bluuebunny/crossref_metadata_2025 huggingface dataset:
Post-Westphalia and Its Discontents: Business, Globalization, and Human Rights in Political and Moral Perspective
Authors: Santoro Michael A.
Published: July 2012

This article examines the presuppositions and theoretical frameworks of the “new-wave” “Post-Westphalian” approach to international business ethics and compares it to the more philosophically oriented moral theory approach that has predominated in the field. I contrast one author’s Post-Westphalian political approach to the human rights responsibilities of transnational corporations (TNCs) with my own “Fair Share” theory of moral responsibility for human rights. I suggest how the debate about the meaning of corporate human rights “complicity” might be informed by the fair share theory. While I point out that Post-Westphalians and moral philosophers may have fundamental disagreements about basic concepts such as legitimacy, justice, and democratic deliberation, I conclude that the Post-Westphalians have made a major contribution to the expansion of the field by presenting business ethicists with an opportunity to inform and guide debates about the potential future course of transnational governance.
High-Leverage Finance Capitalism, the Economic Crisis, Structurally Related Ethics Issues, and Potential Reforms
Authors: Nielsen Richard P.
Published: July 2012

In this updated and revised version of his 2008 Society for Business Ethics presidential address, Richard Nielsen documents the characteristics and extent of the 2007–2009 economic crisis and analyzes how the ethics issues of the economic crisis are structurally related to a relatively new form of capitalism, high-leverage finance capitalism. Four types of high-leverage finance capitalism are considered: hedge funds; private equity-leveraged buyouts; high-leverage, subprime mortgage banking; and high-leverage banking. The structurally related problems with the four types of high-leverage finance capitalism converged in something of a perfect economic storm. Explanations for the crisis are offered in the context of the type of the high-leverage finance capitalism system that permitted and facilitated the economic crisis. Ethics issues and potential reforms are considered that may be able to mitigate the destructive effects of what Schumpeter referred to as the “creative destructive” effects of evolutionary forms of capitalism while realizing the Aristotelian economic ideal of creating wealth in such a way as to make us better people and the world a better place.
New Directions in Legal Scholarship: Implications for Business Ethics Research, Theory, and Practice
Authors: Hasnas John , Prentice Robert , Strudler Alan
Published: July 2012

Legal scholars and business ethicists are interested in many of the same core issues regarding human and firm behavior. The vast amount of legal research being generated by nearly 10,000 law school and business law scholars will inevitably influence business ethics research. This paper describes some of the recent trends in legal scholarship and explores its implications for three significant aspects of business ethics research—methodology, theory, and policy.
Accountability in a Global Economy: The Emergence of International Accountability Standards
Authors: Gilbert Dirk Ulrich , Rasche Andreas , Waddock Sandra
Published: July 2012

This article assesses the proliferation of international accountability standards (IAS) in the recent past. We provide a comprehensive overview about the different types of standards and discuss their role as part of a new institutional infrastructure for corporate responsibility. Based on this, it is argued that IAS can advance corporate responsibility on a global level because they contribute to the closure of some omnipresent governance gaps. IAS also improve the preparedness of an organization to give an explanation and a justification to relevant stakeholders for its judgments, intentions, acts and omissions when appropriately called upon to do so. However, IAS also face a variety of problems impeding their potential to help address social and environmental issues. The contribution of the four articles in this special section is discussed in the context of standards’ problems and opportunities. The article closes by outlining a research agenda to further develop and extend the scholarly debate around IAS.
On the Ease of (Dis)believing: The Role of Accessibility Experiences in Credibility Judgments
Authors: Ask Karl , Greifeneder Rainer , Reinhard Marc‐André
Published: July 2012

Credibility judgments are common and consequential in many applied settings. Although much research has addressed human observers' ability to discriminate true and deceptive statements, less is known about the psychological processes involved in such judgments. Here, it is proposed that the process of mustering evidence for or against credibility is reflected in a feeling‐based form (ease‐of‐retrieval) and that such feelings can be used as a basis for credibility judgments. The results of an experiment show, as predicted, that the perceived ease with which participants could identify clues strongly influenced credibility judgments. Ironically, mustering more clues in support of a truthful account lowered credibility judgments; in contrast, mustering more clues in support of a deceptive account increased credibility judgments. Mediation analyses suggest that this is because participants relied on a feeling‐based as opposed to content‐based judgment strategy. Practical implications are discussed, and theoretical issues regarding the process of credibility judgment are raised. Copyright © 2012 John Wiley & Sons, Ltd.
Confirmation Bias in General Aviation Lost Procedures
Authors: Gilbey Andrew , Hill Stephen
Published: July 2012

Pilots, students and orienteers completed three tasks in which they imagined that they were lost. For each task, participants were provided with a map and instructed to select one of three provided features to help them decide if they were at a certain (incorrect) location. One feature was unique to the correct location; the other two features were consistent with locations in both the incorrect location and the correct location. The unique feature was therefore the ‘correct’ choice to make. Only orienteers chose the unique feature at a rate significantly higher than chance; all other groups performed either at or worse than expected by chance. Attempts to increase the rate of disconfirming choices were largely ineffective. Findings suggest that when they are lost, both pilots and psychology students, but not orienteers, adopt a confirmatory approach to ascertain their location, which may put pilots who are already lost at even greater risk. Copyright © 2012 John Wiley & Sons, Ltd.
Ultrahigh Specific Capacitances for Supercapacitors Achieved by Nickel Cobaltite/Carbon Aerogel Composites
Authors: Chien Hsing‐Chi , Cheng Wei‐Yun , Wang Yong‐Hui , Lu Shih‐Yuan
Published: July 2012

Nickel cobaltite, a low cost and an environmentally friendly supercapacitive material, is deposited as a thin nanostructure of 3–5 nm nanocrystals into carbon aerogels, a mesoporous host template of high specific surface areas and high electric conductivities, with a two‐step wet chemistry process. This nickel cobaltite/carbon aerogel composite shows ultrahigh specific capacitances of around 1700 F g−1 at a scan rate of 25 mV s−1 within a potential window of −0.05 to 0.5 V in 1 M NaOH solutions. The composite also possesses an excellent high rate capability manifested by maintaining specific capacitances above 800 F g−1 at a high scan rate of 500 mV s−1, and an outstanding cycling stability demonstrated by a negligible 2.4% decay in specific capacitances after 2000 cycles. The success is attributable to the fuller utilization of nickel cobaltite for pseudocapacitance generation, made possible by the composite structure enabling well exposed nickel cobaltite to the electrolyte and easy transport of charge carriers, ions, and electrons, within the composite electrode.
Continuous Control of Charge Transport in Bi‐Deficient BiFeO3 Films Through Local Ferroelectric Switching
Authors: Kim Tae Heon , Jeon Byung Chul , Min Taeyoon , Yang Sang Mo , Lee Daesu , Kim Yong Su , Baek Seung‐Hyub , Saenrang Wittawat , Eom Chang‐Beom , Song Tae Kwon , Yoon Jong‐Gul , Noh Tae Won
Published: July 2012

It is demonstrated that electric transport in Bi‐deficient Bi1‐δFeO3 ferroelectric thin films, which act as a p‐type semiconductor, can be continuously and reversibly controlled by manipulating ferroelectric domains. Ferroelectric domain configuration is modified by applying a weak voltage stress to Pt/Bi1‐δFeO3/SrRuO3 thin‐film capacitors. This results in diode behavior in macroscopic charge‐transport properties as well as shrinkage of polarization‐voltage hysteresis loops. The forward current density depends on the voltage stress time controlling the domain configuration in the Bi1‐δFeO3 film. Piezoresponse force microscopy shows that the density of head‐to‐head/tail‐to‐tail unpenetrating local domains created by the voltage stress is directly related to the continuous modification of the charge transport and the diode effect. The control of charge transport is discussed in conjunction with polarization‐dependent interfacial barriers and charge trapping at the non‐neutral domain walls of unpenetrating tail‐to‐tail domains. Because domain walls in Bi1‐δFeO3 act as local conducting paths for charge transport, the domain‐wall‐mediated charge transport can be extended to ferroelectric resistive nonvolatile memories and nanochannel field‐effect transistors with high performances conceptually.
Functional Silica Nanoparticles for Redox‐Triggered Drug/ssDNA Co‐delivery
Authors: Ma Xing , Nguyen Kim Truc , Borah Parijat , Ang Chung Yen , Zhao Yanli
Published: July 2012

A mesoporous silica nanoparticle (MSNP) based co‐delivery system is developed in order to deliver simultaneously drug and single strand DNA (ssDNA) in a controlled manner. Negatively charged ssDNA as a model gene is immobilized onto the surface of positively charged ammonium‐functionalized MSNPs through electrostatic interaction, effectively blocking the loaded drugs within the mesopores of MSNPs. When the pre‐installed disulfide bond on the ammonium unit is broken by the addition of the reducing agent such as dithiothreitol or glutathione, the ssDNA network on the surface is freed, leading to the release of the loaded drug molecules from the mesopores. The cell investigations indicate that the functional nanoparticles have a very low cytotoxicity under the concentrations measured. The doxorubicin‐loaded and ssDNA‐coated nanoparticles show an enhanced cellular internalization, leading to a successful drug/ssDNA co‐delivery in vitro for significant apoptosis of Hela cancer cells as compared with that of free doxorubicin. The obtained experimental results indicate promising applications of the functional nanoparticles in cancer treatment.
Synthesis and characterization of perfluorinated acrylate–methyl methacrylate copolymers
Authors: Çanak Tuba Çakır , Hamuryudan Esin , Serhatlı İ. Ersin
Published: July 2012

A novel perfluorinated acrylic monomer 3,5‐bis(perfluorobenzyloxy)benzyl acrylate (FM) with perfluorinated aromatic units was synthesized with 3,5‐bis(perfluorobenzyl)oxybenzyl alcohol, acryloyl chloride, and triethylamine. Copolymers of FM monomer with methyl methacrylate (MMA) were prepared via free‐radical polymerization at 80°C in toluene with 2,2′‐azobisisobutyronitrile as the initiator. The obtained copolymers were characterized by 1H‐NMR and gel permeation chromatography. The monomer reactivity ratios for the monomer pair were calculated with the extended Kelen–Tüdos method. The reactivity ratios were found to be r1 = 0.38 for FM, r2 = 1.11 for MMA, and r1r2 < 1 for the pair FM–MMA. This shows that the system proceeded as random copolymerization. The thermal behavior of the copolymers was investigated by thermogravimetric analysis and differential scanning calorimetry (DSC). The copolymers had only one glass‐transition temperature, which changed from 46 to 78°C depending on the copolymer composition. Melting endotherms were not observed in the DSC traces; this indicated that all of the copolymers were completely amorphous. Copolymer films were prepared by spin coating, and contact angle measurements of water and ethylene glycol on the films indicated a high degree of hydrophobicity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Bulk grafting of poly(styrene‐alt‐maleic anhydride) onto preirradiated polyolefin membranes in supercritical carbon dioxide
Authors: Wang Yi‐Ming , Shao Song‐Hai , Lin Fei
Published: July 2012

To take advantage of the property of supercritical carbon dioxide as both a solvent and swelling agent, the bulk grafting of poly(styrene‐alt‐maleic anhydride) [P(MAH‐alt‐St)] onto preirradiated polyolefin membranes was performed by a combination of γ‐ray‐preirradiation‐induced graft copolymerization and supercritical fluid‐swollen polymerization. The trapped radicals on the polyolefin backbones were uniformly distributed by γ‐ray irradiation under a nitrogen atmosphere. Subsequently, these polymeric trapped radicals initiated the alternating copolymerization of styrene (St) and maleic anhydride (MAH) infused into the swollen polymer matrix with the aid of supercritical CO2. It was important that the graft copolymers were relatively pure without any contaminants, including homopolymers, monomers, and initiators. The experimental results show that the degree of grafting could be easily controlled. In addition, St/MAH could synergistically promote the bulk grafting process and strongly effect on the alternating trend; this was confirmed by element analysis and differential scanning calorimetry. Soxhlet extraction, X‐ray diffraction, and Fourier transform infrared spectroscopy indicated that the P(MAH‐alt‐St) was covalently bonded to the polymeric backbones. Scanning electron microscopy showed that the alternating graft chains were uniformly dispersed throughout the 5‐mm thickness of the polymer membranes on the nanometer scale. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Rheology and morphology of nanosilica‐containing polypropylene and polypropylene/liquid crystalline polymer blend
Authors: Foudazi Reza , Nazockdast Hossein
Published: July 2012

We studied the rheology and morphology of hydrophilic and hydrophobic silica containing polypropylene (PP) and PP/liquid crystalline polymer (LCP) blend. It was found that hydrophilic silica has higher tendency for aggregation and forms bigger aggregate size. The lower percolation threshold and the higher fractal dimension for hydrophilic silica are due to its stronger particle–particle interaction compared with the hydrophobic one. Although the hydrophobic silica has lower thickening capability and lower coalescence hindrance by aggregates, its presence at the interface of PP/LCP blend results in smaller droplet size and higher elasticity of hybrid samples in comparison to hydrophilic silica. These results confirm that the hydrophobic silica has a compatibilization capability for PP/LCP blend, whereas the hydrophilic silica mostly works as a thickening agent and suppresses the coalescence. We suggested that for comparison of different particulate compatibilizers, the elasticity of filled blend sample against filled matrix phase can be used in high and low frequency ranges. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
A new equation for predicting electrical conductivity of carbon‐filled polymer composites used for bipolar plates of fuel cells
Authors: Taherian Reza , Hadianfard Mohammad Jaffar , Golikand Ahmad Nozad
Published: July 2012

In this article, a statistical‐thermodynamic formula based on a new approach has been developed to predict electrical conductivity of carbon‐filled composites used for bipolar plate of proton exchange membrane fuel cell. In this model, based on percolation threshold phenomenon, it is assumed that the relationship between electrical conductivity of composite and filler volume fraction follows a sigmoidal equation. Afterwards, the four effective factors on composite conductivity including filler electrical conductivity, filler aspect ratio, wettability, as well as interface contact resistance are replaced upon constant parameters of sigmoidal function. In order to test the model, some single‐filler composites have been manufactured by using the phenolic resin as binder and graphite (G), expanded graphite (EG), and carbon fiber (CF) as fillers. The fitting quality is measured by R‐square, adjusted R‐square, SSE, and RMSE parameters. The results showed that there is a noteworthy agreement between the model and the experimental data. Compared to the other models, this model can be used for more types of fillers. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
A surface analysis of polypropylene/clay nanocomposites exposed to electron irradiation
Authors: Asadinezhad Ahmad , Khonakdar Hossein Ali , Jafari Seyed Hassan , Simon Frank , Wagenknecht Udo
Published: July 2012

The effects of electron irradiation in air at various doses on surface chemical composition of nanofilled polypropylene were explored by X‐ray photoelectron spectroscopy. An organically modified nanoclay ingredient along with a functional compatibilizer was employed for this purpose. The nanocomposite formation was confirmed by means of transmission electron microscopy, where in presence of compatibilizer, an exfoliated structure was brought about. Medium irradiation dose was established to be considerably effective in raising surface oxygen content, while at very high electron beam fluence, the ablation (etching) predominated. The optimal electron beam intensity was also found with respect to the extent of the functionalization. Various moieties of ether, ester, and alcohol characteristics were produced after exposure which could act as functional, active precursors being suitable for subsequent functionalization reactions. Furthermore, it could be understood that the electron irradiation spur organoclay migration toward surface layers. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Time‐series transcriptional profiling yields new perspectives on susceptibility to murine osteoarthritis
Authors: Poulet Blandine , Ulici Veronica , Stone Timothy C. , Pead Matthew , Gburcik Valentina , Constantinou Eleni , Palmer Donald B. , Beier Frank , Timmons James A. , Pitsillides Andrew A.
Published: July 2012

Objective

Chronological age is a powerful epidemiologic risk factor for osteoarthritis (OA), a multifactorial disease that is characterized by articular cartilage (AC) degradation. It is unclear from a molecular perspective how aging interacts with OA to produce this risk to AC integrity. To address this key question, we used in vivo time‐course analysis of OA development and murine interstrain variability in natural susceptibility to OA to examine changes in non–OA‐prone CBA mice versus OA‐prone STR/Ort mice, which develop disease that bears significant histologic resemblance to human OA. Through global transcriptome profiling, we attempted to discover the molecular signature linked with both OA vulnerability and progression.

Methods

Affymetrix Mouse Gene 1.0 ST Array profiles were generated from AC samples derived from CBA and STR/Ort mice at 3 different ages, corresponding to the stages prior to, at, and late after the natural onset of OA in the STR/Ort mice.

Results

We found that the OA in STR/Ort mice exhibited a molecular phenotype resembling human OA, and we pinpointed a central role of NF‐κB signaling and the emergence of an immune‐related signature in OA cartilage over time. We discovered that, strikingly, young healthy AC has a highly expressed skeletal muscle gene expression program, which is switched off during maturation, but is intriguingly retained in AC during OA development in STR/Ort mice.

Conclusion

This study is the first to show that AC chondrocytes share a high‐abundance gene‐expression program with skeletal muscle. We show that failure to switch this program off, as well as the restoration of this program, is associated with inappropriate expression of NF‐κB signaling pathways, skeletal muscle–related genes, and induction and/or progression of OA.
In vivo bone‐specific EphB4 overexpression in mice protects both subchondral bone and cartilage during osteoarthritis
Authors: Valverde‐Franco Gladys , Pelletier Jean‐Pierre , Fahmi Hassan , Hum David , Matsuo Koichi , Lussier Bertrand , Kapoor Mohit , Martel‐Pelletier Johanne
Published: July 2012

Objective

In vitro activation of the receptor EphB4 positively affects human osteoarthritis (OA) articular cell metabolism. However, the specific in vivo role of this ephrin receptor in OA remains unknown. We investigated in mice the in vivo effect of bone‐specific EphB4 overexpression on OA pathophysiology.

Methods

Morphometric, morphologic, and radiologic evaluations were performed on postnatal day 5 (P5) mice and on 10‐week‐old mice. Knee OA was induced surgically by destabilization of the medial meniscus (DMM) in 10‐week‐old male EphB4 homozygous transgenic (EphB4‐Tg) and wild‐type (WT) mice. Medial compartment evaluations of cartilage were performed using histology and immunohistochemistry, and evaluations of subchondral bone using histomorphometry, osteoclast staining, and micro–computed tomography.

Results

There was no obvious phenotype difference in skeletal development between EphB4‐Tg mice and WT mice at P5 or at 10 weeks. At 8 and 12 weeks post‐DMM, the EphB4‐Tg mice demonstrated significantly less cartilage alteration in the medial tibial plateau and the femoral condyle than did the WT mice. This was associated with a significant reduction of aggrecan and type II collagen degradation products, type X collagen, and collagen fibril disorganization in the operated EphB4‐Tg mice. The medial tibial subchondral bone demonstrated a significant reduction in sclerosis, bone volume, trabecular thickness, and number of tartrate‐resistant acid phosphatase–positive osteoclasts at both times assessed post‐DMM in the EphB4‐Tg mice than in the WT mice.

Conclusion

This is the first in vivo evidence that bone‐specific EphB4 overexpression exerts a protective effect on OA joint structural changes. The findings of this study stress the in vivo importance of subchondral bone biology in cartilage integrity.
Mechanisms of bone fragility in a mouse model of glucocorticoid‐treated rheumatoid arthritis: Implications for insufficiency fracture risk
Authors: Takahata Masahiko , Maher Jason R. , Juneja Subhash C. , Inzana Jason , Xing Lianping , Schwarz Edward M. , Berger Andrew J. , Awad Hani A.
Published: July 2012

Objective

Glucocorticoid (GC) therapy is associated with increased risk of fracture in patients with rheumatoid arthritis (RA). To elucidate the cause of this increased risk, we examined the effects of chronic erosive inflammatory arthritis and GC treatment on bone quality, structure, and biomechanical properties in a murine model.

Methods

Mice with established arthritis and expressing human tumor necrosis factor α (TNFα) transgene (Tg) and their wild‐type (WT) littermates were continually treated with GC (prednisolone 5 mg/kg/day via subcutaneous controlled‐release pellet) or placebo for 14, 28, or 42 days. Microstructure, biomechanical properties, chemical composition, and morphology of the tibiae and lumbar vertebral bodies were assessed by micro–computed tomography, biomechanical testing, Raman spectroscopy, and histology, respectively. Serum markers of bone turnover were also determined.

Results

TNF‐Tg and GC treatment additively decreased mechanical strength and stiffness in both the tibiae and the vertebral bodies. GC treatment in the TNF‐Tg mice increased the ductility of tibiae under torsional loading. These changes were associated with significant alterations in the biochemical and structural composition of the mineral and organic components of the bone matrix, a decrease in osteoblast activity and bone formation, and an increase in osteoclast activity.

Conclusion

Our findings indicate that the concomitant decrease in bone strength and increase in bone ductility associated with chronic inflammation and GC therapy, coupled with the significant changes in the bone quality and structure, may increase the susceptibility of the bone to failure under low‐energy loading. This may explain the mechanism of symptomatic insufficiency fractures in patients with RA receiving GC therapy who do not have radiographic manifestations of fracture.
Optical Spectra of Hexahalogeno‐Antimony (III) Complex Compounds
Authors: Schmidtke Hans‐Herbert , Krause Barbara , Schönherr Thomas
Published: July 2012

Complex compounds of SbX3−6 (X = Cl, Br) with alkylammonium counter ions were prepared and optically investigated by recording absorption spectra from materials in KBr discs, thin films and in solution. Emission spectra are measured from powder samples. The spectra exhibit the band patterns and temperature dependences known from other s2 systems which are characterized by Jahn‐Teller effects in the excited states of threefold orbital degeneracy. For the first time also the B band has been observed to be split in the absorption spectrum of an Sb(III) system which is attributed to vibronic coupling of the Γ−5(3P2) level to the τ2g Jahn‐Teller active mode.
Phase Behavior of Ionic Microemulsions
Authors: Lekkerkerker H. N. W. , Kegel W. K. , Overbeek J. Th. G.
Published: July 2012

Non‐polar oils and water can form thermodynamically stable quasi‐homogeneous (colloidal) mixtures (called microemulsions) in the presence of relatively large amounts (several %) of ionic surfactants. If the surfactant contains a single hydrocarbon chain (e.g. Sodium Dodecyl Sulphate) the presence of a non‐ionic cosurfactant (e.g. hexanol) and electrolyte (concentration of the order 0.1 M) is essential. With a double chain surfactant (e.g. Aerosol OT) the cosurfactant can be missed. At increasing concentrations of electrolyte and/or cosurfactant the nature of the microemulsion changes from droplets of oil in water via a presumably bicontinuous pattern to droplets of water in oil. It should be obvious that thermodynamic stability requires the interfacial tension between water and oil to be low (order of 0.01‐0.1 mN m−1) so that the dispersion entropy can offset the interfacial free energy. At these low interfacial tensions the influence of curvature on the interfacial tensions becomes important. It turns out that a given amount of surfactant (and co‐surfactant) can only disperse a limited amount of oil in water or of water in oil or of water and oil into one another and therefore a microemulsion may be in equilibrium with non colloidal oil and/or water phases. In the bicontinuous microemulsion oil and water may have a geometrically irregular interface or they may form lamellae of more or less constant thickness or other structures, such as a “molten cubic phase”. These equilibria lead to very interesting, but rather complicated phase diagrams. It will be discussed by what mechanisms the various components of the mixture influence the interfacial tension and promote the stability of the microemulsion and how this depends on the chemical nature of the components.
Morphological Thermodynamics of Microemulsions
Authors: Wagner Herbert
Published: July 2012

This note drafts a model where the thermodynamics of microemulsions is manifestly related with global morphological features of surfactant monolayers. The thermostatistics is governed by the competition between the surface tension of the monolayers and a topological energy encoded in the Euler characteristic. The model phase diagrams reproduce typical features of real microemulsions.
Optical Methods for Studying Microemulsions and Microemulsion Interfaces
Authors: Langevin D.
Published: July 2012

Optical methods are particularly interesting to study colloidal systems. They are extremely varied, they can probe both bulk and surface properties and they introduce little perturbation. One of the best known methods is light scattering. When applied to bulk samples, the method can give information about dispersion sizes, interactions between dispersed objects, type of organization in the case of ordered dispersions, critical behaviour, etc. Less widely known is the surface light scattering method, which leads to the determination of surface tension, and in some cases, surface elasticity and viscosity. Many other methods are available: Forced Rayleigh scattering and Florescence recovery after fringe pattern photobleaching (FRAP) probe self‐diffusion, Electrical birefringence is sensitive to non‐spherical objects or to aggregates and to their lifetimes. Surface methods such as Reflectivity or Ellipsometry are sensitive to the surface layer composition and to its roughness. More elaborated methods such as Second Harmonic generation or Infrared and Raman spectroscopy at surfaces give more detailed information about interfacial structures, but have not yet been applied much to microemulsion systems. In the following, we will describe the first methods and illustrate their potential applications for microemulsions with various experimental results obtained in our laboratory.
Kinetics and multilayering in the adsorption of polyelectrolytes to a charged surface
Authors: Schlenoff Joseph B. , Li Ming
Published: July 2012

The kinetics of radiolabeled poly(styrene sulfonate) adsorbing at a positively‐charged surface were determined using a surface‐charged plastic scintillator as substrate. In situ measurements indicate diffusion‐limited adsorption with the final adsorbance dependent on the solution concentration of polyelectrolyte. An absence of self‐exchange of unlabeled for labeled polymer suggests a thermodynamically irreversible process, at least for highly‐charged polymers on highly‐charged surfaces in the weak screening limit. Charge compensation of sulfonate was determined by displacement of labeled calcium (45Ca2+) probe ions. Compensation is complete for surface sites and only partial for interior sulfonates. The use of radiometric techniques facilitates studies of polyelectrolyte multilayer formation.
The influence of ionic charges on the structural and dynamical behavior of O/W microemulsion droplets
Authors: Gorski N. , Gradzielski M. , Hoffmann H.
Published: July 2012

An O/W microemulsion system has been investigated where the droplet size can be controlled via the concentration of cosurfactant (1‐hexanol). In that system the charge density of the droplets was varied by substitution of the original nonionic surfactant by a cationic surfactant. SANS measurements showed that the droplet radii are unaffected by the charging process, whereas the polydispersity decreases with increasing charge density. SANS and also static light scattering experiments are well described by a simple electrostatic model, which renders this droplet system a good model system. In contrast to that the diffusion coefficient shows a somewhat more complicated behavior. It increases strongly with rising ionic content but goes through a maximum around 3 mol% ionic surfactant and then decreases again. The magnitude of the increase and the position of the maximum are well described by theory, whereas the steepness of the decrease at still higher ionic surfactant content is not accounted for.
Photochemistry in porous materials III: Oxygen quenching of the fluorescence of fluoranthene adsorbed on silicagel of uniform pore size
Authors: Springob C. , von Bünau G. , Wolff T. , Schüth F.
Published: July 2012

The luminescence quenching reaction of fluoranthene by molecular oxygen on MCM‐41, a silicagel of uniform pore size, was studied at room temperature by time‐resolved and steady‐state fluorescence spectroscopy. The quenching reaction is well described by the Langmuir‐Hinshelwood‐(LH)‐model. By applying this model to the experimental results rate constants of the quenching reaction, equilibrium constants of oxygen adsorption, rate constants of oxygen desorption and heats of oxygen adsorption were derived.
Thermal unimolecular decomposition of acetic anhydride in the gas phase
Authors: Akao M. , Saito K. , Okada K. , Takahashi O. , Tabayashi K.
Published: July 2012

The thermal decomposition of acetic anhydride has been investigated behind incident and reflected shock waves at temperatures between 750 K and 980 K. The decomposition was monitored by vacuum‐UV absorption and IR emission. We confirmed that the decomposition proceeds to yield ketene and acetic acid with the first order reaction rate. Arrhenius parameters, for the rate constant were log(A/s−1) = 11.8 and Ea = 138 kJ/mol in our temperature region. Since the rate data evaluated in this work coincided with an extrapolation of the previous data, an Arrhenius expression which covers a wide temperature range from 470 K to 980 K was re‐evaluated as k = 1012.2 exp (−145 kJ/mol−1/RT) s−1

An ab initio MO calculation showed that the most probable reaction path is the concerted elimination through a 6‐center transition state. The potential barrier height for this path was evaluated to be 156 kJ/mol at the MP4(SDTQ) level.
Dynamics of strong and fragile glass formers and a scaling procedure for the temperature dependence of the viscosity
Authors: Rössler E. , Kudlik A. , Hess K.‐U. , Dingwell D. B. , Sokolov A. P. , Novikov V. N.
Published: July 2012

We review results from Raman scattering experiments on different types of glass formers which have been analysed in order to describe the fast relaxations occurring above Tg. Both fragile and strong glass formers exhibit similar dynamics which can be qualitatively reproduced by mode coupling theory (MCT). In particular, a crossover temperature Tc can be extracted where Tc>Tg. Quantitatively, deviations from the MCT predictions are larger, the stronger the glass former is. One reason for the deviations stems from low‐frequency vibrations which also contribute to the dynamic structure factor and which are small in fragile but large in strong liquids. A change of dynamics at T>Tg is also indicated in simple liquids by the emergence of a slow secondary relaxation process and by the break‐down of rotational‐translational coupling. Furthermore, a viscosity analysis is performed by introducing a crossover temperature Tx which marks the boundary between two dynamical regimes. For all glass formers a master curve is obtained at T<Tx. Tx is found to be close to Tc. Applying this scaling procedure to aluminosilicate melts, systematic trends as a function of the composition are revealed.
Correlation Between Surface Non‐Radiative Recombination and Current Oscillation at p‐Si(100) During Electropolishing in Fluoride Solution
Authors: Rappich J. , Yu. Timoshenko V. , Dittrich Th.
Published: July 2012

The electropolishing of p‐Si(100) in aqueous NH4F solution is investigated in‐situ by photoluminescence (PL) with short N2‐laser pulses. The PL signal increases with potential and reaches a maximum when current oscillations occur. The PL signal oscillates with the same period but anticorrelated to the current. The thin anodic oxides are removed at a low cathodic potential. The respective peak of the current transient is used to monitor the relative changes of the anodic oxides. The results are discussed from the point of view of non‐radiative defect generation during electropolishing, which is controlled by the potential and the rate of oxidation.
Static light scattering and small angle neutron scattering experiments with a nonionic surfactant/deuterium oxide system approaching the liquid/liquid coexistence curve: Study of the system C12E5/D2O
Authors: Lesemann M. , Martin A. , Belkoura L. , Woermann D. , Hoinkis E.
Published: July 2012

Static light scattering experiments with C12E5/D2O mixtures are carried out in the “large aggregate region” of the phase diagram of the system adjacent to the lower part of the binodal curve. They demonstrate the existence of concentration fluctuations with long range correlations. For a mixture of critical composition the correlation length § of the concentration fluctuations diverges approaching the critical temperatures Tc. The critical amplitude §0 has a value of §0 = 1.8 nm which is large compared to that found with nonaggregating binary liquid mixtures with a miscibility gap. The experimentally determined values of the critical exponents v and y are consistent with the theoretical expected universal values. For mixtures of noncritical composition § increases approaching the binodal curve and has a finite comparatively large value at the temperature of phase separation Tp. Small angle neutron scattering experiments with a C12E5/D2O mixture of critical composition show that the angular dependence of the scattered intensity becomes only approximately temperature independent approaching Tc (i.e. large values of the scaling variable x = q § (q, absolute value of the scattering vector). This is contrary to expectation. On the basis of the expression approximating the universal correlation scaling function for values of x<20 it is expected that the temperature dependence should vanish. From this findings taking into account also results of dynamic light scattering obtained with the same system (A. Martín et al., J. Phys. Chem. 100, 13762 (1996)) it is hypothesized that in the “large aggregate” region of the phase diagram adjacent to the binodal curve concentration fluctuations with long range correlations and their dynamics contribute to the changes of the size and shape of the micellar structures described in the literature.
Structural and electrochemical investigations of self‐assembled monolayers of azobenzenealkanethiol and ferrocenealkanethiol containing amido linkages
Authors: Yu Hua‐Zhong , Wang Yong‐Qiang , Cai Sheng‐Min , Liu Zhong‐Fan
Published: July 2012

Novel amido linkage containing molecules, HS‐CH2CH2NHC(O)‐Ar‐N = N‐Ar (AzoC2) and HS‐CH2CH2NHC(O)‐(η5‐C5H4)Fe(η5‐C5H5)(FcC2), for self‐assembly were synthesized. They spontaneously adsorb onto gold surface and form stable monolayers. These monolayers were thoroughly characterized by using contact angle measurements, grazing‐angle incidence infrared spectroscopy (GA‐FTIR) and cyclic voltammetry (CV). The structure and properties of the monolayers were found to be highly dependent on the functional moieties, ferrocene or azobenzene in their respective SAMs. The AzoC2 monolayer is more closely packed and highly oriented than FcC2 monolayer due to the interchain hydrogen bonding as evidenced by GA‐FTIR data. The FcC2 SAM is relatively loose with a low surface concentration. On the other hand, the electron‐transfer rate constant of AzoC2 SAM is much smaller than that of FcC2 system, although the redox centers are located at the same distance from the electrode surface. In this sense, the spatial inhibition for the proton transportation and structural conformational change in the redox process of azobenzene should be considered as the dominant reason for the low electron transfer rate constant.
Isomerization and dissociation in competition — The two‐component dissociation dynamics of energy‐selected C3H6O2+ isomers
Authors: Baer Tomas , Mazyar Oleg A. , Keister Jeffrey W. , Mayer Paul M.
Published: July 2012

The dissociation dynamics of three C3H6O2+ isomers (methyl acetate, acetol, and ethyl formate) are compared. Photoelectron photoion coincidence (PEPICO) mass spectrometry is used to energy select these ions above their dissociation limits. The dissociation rates are derived from the ion time of flight distributions. All three ions dissociate via two‐component decay rates which provides proof that these ions dissociate by competitive isomerization and dissociation steps. In each case a number of lower energy isomers are involved in the dissociation mechanism. However, it is interesting that these three ions do not share a common set of lower energy isomers. The conditions necessary for the observation of two‐component decay are described and the shapes of the resulting ion TOF distributions are illustrated.
Fluorescence lifetimes of jet‐cooled trans‐stilbene and its (1:1)‐van der Waals complexes with n‐hexane: Cluster effects in photoisomerisation
Authors: Lienau Christoph , Schroeder Jörg , Troe Jürgen , Wack Karsten
Published: July 2012

The excess energy dependence of the fluorescence decay of jet‐cooled trans‐stilbene in the vicinity of the photoisomerisation threshold is compared with k (E,J) as calculated from an optimized RRKM model. Van der Waals 1:1‐complexes between trans‐stilbene and n‐hexane are generated in a supersonic jet and identified by rotational coherence spectroscopy. A comparison of the fluorescence lifetimes of isolated trans‐stilbene and the 1:1‐complex in the excess energy range 0 < Eex > 2500 cm−1 provides evidence for a competition between the isomerisation of stilbene in the bound complex and fragmentation of the complex accompanied by internal energy loss in trans‐stilbene. The threshold energy for isomerisation in the 1:1‐complex is found to be approximately 300 cm−1 lower than for the isolated stilbene molecule.
Raman scattering from optically levitated microdroplets: Influence of input resonances on output resonances
Authors: Popp J. , Hartmann I. , Lankers M. , Trunk M. , Kiefer W.
Published: July 2012

In this paper we consider in detail the influence of input resonances (incident electromagnetic field is in resonance with the cavity) on the output resonances in Raman spectra (scattered Raman field is in resonance with the cavity) of optically levitated microdroplets. Dependent on the kind of input resonance the output resonances show spectral shifts. We explain that these shifts are the result of a temperature increase, due to an input resonance and weak absorbance of the microparticle. The main intention of this paper is to describe the dependence of these temperature increases on the kind of input resonance.
Salt effects on the proton transfer equilibria in the 3,5‐dinitro‐2‐hydroxybenzoic acid/ammonia system: A T‐jump study
Authors: Sánchez Antonio , Pérez Francisco , Galán Manuel
Published: July 2012

A thermodynamic study of the proton transfer equilibria involved in the system 3,5‐dinitro‐2‐hydroxybenzoic acid/ammonia has been undertaken in LiClO4 and NaClO4 aqueous solutions at different ionic strengths. The enthalpy for the different equilibria involved was measured by T‐jump techniques, while the free energies were determined spectrophotometrically.

The different thermodynamic magnitudes, ΔG, ΔH and TΔS, are functions of the nature and concentration of the salt. However, the MSA provides a reasonable explanation for the experimental trends in most of the cases, although in this model only one parameter, the radii of the ions, is used to reproduce the mean ionic activity coefficients of electrolyte solutions at high ionic strengths.

The extrapolated values at infinite dilution were also compared with the MSA prediction, and a good agreement was found.
Transferring freely suspended liquid‐crystal films on top of one another: A new method for the study of liquid‐crystal interfaces
Authors: Lucht R. , Bahr C. H.
Published: July 2012

We report a new experiment which consists of the transfer of a freely suspended liquid‐crystal film on the top of a second freely suspended liquid‐crystal film. Thereby a well defined interface between two liquid‐crystal materials and phases is produced.
Adsorption from binary solution in slit shaped pores
Authors: Borówko M. , Borówko P. , Rz̀ysko W.
Published: July 2012

A theoretical model for adsorption of a binary solution in a slit shaped pore is proposed. The classic lattice model of the solution is used. Adsorption systems exhibiting complete mixing are considered. The theoretical results are compared with Monte Carlo simulations in the grand canonical ensemble. An influence of pore size and non‐ideality of the liquid mixture on adsorption and selectivity is analysed.
Vapor‐Liquid equilibria of binary mixtures of n‐heptane with 1,1‐dimethylpropyl methyl ether and 1,1‐dimethylethyl methyl ether
Authors: Mößner Frank , Coto Baudilio , Pando Concepción , Renuncio Juan A.R.
Published: July 2012

Vapor‐liquid equilibrium data are reported for the binary mixtures formed by n‐heptane and the branched ethers 1,1‐dimethylpropyl methyl ether (tert‐amyl methyl ether or TAME) and 1,1‐dimethylethyl methyl ether (tert‐butyl methyl ether or MTBE). A Gibbs‐Van Ness type apparatus was used to obtain total vapor pressure measurements for n‐heptane‐MTBE and n‐heptane‐TAME mixtures at 298.15 and 308.15 K. The systems show very small positive deviations from Raoult's law with a nearly ideal behavior. Results are analyzed in terms of the Peng‐Robinson equation of state and the Wong‐Sandler mixing rule, the Lattice‐Fluid (LF) model, the UNIQUAC model, and several versions of the UNIFAC model.
Influence of the zeolite matrix on the optical properties and the stability of hosted PbS nano‐particles
Authors: Wark M. , Jaeger N. I. , Lutz W. , Tkachenko O. P.
Published: July 2012

The formation of PbS nano‐particles with narrow size‐distribution in zeolite X is reported. By control of the degree of ion exchange the mean diameters of the particles can be varied between 3 and 8 nm. Particles exceeding the dimension of the zeolitic supercages are hosted in intra‐zeolitic mesopores which are formed in dependence on the growth of the particles.

It is demonstrated that for zeolite‐hosted PdS nano‐particles the width of the optical band gap depends on size‐quantiation effects and on interactions between the particles and the host. As a consequence of its anionic character the zeolite framework generates extra charges (defect electrons) in the particles leading to an optical Burstein shift. From XPS it can be concluded that the polarisation of the Pb‐S bonds is the more pronounced the smaller the particles are. This results also in a decrease of their thermal stability.
Formation of amalgam particles in bimetallic silver and mercury colloids
Authors: Su Dangsheng , Katsikas Lynne , Giersig Michael
Published: July 2012

We report results gained in the transmission electron microscopy studying of silver and mercury colloids in an attempt to find the alloying behaviours of the two metals in the solution. Amalgam particles are formed, but aggregate and recrystallize to participates. While a large amount of mercury ions are reduced the small silver particles in the solution “disappear”. Then only relative large amalgam particles exist which sediment after some hours.
Synthesis and structural characterisation of Si and SiOx particles of nanometer sizes
Authors: Hofmeister H. , Ködderitzsch P. , Gösele U.
Published: July 2012

The possibilities of various gas phase processes for fabrication of nanosized Si and SiOx particles have been explored in a comparative Study. Conventional and high resolution electron microscopy was used to investigate in detail agglomeration, size, shape, crystallinity, surface roughness and internal structure of the particles, respectively. Accretions of nearly spherical crystalline Si particles of 2‐8 nm size mostly embedded in amorphous matrix were prepared by means of a gas evaporation cluster source. Their structural characteristics depend on the aggregation conditions applied. Inert gas are evaporation of silicon yielded single crystalline, spherical Si particles 4‐16 nm in size being completely free of defects. These particles, agglomerated into chains and tangles, are covered entirely by a thin amorphous oxide layer. Thermal evaporation of solid SiO in an inert gas atmosphere produced highly agglomerated, nearly spherical amorphous SiOx, particles 8‐24 nm in size with a considerable surface roughness. Upon annealing at 900°C the formation of 3‐6 nm sized Si crystallites in the interiro of these particles were observed.
Switching of optical properties in zeolitic nanocomposites
Authors: Marlow Frank , Hoffmann Katrin
Published: July 2012

The guest molecule azobenzene is aligned nearly perfectly by the channels of the molecular sieve AlPO4‐5. After irradiation with light of the wavelength 360 nm the configuration and the orientation of the molecules are changed. This results in changes of the refractive index. It turns out that this reaction is reversible (back reaction by irradiation with 436 nm) and that the change of the birefringence can be very large (δn' = 0,033). It is demonstrated that a crystal of a thickness of 13 μm is sufficient to be switched between a λ‐plate and a λ/2‐plate. This is an example of an opto‐optical microswitch.