bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of Catalyst Fragmentation in Gas‐Phase Olefin Polymerisation: A Novel Short Stop Reactor
Authors: Silva Fabricio M. , Broyer Jean P. , Novat Christian , Lima Enrique L. , Pinto José C. , McKenna Timothy F. 
Published: November 2005

AbstractSummary: A short stop reactor (SSR) was developed to study nascent particle morphology and reaction kinetics in the gas‐phase polymerisation of olefins on supported catalysts. It is shown that the SSR provides a useful means to look into important phenomena such as catalyst fragmentation and catalyst site activation and deactivation that take place during the very early stages of the heterogeneous polymerisation of olefins. New experimental results obtained from gas‐phase polymerisation of ethylene show that, depending on the type of catalyst system and on the reaction conditions, different kinds of morphologies can be obtained for the nascent polymer (e.g., cracks and folded chain). Experimental data also indicate that the growth of the polymer chains occur at a non‐steady state during the very early stages of the polymerisation.SEM image showing the morphology of a polymer/catalyst particle after 2 seconds of polymerisation at 8 bars of ethylene on an MgCl2‐supported Ziegler‐Natta catalyst.magnified imageSEM image showing the morphology of a polymer/catalyst particle after 2 seconds of polymerisation at 8 bars of ethylene on an MgCl2‐supported Ziegler‐Natta catalyst.
Electronic Properties and Field‐Effect Transistors of Thiophene‐Based Donor–Acceptor Conjugated Copolymers
Authors: Champion Richard D. , Cheng Kai‐Fang , Pai Chia‐Ling , Chen Wen‐Chang , Jenekhe Samson A. 
Published: November 2005

AbstractSummary: The thiophene‐quinoxaline donor–acceptor conjugated copolymer poly[(thiophene‐2,5‐diyl‐alt‐(2,3‐diheptylquinoxaline‐5,8‐diyl)] (PTHQx) was explored as a semiconductor in thin‐film organic field‐effect transistors (OFETs). A hole mobility of 3.6 × 10−3 cm2 · V−1 · s−1 and an on/off current ratio of 6 × 105 were observed in p‐channel OFETs made from spin‐coated PTHQx thin films. The electronic structures of PTHQx and a related thiophene‐thienopyrazine donor–acceptor copolymer were calculated by density functional theory. Atomic force microscopy of PTHQx thin films showed a polycrystalline grain morphology that varied with the substrate.Output (left) and transfer (right) characteristics of a PTHQx (structure shown) organic field‐effect transistor.magnified imageOutput (left) and transfer (right) characteristics of a PTHQx (structure shown) organic field‐effect transistor.
Inkjet Printing of Functional Polymers and Materials: 2nd International Workshop in Eindhoven
Authors: Tekin Emine , Schubert Ulrich S. 
Published: November 2005

AbstractThis section contains reports on topical conferences. Reports are usually written at the request of the editorial office, but unsolicited contributions are also welcome. Suggestions should be sent to the editorial office of the Macromolecular journals, preferably by E‐mail to macromol@wiley‐vch.de.
The role of mass spectrometry in plant systems biology
Authors: Glinski Mirko , Weckwerth Wolfram 
Published: November 2005

AbstractLarge‐scale analyses of proteins and metabolites are intimately bound to advancements in MS technologies. The aim of these non‐targeted “omic” technologies is to extend our understanding beyond the analysis of only parts of the system. Here, metabolomics and proteomics emerged in parallel with the development of novel mass analyzers and hyphenated techniques such as gas chromatography coupled to time‐of‐flight mass spectrometry (GC‐TOF‐MS) and multidimensional liquid chromatography coupled to mass spectrometry (LC‐MS). The analysis of (i) proteins (ii) phosphoproteins, and (iii) metabolites is discussed in the context of plant physiology and environment and with a focus on novel method developments. Recently published studies measuring dynamic (quantitative) behavior at these levels are summarized; for these works, the completely sequenced plantsArabidopsis thalianaandOryza sativa(rice) have been the primary models of choice. Particular emphasis is given to key physiological processes such as metabolism, development, stress, and defense. Moreover, attempts to combine spatial, tissue‐specific resolution with systematic profiling are described. Finally, we summarize the initial steps to characterize the molecular plant phenotype as a corollary of environment and genotype. © 2005 Wiley Periodicals, Inc. Mass Spec Rev 25:173–214, 2006
Phosphorus Dendrimers: Nano‐objects for Nanosciences
Authors: Majoral Jean‐Pierre , Turrin Cédric‐Olivier , Laurent Régis , Caminade Anne‐Marie 
Published: November 2005

AbstractSummary: The influence of the size (the generation) of phosphorus dendrimers on their properties is discussed in three main fields of applications: catalysis, new materials, and biology. Typical examples are given to illustrate these three fields: Knoevenagel condensation for catalysis, elaboration of highly sensitive DNA chips for materials, transfection experiments, and anti‐prion activity for biology.
New Perspectives in Living/Controlled Anionic Polymerization
Authors: Deffieux Alain , Carlotti Stéphane , Desbois Philippe 
Published: November 2005

AbstractSummary: Control of the reactivity and selectivity of active species remains a major challenge in the course of living/controlled polymerizations of vinyl and heterocyclic monomers. We have found that alkyl metal derivatives such as dialkylmagnesium or trialkylaluminum derivatives or the corresponding alkoxyakyl metal derivatives, when added to conventional anionic polymerization systems, are very effective mediators for the controlled anionic polymerization of both styrenic and oxirane monomers. When used as additives to alkali metal alkyl initiators (alkyl lithium, alkyl sodium) for the styrene anionic polymerizations, they strongly retard the reactivity of the propagating species and allow controlling the polymerization in very unusual conditions (bulk, very high temperature). On the contrary, when used in combination to the same alkali metal based initiators for the anionic polymerization of ethylene oxide or propylene oxide, these additives can drastically enhance the reactivity and the selectivity of the propagating species allowing a fast living‐like polymerization to proceed already at low temperature in hydrocarbon media.
Surface Assisted Nucleation and Growth of Polymer Latexes on Organically‐Modified Inorganic Particles
Authors: Bourgeat‐Lami Elodie , Herrera Norma Negrete , Putaux Jean‐Luc , Reculusa Stéphane , Perro Adeline , Ravaine Serge , Mingotaud Christophe , Duguet Etienne 
Published: November 2005

AbstractSummary: Polymer latex particles were synthesized in the presence of inorganic particles, which had been organically‐modified to promote favorable interactions with growing macromolecules. The organic modification was performed using three different routes: (1) surface covalent grafting of vinyl trialkoxysilanes, (2) surface adsorption of polyethylene glycol‐based macromonomers, and (3) bulk modification through ion exchange with cationic monomers or cationic initiators. Two types of mineral particles were studied: commercial and self‐prepared silica particles (with diameters from 80 nm to 1 µm), and commercial laponite clay particles with a cation exchange capacity of 0.75 meq · g−1. Emulsion polymerization was performed in the presence of styrene or butyl acrylate monomers. The morphologies of the nanocomposite particles were observed by (cryogenic) transmission electron microscopy and correlated to the organic modification procedure.
Reactive Polymer Based Colloids for Biomedical Applications
Authors: Elaissari Abdelhamid 
Published: November 2005

AbstractSummary: This short review aimed to give to the reader brief applications of polymer colloids in biomedical area and principally in medical diagnostics. Colloidal polymer particles are mainly used as solid supports, as label for biomolecules reactions detection, and as a carrier. The elaboration of appropriate colloids is reached via numerous processes such as polymerization in dispersed media (dispersion, emulsion, precipitation, miniemulsion polymerizations) or as physico‐chemical methodologies (i.e., self‐assembly). After a short introduction, some particles elaborations are presented and their applications are briefly described and illustrated.
Morphology and Structure of Crystalline Polysaccharides: Some Recent Studies
Authors: Putaux Jean‐Luc 
Published: November 2005

AbstractSummary: In this paper, we review recent studies on the morphology and molecular structure of some polysaccharide crystals from amylose, cellulose, and mannan. The data were recorded using combinations of imaging, diffraction, and spectroscopic techniques: scanning and transmission electron microscopy, electron, neutron, and X‐ray diffraction, as well as 13C solid‐state NMR spectroscopy. Differences were generally found between native crystals, whose features result from in vivo biogenesis and the recrystallized products prepared in vitro.
Effect of Initiator on the Incorporation of Graphite into Polymer Matrix During Suspension Polymerization
Authors: Lopes Cristiane N. , Moreira Regina F. P. M. , Machado Ricardo A. F. , Araújo Pedro H. H. 
Published: November 2005

AbstractSummary: The incorporation of graphite into polystyrene (PS) particles produced by suspension polymerization was studied using a monofunctional and a bifunctional initiator, benzoyl peroxide (BPO) and 2,5‐dimethyl‐2,5‐bis(2‐ethyl hexanoyl peroxide) hexane (L256), respectively. The results showed that the polymerization rate was affected by graphite concentration when BPO was used as the initiator while no such effect was observed for L256. Results also showed that the incorporation of graphite in the PS particles was higher when using BPO than when using L256. Molecular weight distribution showed that during the reaction with BPO and graphite oligomers were formed indicating that the free radicals generated by the decomposition of BPO presented a very high reactivity with the functional groups present at the graphite surface while no significant effect was observed for the reaction with L256.
Deriving Molecular Parameters of Interfaces Between Chemically Identical Polymers from Macroscopically Observed Phenomena
Authors: Reiter Günter 
Published: November 2005

AbstractSummary: By utilizing model systems, macroscopically observable phenomena like friction or dewetting allow to identify and to quantify molecular interfacial parameters like molecular interpenetration depth, interfacial tension, or slippage length between grafted and free chemically identical polymers. We present experimental results, which permit to extract these parameters from simple contact angle measurements or by following the dewetting process in real time with a simple optical microscope. We also show how these model experiments can provide valuable insight and fundamental understanding of processes like polymeric friction and adhesion.
Polycaprolactone‐b‐Poly(ethylene oxide) Biocompatible Micelles as Drug Delivery Nanocarriers: Dynamic Light Scattering and Fluorescence Experiments
Authors: Giacomelli Cristiano , Lafitte Gabriel , Borsali Redouane 
Published: November 2005

AbstractSummary:Dynamic light scattering (DLS) and fluorescence experiments were carried out to study PCL44‐b‐PEO114biocompatible micelles used as nanocarriers in drug delivery. Micelles prepared by a simple procedure (THF removal under nitrogen flow) exhibited a narrow size distribution with an average diameter of 100 nm. For micelles containing a hydrophobic model compound (pyrene) within the PCL core, a smaller average micellar size of 80 nm was observed, with a simultaneous broadening in the size distribution profile. In parallel to DLS results, fluorescence experiments showed evidence of pyrene encapsulation, and that the onset of the micellization process occurs at approximately 10/90 (v/v) THF/water mixtures in the case of PCL44‐b‐PEO114polymer.
Anthraquinone and Azo Dyes in Dyeing Processes of PET Films and PET Knitted Fabrics Using Supercritical CO2 Medium
Authors: Santos Washington L. F. , Moura Ana P. , Povh Nanci P. , Muniz Edvani C. , Rubira Adley F. 
Published: November 2005

AbstractSummary: Dyeing processes using supercritical fluid present advantages over the conventional dyeing process using aqueous medium. Previous works from our group on polymeric fibers such as N,N‐dimethylacrylamide (DMAAm) modified poly(ethylene terephthalate), PET, showed higher sorption of disperse dyes in supercritical medium. Furthermore, recent studies showed that the association of UV radiation and DMAAm treatment leads to a better incorporation of dyes in modified PET soaked in aqueous medium. In this work, modified and non‐modified PET knitted fabrics (KF) were dyed in supercritical CO2 medium. Azo and anthraquinone dyes were used in order to compare the extent of incorporated dye in PET films and PET KF in supercritical CO2. The dyeing process variables were studied by factorial design and by a response surface methodology (RSM) technique. The anthraquinone dye presented a better incorporation in PET than the azo dye. The UV light exposure and the dyeing times inputs showed positive main effects in the incorporation of dyes in PET films and PET KF. From the RSM data, DMAAm and UV light modified PET KF presented 7.43 mg of incorporated azo dye by g of PET if the optimized dyeing conditions, time: 135 min and pressure: 212 bar would be used. In the respective optimized dyeing conditions for the anthraquinone dye, time 150 min and pressure 229 bar, the incorporated dye would be 22.9 mg of dye by g of PET.
Large Plastic Deformation of Isotactic Poly(propylene) (iPP) Evaluated by WAXD Techniques
Authors: Samios Dimitrios , Tokumoto Shinichi , Denardin Elton L. G. 
Published: November 2005

AbstractSummary: Commercial isotactic poly(propylene) (iPP), obtained in bars, was annealed and submitted to different levels of plastic deformation by uniaxial plane compression using a special device which permits well controlled temperature and strain rate. The evolution of the microstructure was followed at different degrees of deformation by wide angle x‐ray diffraction (WAXD) techniques. The spherulite fragmentation process, lamellar orientation and destruction of the crystallites is argued, according to collected analytical data in the flow direction (FD), the loading direction (LD) and the lateral or constrain direction (CD). The evaluation of the WAXD patterns in terms of diffraction line position, intensity and width, permits to affirm that, while the large plastic deformation occurs, the crystalline net suffers anisotropic deformation, the crystallites become preferentially oriented along the flow direction and the crystalline phase diminish in amount indicating lesser and smaller crystallites. The gradual lamellae fragmentation occurs, starting with apparent crystalline size of approximately 30 nm for the non‐deformed material and gradually decreasing to approximately 15 nm for the 70% deformed one.
A New ESIPT Fluorescent Dye‐Doped Silica Aerogel
Authors: Rodembusch Fabiano Severo , Campo Leandra Franciscato , Rigacci Arnaud , Stefani Valter 
Published: November 2005

AbstractSummary: A silyl‐functionalized benzazole dye, fluorescent by excited state intramolecular proton transfer (ESIPT) mechanism, was synthesized by reacting 2‐(2′‐hydroxyphenyl)benzoxazole with 3‐(triethoxysilyl)propyl isocyanate. The fluorescent silica gel was prepared by the addition of a solution of 2‐propanol and the fluorescent dye after the gelation time. The monolithic aerogel was obtained via supercritical CO2 drying of the fluorescent gel. The resulting aerogel is transparent in the visible light and fluorescent in the blue‐green region under UV radiation.
Synthesis and Characterization of Chiral [3,22]‐Ionenes
Authors: Bazito Reinaldo C. , Cássio Fernando L. , Quina Frank H. 
Published: November 2005

AbstractSummary: Two [3,22]‐ionenes with pendent chiral groups, glucopyranosyl‐[3,22]‐ionene and β‐cyclodextrin‐[3,22]‐ionene, were synthesized by the reaction between the tosyl derivatives of the carbohydrate (methyl alpha‐glucopyranoside or beta‐cyclodextrin) and the tertiary [3,22]‐polyamine obtained by selective demethylation of [3,22]‐ionene. The derivatives were characterized by 1H NMR spectroscopy, presenting degrees of substitution of 30 and 45% for the glucosyl and cyclodextrin derivatives, respectively. It was shown by using pyrene as the fluorescent probe, that both polymers form hydrophobic domains, characteristic of micelle‐mimetic polysoaps in aqueous solution.
Competitive Process of Binding Between the Anionic Surfactants Sodium Dodecyl Sulfate and Sodium Cholate in Bovine Serum Albumin
Authors: Schweitzer Bianca , Felippe Arlindo C. , Dal Bó Alexandre , Minatti Edson , Zanette Dino 
Published: November 2005

AbstractSummary: In this study sodium cholate (NaC) was used as a representative bile salt for the competitive binding between NaC and sodium dodecyl sulfate (SDS) in bovine serum albumin (BSA), in 0.02 M tris‐HCl buffer solution at pH 7.50 and 25 °C. The NaC and SDS associations with BSA were monitored at low surfactant concentrations where only this specific binding process can develop. The applied method to monitor the binding was based on the analysis of the effect of SDS and NaC concentrations and their mixtures upon the fluorescence intensity of the BSA tryptophan residues. This consists of the measurement of the surfactant monomer partitioning between the dispersion medium and the microaggregates on the protein molecule where the binding is indicated by the quenching of the fluorescence chromophores. Experimentally, varying the protein concentration, the surfactant concentration needed to reach a given Io/I ratio (Io and I are the intensities with and without protein, respectively) was measured. The analyses, based on the average number of surfactant molecules bound on the protein, indicated that the SDS is a more efficient quencher than the bile salt. The need for 4–6 NaC bound molecules to give the same protein quenching efficiency by a single molecule of SDS was estimated. We concluded that the differences in the competitive binding on the protein are exclusively related to the quenching efficiency in the formation of the nonfluorescent fluorophore‐quencher complex via a physical contact and static quenching process.
Carboxyl Terminated Polymer Chain Extension Using a Bisoxazoline Coupling Agent: Monte Carlo Simulation
Authors: Yan Li‐Tang , Xu Jun , Qian Zhen‐Yu , Guo Bao‐Hua , Xie Xu‐Ming 
Published: November 2005

AbstractSummary: The kinetics of the chain extension reaction of a carboxyl‐terminated polymer using a bisoxazoline coupling agent was simulated by the Monte Carlo method based on the master equation. The effects of temperature and stepwise addition of the chain extender was examined. A comparison between simulated results and those calculated by an amended kinetic model was made. The results show that the highest coupling efficiency and the highest $\overline M _{\rm n}$ can be obtained when the initial concentrations of carboxyl and oxazoline groups are equal, which is in good agreement with the experiments. It is found that a higher reaction temperature could lead to a bigger coupling efficiency, a higher $\overline M _{\rm n}$ and narrower MWDs. The stepwise addition of the chain extender can only postpone the chain extension reaction, but cannot affect the final coupling efficiency and the MWDs when the concentration of the oxazoline group is lower than that of the carboxyl group. However, stepwise addition of the chain extender favors bigger coupling efficiency and narrower MWDs when the concentration of the oxazoline group exceeds that of the carboxyl group.The relationship among three group of polymers, r and ratios of k2 to k1. The dots are the data simulated by MC and solid lines are relative data calculated by the kinetic model.magnified imageThe relationship among three group of polymers, r and ratios of k2 to k1. The dots are the data simulated by MC and solid lines are relative data calculated by the kinetic model.
A new fuzzy multicriteria evaluation method for group site selection in GIS
Authors: Bailey David , Goonetilleke Ashantha , Campbell Duncan 
Published: November 2005

AbstractMultiple criteria group site selection problems involve a group of individuals evaluating a set of alternative sites on the basis of multiple criteria. This paper presents an application of a new fuzzy algorithm for finding and exploring potential solutions to these problems in a raster Geographical Information System (GIS) environment. Linguistic assessments from decision‐makers are represented as triangular fuzzy numbers (TFN's), which are adjusted for uncertainty in the source data and their relationship to suitability by using an approach based on type‐2 fuzzy sets. The first aggregation of inputs is a compensatory one based on fuzzy multiattribute decision‐making (MADM) theory. An adjusted aggregation then factors in conflicts, risks and uncertainties to enable a variety of compensatory and non‐compensatory outcomes to be generated based on decision‐maker preferences. The algorithm was implemented in ArcView GIS as part of an ongoing collaborative project with Brisbane Airport. This paper outlines the fuzzy algorithm and its use in site selection for a recycling facility on the Brisbane Airport site. Copyright © 2005 John Wiley & Sons, Ltd.
Fuzzy MCDM based on the concept of α‐cut
Authors: Liang Gin‐Shuh , Ding Ji‐Feng 
Published: November 2005

AbstractIn a fuzzy multiple criteria decision‐making (MCDM) problem, with a hierarchical structure of more than two levels and involving multiple decision‐makers (DMs), to find the exact membership functions of the final aggregation ratings of all feasible alternatives is almost impossible. Thus, ranking methods based on exact membership functions cannot be utilized to rank the feasible alternatives and complete the optimal selection. To resolve the above‐mentioned complexity and to incorporate assessments of all DMs' viewpoints, in this paper a fuzzy MCDM method with multiple DMs, based on the concepts of fuzzy set theory and α‐cut, is developed. This method incorporates a number of perspectives on how to approach the fuzzy MCDM problem with multiple DMs, as follows: (1) combining quantitative and qualitative criteria as well as negative and positive ones; (2) using the generalized means to develop the aggregation method of multiple DMs' opinions; (3) incorporating the risk attitude index β to convey the total risk attitude of all DMs by using the estimation data obtained at the data input stage; (4) employing the algebraic operations of fuzzy numbers based on the concept of α‐cut to calculate the final aggregation ratings and develop a matching ranking method for proposed fuzzy MCDM method with multiple DMs. Furthermore, we use this method to survey the site selection for free port zone (FPZ) in Taiwan as an empirical study to demonstrate the proposed fuzzy MCDM algorithm. The result of this empirical investigation shows that the port of Kaohsiung, the largest international port of Taiwan as well as the sixth container port in the world in 2004, is optimal for the Taiwan government in enacting the plan of FPZ. Copyright © 2005 John Wiley & Sons, Ltd.