bluuebunny/crossref_metadata_2025_split huggingface dataset:
Side‐chain polypseudorotaxanes by threading cucurbit[7]uril onto poly‐N‐n‐butyl‐N′‐(4‐vinylbenzyl)‐4,4′‐bipyridinium bromide chloride: Synthesis, characterization, and properties
Authors: Yang Hui , Tan Yebang , Hao Jingcheng , Yang Huabiao , Liu Fawen 
Published: April 2010

AbstractA novel side‐chain polypseudorotaxanes P4VBVBu/CB[7] was synthesized from poly‐N‐n‐butyl‐N′‐(4‐vinylbenzyl)‐4,4′‐bipyridinium bromide chloride (P4VBVBu) and cucurbit [7]uril (CB[7]) in water by simple stirring at room temperature. CB[7] beads are localized on viologen units in side chains of polypseudorotaxanes as shown by 1H NMR, IR, XRD, and UV–vis studies, and it is considered that the hydrophobic and charge‐dipole interactions are the driving forces. TGA data show that thermal stability of the polypseudorotaxanes increases with the adding of CB[7] threaded. DLS data show that P4VBVBu and CB[7] could form polypseudorotaxanes, and the average hydrodynamic radius of the polypseudorotaxanes increases with increasing the concentration of CB[7]. The typical cyclic voltammograms indicate that the oxidation reduction characteristic of P4VBVBu is remarkably affected by the addition of CB[7] because of the formation of polypseudorotaxanes and the shielding effects of CB[7] threaded on the viologen units of polypseudorotaxanes. With the increase of the concentration of KBr or K2SO4, the formation of the polypseudorotaxanes was inhibited due to the shielding effects of both Br− or SO to viologen ion and K+ to CB[7] by UV–vis. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2135–2142, 2010
Dual‐responsive supramolecular inclusion complexes of block copolymer poly(ethylene glycol)‐block‐poly[(2‐dimethylamino)ethyl methacrylate] with α‐cyclodextrin
Authors: Sui Kunyan , Shan Xin , Gao Song , Xia Yanzhi , Zheng Qiang , Xie Dan 
Published: April 2010

AbstractA new class of temperature and pH dual‐responsive and injectable supramolecular hydrogel was developed, which was formed from block copolymer poly(ethylene glycol)‐block‐poly[(2‐dimethylamino)ethyl methacrylate] (PEG‐b‐PDMAEMA) and α‐cyclodextrin (α‐CD) inclusion complexes (ICs). The PEG‐b‐PDMAEMA diblock copolymers with different ratio of ethylene glycol (EG) to (2‐dimethylamino)ethyl methacrylate (DMAEMA) (102:46 and 102:96, respectively) were prepared by atom transfer radical polymerization (ATRP). 1H NMR measurement indicated that the ratio of EG unit to α‐CD in the resulted ICs was higher than 2:1. Thermal analysis showed that thermal stability of ICs was improved. The rheology studies showed that the hydrogels were temperature and pH sensitive. Moreover, the hydrogels were thixotropic and reversible. The self‐assembly morphologies of the ICs in different pH and ionic strength environment were studied by transmission electron microscopy. The formed biocompatible micelles have potential applications as biomedical and stimulus‐responsive material. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2143–2153, 2010
Synthesis and properties of cyclic diester based aliphatic copolyesters
Authors: Liu Yanchun , Turner S. Richard 
Published: April 2010

AbstractMelt polycondensation was used to prepare a systematic series of random and amorphous copolyesters using the following cycloaliphatic diesters: dimethyl‐1,4‐cyclohexane dicarboxylate (DMCD), dimethyl bicyclo[2.2.1]heptane‐1,4‐dicarboxylate (DMCD‐1), dimethyl bicyclo[2.2.2]octane‐1,4‐dicarboxylate (DMCD‐2), dimethyl bicyclo[3.2.2]nonane‐1,5‐dicarboxylate (DMCD‐3), 1,4‐dimethoxycarbonyl‐1,4‐dimethylcyclohexane (DMCD‐M) and the aliphatic diols: ethylene glycol (EG) and 1,4‐cyclohexane dimethanol (CHDM). The polymer compositions were determined by nuclear magnetic resonance (NMR) and the molecular weights were determined using size exclusion chromatography (SEC). The polyesters were characterized by dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The copolyester based on DMCD‐2 was observed to have a higher glass transition temperature (Tg up to 115 °C) than the other copolyesters of this study. For poly[x(DMCD‐2)y(DMCD) 30(EG)70(CHDM)], Tg increases linearly with increase of DMCD‐2 mole content. DMA showed that all of the cycloaliphatic copolyesters have secondary relaxations, resulting from the conformational transitions of the cyclohexylene rings. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2162–2169, 2010
Proton‐conducting electrolytes based on silylated and sulfonated polyetheretherketone: Synthesis and characterization
Authors: de Bonis Catia , D'Epifanio Alessandra , Di Vona Maria Luisa , Mecheri Barbara , Traversa Enrico , Trombetta Marcella , Licoccia Silvia 
Published: April 2010

AbstractA derivative of polyetheretherketone (PEEK) having sulfonic acid groups and silicon‐containing substituents covalently bound to the aromatic backbone has been prepared as proton‐exchange membrane material. The polymer 4 (PhSiSPEEK) has been synthesized via (i) sulfonation of PEEK up to 0.9 degree of sulfonation (DS, the number of sulfonic groups per repeat unit), (ii) conversion of sulfonated PEEK 1 (SPEEK09) into sulfonyl chlorinated derivative 2 (PEEKSO2Cl), (iii) lithiation of 2 and subsequent addition of PhSiCl3, followed by hydrolysis. The chemical structure of the synthesized polymers has been investigated by 1H NMR and 13C NMR and ATR/FTIR spectroscopy and their thermal stability has been evaluated by thermogravimetric analysis. The presence of inorganic moieties increases the thermal stability of 4 with respect to the sulfonated and not silylated product. Despite its very high DS, PhSiSPEEK is insoluble in water but does not possess the plastic properties needed to be used as an electrolyte membrane. Blend membranes made of SPEEK05 (DS = 0.5) and containing 10 and 25 wt % of 4 (DS = 0.9, degree of silylation DSi = 0.1) have been prepared and characterized by water uptake measurements and electrochemical impedance spectroscopy. The combination of the two functionalized polymers having different properties allows to obtain proton‐conducting electrolytes that are potential candidates for fuel cells applications. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2178–2186, 2010
Formation of conjugated polynaphthalene via Bergman cyclization
Authors: Miao Changcheng , Zhi Jian , Sun Shiyuan , Yang Xi , Hu Aiguo 
Published: April 2010

AbstractA series of enediyne containing chiral phthalimides were synthesized through Sonogashira coupling reactions. These enediynes were then subjected to thermal Bergman cyclization under vacuum. Polynaphthalenes with pendant chiral groups were obtained and characterized using GPC, IR spectroscopy, NMR spectroscopy, UV–Vis spectroscopy, and photoluminescence analysis. Under properly optimized conditions, the chirality of chiral directing group was maintained according to CD spectra of final products. After removal of chiral directing groups, weak CD signals representative of main chain chirality were visible. Further modification of the structure of the enediyne compounds will facilitate the synthesis of chiral polynaphthalene through this rather simple way. Extension of the Bergman cyclization to polymer chemistry is promising in the construction of novel polymers with rigid polyarene backbones. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2187–2193, 2010
Initiating electropolymerization on graphene sheets in graphite oxide structure
Authors: Eftekhari Ali , Yazdani Bahareh 
Published: April 2010

AbstractBecause of its special chemical composition, graphite oxide has peculiar influences on electrochemical processes. The existence of various functional groups significantly affects electropolymerization processes and the formation of conductive polymers. Electrochemical synthesis of polyaniline (as a prototype of conductive polymers) on a paste‐based substrate of graphite oxide was investigated. In this case, the electropolymerization is significantly different from conventional cases, and the polymer is generated just during the first potential cycle. This can be attributed to the fact that graphite oxide can assist the monomer oxidation. Alternatively, electropolymerization was successfully performed inside the graphite oxide layers via electrochemical treatment of aniline‐intercalated graphite oxide in the supporting electrolyte. Although these phenomena are related to the chemical composition of graphite oxide, the graphite prepared by the reduction of graphite oxide also displayed some advantages for the electropolymerization (over natural graphite). There is an emphasis on the morphological investigations throughout this study, because novel morphologies were observed in the system under investigation. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2204–2213, 2010
Kinetic analysis of nitroxide radical coupling reactions mediated by CuBr
Authors: Kulis Jakov , Bell Craig A. , Micallef Aaron S. , Monteiro Michael J. 
Published: April 2010

AbstractIn a previous paper, we described the room temperature rapid, selective, reversible, and near quantitative Cu‐activated nitroxide radical coupling (NRC) technique to prepare 3‐arm polystyrene stars. In this work, we evaluated the Cu‐activation mechanism, either conventional atom transfer or single electron transfer (SET), through kinetic simulations. Simulation data showed that one can describe the system by either activation mechanism. We also found through simulations that bimolecular radical termination, regardless of activation mechanism, was extremely low and could be considered negligible in an NRC reaction. Experiments were carried out to form 2‐ and 3‐arm PSTY stars using two ligands, PMDETA and Me6TREN, in a range of solvent conditions by varying the ratio of DMSO to toluene, and over a wide temperature range. The rate of 2‐ or 3‐arm star formation was governed by the choice of solvent and ligand. The combination of Me6TREN and toluene/DMSO showed a relatively temperature independent rate, and remarkably reached near quantitative yields for 2‐arm star formation after only 1 min at 25 °C. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2214–2223, 2010
New approaches to hyperbranched poly(4‐chloromethylstyrene) and introduction of various functional end groups by polymer‐analogous reactions
Authors: Georgi Ulrike , Erber Michael , Stadermann Jan , Abulikemu Mahebubaimu , Komber Hartmut , Lederer Albena , Voit Brigitte 
Published: April 2010

AbstractA facile way for the synthesis of hyperbranched poly(4‐chloromethylstyrene) [P(4‐CMS)] with adjustable molar mass by classic atom transfer radical polymerization (ATRP) and mechanistically similar procedures is presented. Subsequently, the chlorine functional groups have been modified to obtain polymers with different polarities. On the one hand, the polymer was end‐capped with unpolar groups (e.g., methyl, phenol ether) to obtain chemically inert substances. On the other hand, more complex functional groups have been introduced through azide groups by 1,3‐dipolar cycloaddition reaction (“click chemistry”). Furthermore, a method for the introduction of ester groups under mild conditions using cesium carboxylates is presented, which also allowed the preparation of so‐called hyperstars by attaching COOH functionalized polystyrene chains onto the P(4‐CMS) as core molecule. All these reactions were carried out in high or very high yields. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2224–2235, 2010
SET‐LRP of methyl methacrylate initiated with CCl4 in the presence and absence of air
Authors: Fleischmann Sven , Percec Virgil 
Published: April 2010

AbstractSingle electron transfer‐living radical polymerization (SET‐LRP) represents a robust and versatile method for the rapid synthesis of macromolecules with defined architecture. The synthesis of poly(methyl methacrylate) via SET‐LRP in dimethyl sulfoxide (DMSO) by using CCl4 as initiator is demonstrated in this work. Resorting to a rather simple Cu(0)/Me6‐TREN catalyst a method was established that allowed for the straightforward design of well‐defined poly(methyl methacrylate). The reactions were performed at various temperatures (25, 50, 60, and 80 °C) and complete monomer conversion could be achieved. The polymerizations obeyed first order kinetic, the molecular weights increased linearly with conversion and the polymers exhibited narrow molecular weight distributions all indicating the livingness of the process. By providing a small amount of hydrazine to the reaction mixture the polymerization could be conducted in presence of air omitting the need for any elaborated deoxygenation procedures. This methodology offers an elegant way to synthesize functionalized poly(methyl methacrylate) with perfect control over the polymerization process as well as molecular architecture. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2243–2250, 2010
Synthesis of well‐defined photoresist materials by SET‐LRP
Authors: Fleischmann Sven , Percec Virgil 
Published: April 2010

AbstractSingle electron transfer‐living radical polymerization (SET‐LRP) provides an excellent tool for the straightforward synthesis of well‐defined macromolecules. Heterogeneous Cu(0)‐ catalysis is employed to synthesize a novel photoresist material with high control over the molecular architecture. Poly(γ‐butyrolactone methacrylate)‐co‐(methyladamantly methacrylate) was synthesized. Kinetic experiments were conducted demonstrating that both monomers, γ‐butyrolactone methacrylate (GBLMA) and methyl adamantly methacrylate (MAMA), are successfully homopolymerized. In both cases polymerization kinetic is of first order and the molecular weights increase linearly with conversion. The choice of a proper solvent was decisive for the SET‐LRP process and organic solvent mixtures were found to be most suitable. Also, the kinetic of the copolymerization of GBLMA and MAMA was investigated. Following first order kinetics in overall monomer consumption and exhibiting a linear relationship between molecular weights and conversion a “living” process was established. This allowed for the straightforward synthesis of well‐defined photoresist polymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2251–2255, 2010
Analysis of ascorbic acid based black powder substitutes by high‐performance liquid chromatography/electrospray ionization quadrupole time‐of‐flight mass spectrometry
Authors: Bottegal Megan , Lang Lisa , Miller Mark , McCord Bruce 
Published: April 2010

AbstractBlack powder substitutes are an important sub‐group of explosive propellants in the United States because they are readily accessible, and can be used as fillers for improvised explosive devices. Many brands of black powder substitutes incorporate an ascorbic acid fuel source with potassium nitrate (KNO3) and/or potassium perchlorate (KClO4) oxidizer(s). A gradient high‐performance liquid chromatography/electrospray ionization quadrupole time‐of‐flight mass spectrometry (HPLC/ESI‐QToFMS) method has been developed for the analysis of both the organic and the inorganic constituents. The HPLC/ESI‐QToFMS method was utilized to examine aqueous extracts of intact samples and post‐burn residues from six different brands of ascorbic acid based powders. Aqueous extracts of the post‐blast residues from two brands of ascorbic acid based propellant were also analyzed. The results showed that both the ascorbic acid fuel and the inorganic oxidizer(s) KClO4 and/or KNO3 were successfully detected via the [M–H]− ion of ascorbic acid and the anions (ClO and NO) of the oxidizers. This method was proven to be a rapid and efficient procedure for the analysis of this class of explosives. The high mass resolution provided by the QToFMS instrument fulfills the degree of certainty required in a court of law. Published in 2010 by John Wiley & Sons, Ltd.
A consistency‐adjusted alpha‐adaptive strategy for sequential testing
Authors: Alosh Mohamed , Huque Mohammad F. 
Published: April 2010

AbstractIn a clinical trial with two clinically important endpoints, each of which can fully characterize a treatment benefit to support an efficacy claim by itself, a minimum degree of consistency in the findings is expected; otherwise interpretation of study findings can be problematic. Clinical trial literature contains examples where lack of consistency in the findings of clinically relevant endpoints led to difficulties in interpreting study results. The aim of this paper is to introduce this consistency concept at the study design stage and investigate the consequences of its implementation in the statistical analysis plan. The proposed methodology allows testing of hierarchically ordered endpoints to proceed as long as a pre‐specified consistency criterion is met. In addition, while an initial allocation of the alpha level is specified for the ordered endpoints at the design stage, the methodology allows the alpha level allocated to the second endpoint to be adaptive to the findings of the first endpoint. In addition, the methodology takes into account the correlation between the endpoints in calculating the significance level and the power of the test for the next endpoint. The proposed Consistency‐Adjusted Alpha‐Adaptive Strategy (CAAAS) is very general. Several of the well‐known multiplicity adjustment approaches arise as special cases of this strategy by appropriate selection of the consistency level and the form of alpha‐adaptation function. We discuss control of the Type I error rate as well as power of the proposed methodology and consider its application to clinical trial data. Published in 2010 by John Wiley & Sons, Ltd.
Voicing differences: Indigenous and urban radio in Argentina, Chile, and Nigeria
Authors: Cárcamo‐Huechante Luis E. , Legnani Nicole Delia 
Published: April 2010

AbstractIndigenous cultures throughout the Americas and the rest of the world have to deal with problems of cultural assimilation, migration, and dissemination of their populations. Some of them, in countries such as Argentina, Chile, and Nigeria, have developed radio programming to maintain home languages; gain access to health, education, and employment information; greet friends and relatives; and re‐create traditional culture under circumstances of modern pressures but also to open up opportunities. This article explores the capacity and awareness of these contributions in a multicultural world.
Thinking creatively is thinking critically
Authors: Gruenfeld Elizabeth 
Published: April 2010

AbstractThe Cartoneras projects aim to promote the celebration of language, culture, and creativity through a collaboration between top literary minds and cardboard collectors in Buenos Aires and Lima. They produce and publish beautiful books with hand‐painted cardboard covers that speak of the wonderful literature inside. Inspired by those projects, the Paper Picker Press (PPP) program in Boston aims to engage higher‐order thinking through an arts‐based approach to rediscovering literature through play. PPP starts with the premise that a student who is thinking creatively is also thinking critically. Creative play is critical thinking.
Aula Verde: Art as experience in community‐based environmental education
Authors: Abarca Marco A. 
Published: April 2010

AbstractAfter winning a class‐action lawsuit against unconstitutional prison conditions in Puerto Rico, Marco Abarca managed to direct part of the fine monies accumulated throughout years of litigation toward an investment that would improve the living conditions in one of the largest and poorest housing projects in Puerto Rico. With the participation of parolees and probationers, he began to transform a mosquito‐infested badland into a natural haven. Then, with the help of science educators, the group designed a workshop for elementary school children on urban ecology. As the participants organized, what developed was a community‐based, self‐employed enterprise known as Aula Verde.
Fill in the blank: Culture jamming and the advertising of agency
Authors: Lambert‐Beatty Carrie 
Published: April 2010

AbstractThis article is a review on billboard liberation and some other proj‐ects that develop the idea of talking back or over advertising in a playful and youthful way. In one of them, Ji Lee's Bubble Project, an artist places blank thought‐bubble stickers on street advertisements and waits to see what people write on them, completing the work of art and transgression. In other initiative, blank pages with the word God were placed around the city in place of advertising, inviting people to complete the prayer/complaint and to participate in a Suggestion Box, a project that collected “suggestions” from people out in the street. A review of playful and youthful ways to “rebel” against the impositions of powers like media and advertising.
Technepolitics: Who has a stake in the making of an American identity?
Authors: Green Christina Suszynski 
Published: April 2010

AbstractFollowing the lineage of Taller Alacrán, the workshop of Puerto Rican maestro Antonio Martorell, the author explores the studio workshop model as an alternative or a supplement to public school arts education models. Arguing that the production of art is a means of making one's ideas or one's community visible and that the inability, whether through education or funds, to create art can silence a person or a community, she questions whether the government is the most appropriate steward of urban public school students' arts education, given its track record of silencing artists with the reduction and removal of funds. The article offers recommendations to education professionals based on the Taller Alacrán studio system.
Rare Earth Ruthenium Gallides with the Ideal Composition Ln2Ru3Ga5 (Ln = La–Nd, Sm) crystallizing with U2Mn3Si5 (Sc2Fe3Si5) Type Structure
Authors: Jeitschko Wolfgang , Schlüter Martin 
Published: April 2010

AbstractThe rare earth ruthenium gallides Ln2Ru3Ga5 (Ln = La, Ce, Pr, Nd, Sm) were prepared by arc‐melting of cold‐pressed pellets of the elemental components. They crystallize with a tetragonal structure (P4/mnc, Z = 4) first reported for U2Mn3Si5. The crystal structures of the cerium and samarium compounds were refined from single‐crystal X‐ray data, resulting in significant deviations from the ideal compositions: Ce2Ru2.31(1)Ga5.69(1), a = 1135.10(8) pm, c = 580.58(6) pm, RF = 0.022 for 742 structure factors; Sm2Ru2.73(2)Ga5.27(2), a = 1132.95(9) pm, c = 562.71(6) pm, RF = 0.026 for 566 structure factors and 32 variable parameters each. The deviations from the ideal compositions 2:3:5 are discussed. A mixed Ru/Ga occupancy occurs only for one atomic site. The displacement parameters are relatively large for atoms with mixed occupancy within their coordination shell and small for atoms with no neighboring sites of mixed occupancy. Chemical bonding is analyzed on the basis of interatomic distances. Ln–Ga bonding is stronger than Ln–Ru bonding. Ru–Ga bonding is strong and Ru–Ru bonding is weak. The Ga–Ga interactions are of similar strength as in elemental gallium.
High‐Pressure Synthesis, Crystal Structure, and Properties of GdS2 with Thermodynamic Investigations in the Phase Diagram Gd–S
Authors: Müller Carola J. , Schwarz Ulrich , Schmidt Peer , Schnelle Walter , Doert Thomas 
Published: April 2010

AbstractGadolinium disulfide was prepared by high‐pressure synthesis at 8 GPa and 1173 K. It crystallizes in the monoclinic space group P121/a1 (No. 14) with lattice parameters a = 7.879(1) Å; b = 3.936(1) Å, c = 7.926(1) Å and β = 90.08(1)°. The crystal structure is a twofold superstructure of the aristotype ZrSSi and consists of puckered cationic [GdS]+ double slabs that are sandwiched by planar sulfur sheets containing S22– dumbbells. The thermal decomposition of GdS2 proceeds via the sulfur‐deficient polysulfides GdS1.9, GdS1.85 and GdS1.77 and eventually results in the sesquisulfide Gd2S3. GdS2 is a paramagnetic semiconductor which orders antiferromagnetically at TN = 7.7(1) K. A metamagnetic transition is observed in the magnetically ordered state.