oxygen ion conductivity.
Liquid crystalline α, α‐difluorobenzyl phenyl ethers
Authors: Bartmann Ekkehard
Published: May 2005

Liquid crystalline compounds containing a difluoromethyleneoxy (CF2O) bridge, which increases the polarity, have been synthesized and investigated. The physical properties related to liquid crystal applications (i.e., phase transitions, viscosity, dielectric anisotropy, birefringence) are reported. The compounds shown unusually low viscosities in combination with mostly reasonable or good values of the other parameters, making them highly interesting for applications in modern display technologies.
The ISI journal analysis report ‘advanced materials’
Authors: Gregory Peter
Published: May 2005

The citation performance of journals such as Advanced Materials can now be analyzed in detail with the aid of a database available from the Institute of Scientific Information (ISI). Answer can be found to questions such as which papers have been cited the most, which authors are most consistently cited, and which institutions have been the most prolific; that is, which articles, by which authors, and from which countries or companies have been responsible for a particular journal's citation performance? Examples are given in the case of Advanced Materials
Organic transistors using α‐octithiophene and α, ω‐dihexyl‐α‐octithiophene: Influence of oligomer length versus molecular ordering on mobility
Authors: Hajlaoui Riadh , Fichou Denis , Horowitz Gilles , Nessakh Belkacem , Constant Mathieu , Garnier Francis
Published: May 2005

The efficiency of organic field‐effect transistors (OFETs) based on high‐purity α‐octithiophene (α‐8T) and its alkylated derivative DHα‐8T (see Figure) has been investigated, particular attention being paid to the influence of oligomer length, material purity, and film ordering on OFET performance, especially field effect mobility. The question of whether the mobility of the oligothiophenes keeps on increasing with chain length is discussed.

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Direct observation of chemical reactions in silica‐coated gold and silver nanoparticles
Authors: Mulvaney Paul , Giersig Michael , Ung Thearith , Liz‐Marzán Luis M.
Published: May 2005

The direct observation of chemical reactions of single particles in real time has been achieved using silver nano‐particles covered in a 10 nm silica shell (see cover). Transmission electron micrographs reveal how molecular iodine diffuses through the shell and reacts with Ag, giving AgI. A single AgI particle (mid‐gray) is shown to form on the surface of the silica while the Ag core shrinks.

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Preparation and utilization of molecularly imprinted silicas
Authors: Pinel Catherine , Loisil Patrice , Gallezot Pierre
Published: May 2005

Imprinted amorphous silicas tailored to adsorb selectively are presented. Their preparation–using molecular imprinting by the sol‐gel technique–is described and the influence of the conditions of preparation on the textures of the solids and on their molecular specificity discussed. Their degrees of enantiorecognition (using(–)‐menthol) are regiospecificity (using O‐cresol) are reported. The possibility of extension of this work to a large number of different molecular sizes and configurations is briefly considered.
Aromatic Poly(1, 3, 4‐Oxadiazoe)s as Advanced materials
Authors: Schulz Burkhard , Bruma Maria , Brehmer Ludwig
Published: May 2005

The specialized‐performance polymers poly(arylene‐1,3‐oxadiazole)s—see Figure for an example—have high‐value end uses based on their electronic, optical, and thermal properties. The syntheses, solid‐state structure, properties, and applications of poly(arylene‐1,3,4‐oxadiazole)s are reviewed.

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B/C/N Materials Based on the Graphite Network
Authors: Kawaguchi Masayuki
Published: May 2005

New semiconductors and host materials are expected to be found among newly synthesized boron/carbon/nitrogen (B/C/N) materials based on the graphite network. The synthesis, structure, and properties of such materials, including solid solutions, more‐ordered B/C/N hybrids, and compounds (e.g., BC3, C5N, BC2N, BC3N, BC4N, BC6N2H3), are reviewed. Particular attention is paid to their electrical properties, luminescenc characteristics, and intercalation chemistry, together with the application of B/C/N materials as a battery electrode matrix.
Multiplexing optical systems: Multicolor‐bifluorescent‐biredox photochromic mixtures
Authors: Tsivgoulis Gerasimos M. , Lehn Jean‐Marie
Published: May 2005

Optical memory systems that exhibit multiplexity and multifunctionality may allow high‐density storage and multiple addressing and readout. In a first step towards such systems, it is shown that two‐component mixtures of dithienylethene compounds (e.g., see Figure) can be switched reversibly between four different color states, using light as a trigger. The fluorescence of redox behavior increases the multiplexity (see front cover).

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Structures and properties of MeDTDM salts
Authors: Misaki Yohji , Taniguchi Masateru , Miura Takeshi , Fujiwara Hideki , Yamabe Tokio , Kawamoto Tadashi , Mori Takehiko
Published: May 2005

Unsymmetric tetrathifulvalene (TTF) derivatives, especially when fused with 1,3‐dithiol‐2‐ylidenes (DT‐TTFs), have yielded a large number of metallic salts and even some superconductors. The synthesis and characterization of teh methyl‐substituted DT‐TTF MeDTDM (see Figure) are reported as part of the search for new superconductors, the conductivities and X‐ray structure analysis of the new metallic salts being emphasized.

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Oligophenylenevinylenes for light‐emitting diodes
Authors: Goodson Theodore , Li Wenjie , Gharavi Ali , Yu Luping
Published: May 2005

Details of the structure–property correlation in organic light‐emitting diodes (LEDs) are reported for the oligophenylenevinylene (OPV) system. The electroluminescence (EL) characteristics of 6‐OPV (n equals; 2 in the Figure) and 10‐OPV (n equals; 4 in the Figure) are compared and an explanation is proposed for the shift and broadening of the EL spectra under different driving voltages.

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Magnetic field induced reversed (Negative) magnetization for electrochemically deposited Tc = 260 K Oxidized Films of Chromium Cyanide Magnets
Authors: Buschmann Wayne E. , Paulson Scott C. , Wynn Charles M. , Girtu Mihai A. , Epstein Arthur J. , White Henry S. , Miller Joel S.
Published: May 2005

Molecule‐based magnets with high ordering temperatures Tc (above room temperature) include some mixed‐oxide hexacyanometallates. The example studied here, Cr2.12(CN)6 · ½ H2O (the Figure shows its crystalline and amorphous phases), is shown to have Tc equals; 260 K and exhibit negative (reverse) magnetization. An explanation is suggested for this behavior and the temperature and field dependences of the magnetization.

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Crystallization of CaCO3 in the presence of PEO‐block‐PMAA copolymers
Authors: Marentette Joanne M. , Norwig Jochen , Stöckelmann Elnar , Meyer Wolfgang H.
Published: May 2005

How copolymers affect the crystallization of inorganic materials has been studied, using as an example the effect of poly(ethylene oxide)‐block‐poly(methacrylic acid) (PEO‐bl‐PMAA) on calcite (CACO3). It si shown that the presence of PEO‐bl‐PMAA can lead to a drastic alteration of the crystal habit of calcite, producing a different morphology as a result of the changed crystallization kinetics. It is hoped that this work will eventually lead to a high degree of control of crystallization in the laboratory, approaching that found in nature.
Solvent‐assisted microcontact molding: A convenient method for fabricating three‐dimensional structures on surfaces of polymers
Authors: King Enoch , Xia Younan , Zhao Xiao‐Mei , Whitesides George M.
Published: May 2005

Solvent‐assisted micro‐contact molding (SAMIM), a non‐photo‐lithographic technique for fabriation of patterned, quasi‐three‐dimensional structures on surfaces of many different polymers, is described. The basis of the technique–an embossing/molding process in which a solvent softens a polymer–is out lined and many examples are given. The Figure shows a polystyrene structure produced using SAMIM with acetone as the solvent.

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Shell mimetics
Authors: Ozin Geoffrey A. , Yang Hong , Sokolov Igor , Coombs Neil
Published: May 2005

The synthesis of mesoporous silica sell‐shapes, with spiral and gyroid forms and ornate surface designs (see the inside front cover for examples), is described. High‐resolutioin SEM, TEM, and AFM were used to establish the spatial relationship between the bulk and surface mesosstructure and the overall morphpology of the shell mimies. The various stages in the growth of the shell‐shapes are described, which create silicified shell forms with periodic mesopores but devoid of microcystalline order.
The crystallization of polar, channel‐type inclusion compounds: Property‐directed superamolecular synthesis
Authors: Hulliger Jürg , Rogin Peter , Quintel Andrea , Rechsteiner Peter , König Olaf , Wübbenhorst Michael
Published: May 2005

How can the efficiency of formation of polar materials be improved? The work presented ehre makes use of the concept of supramolecular synthons, resulting in an inclusion formation approach that produces a nearly four times higher yield of polar crystal structures than the crystallization of dipolar molecules alone. The xample of co‐crystallization of racemic all‐trans perhydrotriphenylene (PHTP) with linear acceptors or donors is analyzed, and it is suggested that thie “Property‐directed” synthesis has a potentially high degree of predictability.
Molecular Recognition of Organized Assemblies via hydrogen bonding in aqueous media
Authors: Paleos Constantinos M. , Tsiourvas Dimitris
Published: May 2005

Molecular recognition of non‐biological systems in aqueous media presents problems arising from the inherent difficulty of formation of host‐guest systems. Examples are given for recognition occurring at the air‐water interface—the most common type, where receptors from a monolayer at the interface (see Figure)—or in micelles or vesicles. The particular role of directional hydrogen‐bonding interactions is emphasized.

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A novel family of amorphous molecular materials containing an oligothiophene moiety as color‐tunable emitting materials for organic electroluminescent devices
Authors: Noda Tetsuya , Ogawa Hiromitsu , Noma Naoki , Shirota Yasuhiko
Published: May 2005

The color of light emitted by organic electroluminescent devices can be tuned between light blue and orange in the family of materials presented here simply by varying the conjugation length (n = 1 to 4, see Figure) of the oligothiophene moiety. The synthesis of the amorphous molecular materials and the optical behavior of single‐layer electroluminescent devices based on them—see also the cover—are described.

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Bioluminescent assay of D‐3‐hydroxybutyrate in serum
Authors: Raunio Raimo P. , Leivo Pekka V. , Kuusinen Anne M.
Published: May 2005

An enzymatic assay of D‐3‐hydroxybutyrate in which the hydroxybutyrate dehydrogenase reaction is coupled to the bacterial oxidoreductase—uciferase system is described. The bioluminescent assay is based on either, end‐point, or on initial velocity measurements. This simple and rapid assay requires a single serum sample of 10 μl. Its linear range covers two orders of magnitude from 10−6 mol/I upwards. This assay is suitable for the routine determination of D‐3‐hydroxybutyrate in human blood with good accuracy.
Factors affecting the measurement of chemiluminescence in stimulated human polymorphonuclear leucocytes
Authors: Harber Michael J. , Topley Nicholas
Published: May 2005

Optimum conditions were established for the generation and measurement of luminoldependent chemiluminescence (CL) in human polymorphonuclear leucocytes (PMNL) stimulated with a variety of particulate and soluble agents. Several factors had a particular influence on the kinetics of CL stimulated by the chemotactic peptide N‐formyl‐L‐methionyl‐L‐leucyl‐L‐phenylalanine (fMLP). Two peaks, both azide‐sensitive, were observed at 21°C and 25°C. but these increased in magnitude and merged t o give a single, early peak when the temperature was increased t o 37°C. Pre‐exposure of PMNL to a buffer containing calcium was essential for the expression of both phases of fMLP‐stimulated CL, while the second peak decreased dramatically if the cells were stored at 4°C for 4 hours before assay. In contrast, storage of PMNL at 4°C for up t o 8 hours in a buffer without divalent cations did not alter the kinetics or magnitude of CL induced by other stimuli, and had the benefit of minimizing the rate of cell aggregation. This study confirms that measurement of luminol‐dependent CL in stimulated PMNL is a useful analytical tool, but shows that careful attention t o experimental design is required t o ensure that the observed CL provides a true measure of the parameter under investigation.
A rapid enhanced chemiluminescent immunoassay for allergen‐specific IgE antibodies
Authors: Stiles Heather J. , Bicknell Helen J. , Matthews Jayne A.
Published: May 2005

An enhanced chemiluminescent immunoassay is described for the measurement of allergen‐specific IgE antibodies. The assay is demonstrated for pollen from four grass species. A comparison was made between results obtained by this method and those obtained by the radioallergosorbent (RAST) procedure; a high degree of correlation (r = 0.95) was found for D. glomerata specific IgE. The assay is rapid and can be carried out in under 1 hour. The advantages of the luminescent assay as compared with the RAST procedure are discussed.
Lampteromyces bioluminescence—1. Identification of riboflavin as the light emitter in the mushroom L. japonicus
Authors: Isobe Minoru , Uyakul Duangchan , Goto Toshio
Published: May 2005

The bioluminescence of the luminous mushroom, Lampteromyces japonicus, was studied by using the mushroom gills and also the luminous mycelia, the latter being cultured from the isolated spores and grown in a potato sucrose medium. The luminescence intensity of the mushroom gills and the cultured mycelia was measured in an aqueous suspension under various conditions. The original intensity was enhanced by exposing the luminous cells to oxygen for several hours or to acids or bases for a short period. This enhancement enabled measurement of their bioluminescence spectra which were identical to the fluorescence spectrum of riboflavin, having a maximum at 524 nm. The green fluorescent substance was extracted with cold water from the mushroom and it was identified as riboflavin by spectroscopic and chromatographic analyses. Riboflavin was concluded to be the light emitter of this mushroom.
Synthesis and chemiluminescence of copolymers of 5‐amino‐8‐vinyl‐phthalazine‐1, 4(2H,3H)‐dione with methyl methacrylate or styrene, and of α, ω‐bis[5‐amino‐phthalazine‐1,4 (2H,3H)‐dion‐]8‐yl alkanes [=α, ω‐bis(6‐luminyl) alkanes]: Investigations on an intramolecular ‘distance effect’
Authors: Gundermann Karl‐Dietrich , Lieske Dieter , Haase Brigitte , Baca Brigitte Hartmann‐Azanza
Published: May 2005

Oligomers of 5‐amino‐8‐vinyl‐phthalazine‐1,4(2H,3H)‐dione exhibit about 0.05% of the chemiluminescence quantum yield of the corresponding ‘monomer unit’, i.e. 5‐amino‐8‐ethyl‐phthalazine‐1,4(2H,3H)‐dione which has a similar quantum yield to luminol. The quantum yields of copolymers of 5‐amino‐8‐vinyl‐phthalazine‐1,4(2H,3H)‐dione (1a) with methyl methacrylate or with styrene increase up to 1000‐fold, relative to the quantum yield of oligomers of (1a). Thus the monomer units of methyl methacrylate or styrene appear to act as ‘spacers’ between the lumigenic groups.

α,ω‐Bis[(5‐amino‐phthalazine‐1,4(2H,3H)‐dion‐)8‐yl] alkanes show an analogue ‘distance’ effect: the chemiluminescence quantum yield increases with increasing alkane chain length.

As the fluorescence of the corresponding amino phthalates (which are intermediates in the synthesis of the phthalazine diones) is only slightly influenced by the distance between the lumigenic groups it is suggested that a mainly chemical ‘distance effect’ is working here: the smaller the intramolecular distance between the hydrazide groups the more inhibition exists in respect of the oxidative reaction producing the luminol‐type chemiluminescence.
Bioluminescent enzyme immunoassay for progesterone using monoclonal antibodies and glucose‐6‐phosphate dehydrogenase labels
Authors: Brochu Michèle , Carrié Marie‐Luce , Térouanne Béatrice , Bélanger Alain , Nicolas Jean‐Claude
Published: May 2005

Bacterial luciferase, NAD(P): FMN oxidoreductase and anti‐mouse immunoglobulin were co‐immobilized on Sepharose 4B. This reagent together with a progesterone glucose‐6‐phosphate dehydrogenase conjugate and various anti‐progesterone monoclonal antibodies was used to develop a non‐separation bioluminescent immunoassay for progesterone. This monoclonal antibody based assay was sensitive and reliable and using the tracer progesterone‐11‐acetate‐glucose‐6‐phosphate dehydrogenase, the majority of the monoclonal antibodies give a better sensitivity with this enzymatic tracer than that obtained with an iodinated tracer.

In a second assay design progesterone‐glutathione was co‐immobilized with bacterial luciferase and NAD(P): FMN oxidoreductase on Sepharose 4B and three monoclonal antibodies were labelled with glucose‐6‐phosphate dehydrogenase. With aqueous progester‐one standards, this assay gave comparable sensitivity to the bioluminescent enzyme immunoassay using the second antibody immunoadsorbant and to an RIA but was unsuitable for plasma samples.
Inhibition of luminol‐dependent luminescence and simultaneous generation of native luminescence of activated human polymorphonuclear leukocytes by addition of albumin
Authors: Roschger Paul , Graninger Wolfgang , Klima Herbert
Published: May 2005

Luminol‐dependent luminescence (LDL) and luminol‐independent, native luminescence (NL) of polymorphonuclear leukocytes were investigated with respect to the effects generated by the addition of albumin to the reaction medium. The cells were activated: (1) by simple surface attachment to a hydrophilic plastic, (2) by opsonized zymosan, (3) by phorbol myristate acetate, (4) by formylmethionyl‐leucyl‐phenylalaline. Both kinds of emissions were recorded simultaneously using a method of spectral discrimination. The addition of albumin resulted in an inhibition of LDL, which coincided with a generation of NL. The extent of the inhibition of LDL depended on the type of stimulus used. Maximum inhibition occurred with cells activated by attachment to plastic surfaces and minimum inhibition was observed with cells stimulated by opsonized zymosan. Different contributions of extracellularly released reactive oxygen‐species may be responsible for this. It appears possible to discriminate between intra‐ and extracellular sites of oxygen‐metabolites production using albumin simultaneously as extracellular quencher of LDL and as luminescent probe for NL.