bluuebunny/crossref_metadata_2025_split huggingface dataset:
Search for simulants of sulfur mustard through sorption studies in elastomers
Authors: Parmar Toral , Dubey Vinita , Agarwal D. D. 
Published: February 2007

AbstractWith an aim to probe some of the safe and commercially available nonsulfur chemicals as simulants of sulfur mustard for testing of protective materials, the sorption of bis(2‐chloroethyl) ether (2‐CEE), 1,6‐dichlorohexane, bis(4‐chlorobutyl) ether, n‐octane (OCT), dimethyl methylphosphonate, and ethylene glycol through butyl rubber (IIR) and polyisoprene (PI) rubber was studied at 30 ± 2°C using gravimetric method. Among these compounds, sorption of OCT was maximum while bis(4‐chlorobutyl) ether was sorbed least. The sorption of dimethyl methylphosphonate was intermediate between 2‐CEE and 1,6‐dichlorohexane. With the exception of OCT/IIR, OCT/PI, and 2‐CEE/PI, all other simulant/elastomer systems showed non‐Fickian behavior, implying the potential of OCT as a model compound. The diffusivity of OCT was investigated in IIR and PI; the diffusion coefficient values for OCT/IIR and OCT/PI systems differed by one order of magnitude, being 6.95 × 10−15 m2/s and 3.74 × 10−14 m2/s, respectively, indicating the relative impermeability of IIR. The magnitude and dynamics of sorption in OCT/IIR as a function of its concentration and the amount of filler were further studied using the automated gravimetric analyzer. Incorporation of carbon black in IIR further reduced the extent of sorption, thereby implying an improvement in barrier performance. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1801–1806, 2007
Poly(methylmethacrylate)‐poly(vinyl pyrrolidone) microspheres as drug delivery systems: Indomethacin/cefadroxil loading and in vitro release study
Authors: Sairam M. , Ramesh Babu V. , Krishna Rao K. S. V. , Aminabhavi T. M. 
Published: February 2007

AbstractPoly(methylmethacrylate)‐poly(vinyl pyrrolidone) (PMMA‐PVP) microspheres loaded with cefadroxil (water‐soluble) and indomethacin (water‐insoluble) drugs have been prepared by the dispersion polymerization technique using PVP as a steric stabilizer. Microspheres have been characterized by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and X‐ray diffraction (X‐RD) studies. DSC studies indicated coating of PVP onto PMMA microspheres. SEM suggested the formation of microspheres in the size of around 5 μm. X‐RD confirmed that drug has been highly dispersed in polymer particles. Higher encapsulation efficiency of up to 84% was achieved for hydrophobic drug, indomethacin than for hydrophilic cefadroxil. In vitro release studies performed in pH 7.4 phosphate buffer saline indicated that release of indomethacin was controlled up to 12 h, whereas cefadroxil was released in a controlled manner up to 10 h. During in vitro release, properties of both the drugs remained unaltered. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1860–1865, 2007
Preparation of hydroxyapatite/Ca‐alginate composite microspheres via inverse suspension crosslinked method
Authors: Liu Chao , Ji Xiujie , Zhao Kongyin , Cheng Guoxiang 
Published: February 2007

AbstractComposite microspheres were prepared with hydroxyapatite (HA) and Na‐alginate (ALG) via inverse suspension crosslinked method (ISCM). Chloroform/hexane (1 : 2 (volume)) was used as continuous phase, ethyl cellulose (EC) as disperser, mixture of HA powder and ALG solution as dispersed phase, and calcium chloride as crosslinking agent. Morphology of the composite microspheres and HA distribution state were observed by optical microscope. According to the compositions studied, the sample with 0.2 g of EC gives the best continuous phase. The sample with 25 mL/min of adding speed and 120 r/min of stirring speed gives the best adding and stirring conditions. Two kind of the composite microspheres of 50/50 and 70/30 HA/ALG were prepared via ISCM. They are with specific gravity of 1.06 and 1.15, and water content of 88 and 81%, respectively. The size of the dried microspheres is mainly in the range of 125–425 μm. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2034–2038, 2007
Electrochemical synthesis of polyaniline and its comparison with chemically synthesized polyaniline
Authors: Bhadra Sambhu , Singha Nikhil K. , Khastgir Dipak 
Published: February 2007

AbstractThe synthesis of polyaniline (PAni) powder was carried out from 0.15M of aniline and 1M of HCl in distilled water at room temperature in a single compartment electrochemical cell. The PAni was again synthesized chemically keeping the composition and temperature same as electrochemical process but adding equimolar amount of ammonium peroxydisulfate as an oxidizing agent. Then the PAni obtained from these two methods were characterized by the conductivity, solubility, X‐ray, FTIR, TGA, UV, and SEM, and compared. Result shows that the electrochemically synthesized PAni (ECS‐PAni) has somewhat lower conductivity, higher solubility, more benzenoid rings than quinoid rings, lower crystallinity, higher band energy, and higher particle size than that of chemically synthesized PAni (CS‐PAni). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1900–1904, 2007
Preparation and characterization of surfactant‐free stimuli‐sensitive microgel dispersions
Authors: Griffin James M. , Robb Ian , Bismarck Alexander 
Published: February 2007

AbstractA surfactant‐free method to produce responsive polymer microgels is introduced. As an example, poly(methacrylic acid) hydrogels with varying crosslinking density have been synthesized in bulk and then chopped using a high shear mechanical cutter to form microgel particles dispersed in water. The mechanical cutting technique enables the concentration and particle size distribution of the microgel suspensions to be easily controlled, therefore making the rheology of the suspensions tuneable. The particle size distribution of the dispersions, characterized using light scattering, was dependent on the speed and duration of mechanical cutting. The particle size distribution also depended on the degree of crosslinking of the hydrogel. The higher the crosslinking density, the lower the average mean diameter of the resulting microgel particles. The lower the crosslinking density of the hydrogel, the larger the difference between the maximum and minimum particle size. The time to complete swelling of the particles upon change in pH was measured to be up to 45 s, depending on the particle size. The rheology of the resulting suspensions as a function of pH was investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 104: 1912–1919, 2007
Electropolymerization of PoPD from aqueous solutions of sodium dodecyl benzene sulfonate at conducting glass electrode
Authors: Zhang Xiu‐Hua , Wang Shi‐Min , Wu Jie , Liu Xian‐Jie 
Published: February 2007

AbstractElectropolymerization of poly‐(o‐phenylenediamine) (PoPD) film was performed in a micellar aqueous solution containing sodium dodecyl benzene sulfate (SDBS) by cyclic voltammetry at conducting glass electrode. The experimental results showed that the anionic micelle, i.e., SDBS, can greatly catalyze the electropolymerization reaction of oPD and reduce its oxidation potential from 0.97 to 0.74 V (vs. saturated calomel electrode). In the anionic micellar media, the local concentration of o‐phenylenediamine (oPD) on the surface of electrode may be increased, and the oPD cation radicals are more stabilized in the hydrophobic microcircumstance of micelle, which is available to avoid hydrolysis degradation of PoPD and enhance the stability of the PoPD film. The spectroscopy and morphology of the films were characterized by FTIR spectroscopy and atomic force microscopy, respectively. The results suggested the possible presence of columnar structures when the electropolymerization is performed in the micellar medium. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1928–1932, 2007
Removal of chromium from waste water using polyaniline
Authors: Eisazadeh Hossein 
Published: February 2007

AbstractOne of the suitable methods for removing heavy metals from waste water is using surface adsorption process. In this article, the preparation of polyaniline and its composites as adsorbents are discussed and the capability of separating chromium from industrial waste water is studied. The results were compared with anthracite and cation exchangers such as purolite‐302 and amberjet. The observations indicated that the purolite and amberjet have the most chromium removal percentage. Also the role of polyaniline and its composite as adsorbents were studied. The results show that the percentage of chromium removal has increased in polyaniline/poly(vinyl alcohol) composite. Furthermore, the adsorption percentage is related to the surface morphology, type of adsorbents, and their weight ratios. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1964–1967, 2007
The effect of different sterilization procedures on chitosan dried powder
Authors: Yang Yu‐Min , Zhao Ya‐Hong , Liu Xiao‐Hua , Ding Fei , Gu Xiao‐Song 
Published: February 2007

AbstractThe aim of this study was to investigate the effects induced by three different sterilization methods [steam, γ‐radiation, and ethylene oxide (EO)] with different dose or time period of sterilization by means of Fourier transform infrared spectroscopy, X‐ray diffraction, and assessments of molecular weight and degree of deacetylation. The experiment results clearly showed that the steam sterilization greatly darkened the color of chitosan powder; γ‐irradiation strongly depolymerized the chitosan especially at irradiation dose above 10 kGy; and exposure to EO led to minor change in crystallinity and network structure of chitosan powder. Therefore, these three methods have their respective advantages and disadvantages, suggesting that the selection of the sterilization method of chitosan should depend upon the specific requirement of the final application. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1968–1972, 2007
Surface modification of radiation‐grafted polymer films and membranes by crosslinking
Authors: Schnyder Bernhard , Rager Timo 
Published: February 2007

AbstractThe surface composition of radiation‐grafted FEP‐g‐poly(styrene‐co‐divinylbenzene) films and its sulfonated analogues was investigated by X‐ray photoelectron spectroscopy. These investigations demonstrate that the surface composition is strongly influenced by the degree of crosslinking of the polystyrene phase. In the absence of a crosslinker, the surface concentration of the grafting component was high and could even exceed the calculated average concentration in the volume of the polymer. With increasing crosslinker concentration, the surface concentration of the grafting component decreased rapidly and became close to zero for crosslinker concentrations above 2% in the monomer mixture. The effect was most pronounced in the case of grafted films and weaker in the case of sulfonated membranes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1973–1978, 2007
Effect of the variation in the weight percentage of the loading and the reduction in the nanosizes of CaSO4 on the mechanical and thermal properties of styrene–butadiene rubber
Authors: Mishra S. , Shimpi N. G. 
Published: February 2007

AbstractThe incorporation of fillers into elastomers has profound effects on the mechanical, physical, and thermal properties of the nanocomposites that form. In this study, styrene–butadiene rubber as a matrix was reinforced separately with 10‐, 15‐, or 23‐nm CaSO4, which was synthesized by an in situ deposition technique. The mixing and compounding were performed on a two‐roll mill, and sheets were prepared in a compression‐molding machine. Properties such as the swelling index, specific gravity, tensile strength, elongation at break, modulus at 300% elongation, Young's modulus, hardness, and abrasion resistance were measured. The morphology of the rubber nanocomposites was also performed with scanning electron microscopy to study the dispersion of the nanofiller in the rubber matrix. The thermal decomposition of the rubber nanocomposites was studied with thermogravimetric analysis, and the results were compared with those of commercial CaSO4‐filled styrene–butadiene rubber. A reduction in the nanosizes of CaSO4 led to an enhancement of the mechanical, physical, and thermal properties of the rubber nanocomposites. Above a 10 wt % filler loading, the styrene–butadiene rubber showed a reduction in all properties. This effect was observed because of the agglomeration of the nanoparticles in the rubber matrix. The thermodynamic parameters were also studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2018–2026, 2007
Morphology, structure, and conductivity of polypyrrole prepared in the presence of mixed surfactants in aqueous solutions
Authors: Xing Shuangxi , Zhao Guoku 
Published: February 2007

AbstractPolypyrrole (PPy) was prepared from different mixed‐surfactant solutions with ammonium persulfate as an oxidant. Three types of combinations were selected, including cationic/anionic, cationic/nonionic, and anionic/nonionic mixed‐surfactant solutions. The surfactants used in the experiments included cetyltrimethylammonium bromide (cationic surfactant), sodium dodecyl sulfate (anionic surfactant), sodium dodecyl sulfonic acid salt (anionic surfactant), poly(vinyl pyrrolidone) (nonionic surfactant), and poly(ethylene glycol) (nonionic surfactant). The morphology, structure, and conductivity of the resulting PPy were investigated in detail with scanning electron microscopy, Fourier transform infrared spectra, and the typical four‐probe method, respectively. The results showed that the interaction between the different surfactants and the interaction between the surfactants and the polymer influenced the morphology, structure, and conductivity of the resulting polymer to different degrees. The cationic surfactant favored the formation of nanofibers, the addition of anionic surfactants produced agglomeration but enhanced the doping level and conductivity, and the presence of a nonionic surfactant weakened the interaction between the other surfactant and the polymer in the system. In comparison with the results for monosurfactant solutions, the polymerization of pyrrole in mixed‐surfactant solutions could modulate the morphologies of PPy, which ranged from nanofibers of different lengths to nanoparticles showing various states of aggregation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1987–1996, 2007
Synthesis of crosslinked superabsorbent carboxymethyl cellulose/acrylamide hydrogels through electron‐beam irradiation
Authors: Ibrahim Sayeda M. , El Salmawi Kariman M. , Zahran A. H. 
Published: February 2007

AbstractA study on the possibility of the preparation of superabsorbent hydrogels based on crosslinked carboxymethyl cellulose polymer and acrylamide monomer through electron‐beam irradiation was carried out. The effects of the irradiation dose and polymer–monomer compositions on the crosslinking density were studied. The hydrophilic properties of the superabsorbent hydrogels were identified by the swelling percentage. The prepared hydrogels had higher swelling in distilled water than in salt solutions. Moreover, the hydrogels exhibited the highest swelling at pH 7. Also, increasing the temperature up to 50°C caused an increase in the swelling. The thermal properties of the hydrogels were characterized with thermogravimetric analysis. The use of the prepared superabsorbent hydrogels for the growth of rice was also investigated through the water‐retention property. The water retention in the soil was enhanced with the hydrogels. Superabsorbent hydrogels based on carboxymethyl cellulose polymer and acrylamide monomer could be considered as water‐managing materials for agriculture and horticulture in desert and drought‐prone areas. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2003–2008, 2007
The publishing dynamics of catastrophic events
Authors: W. Weessies Kathleen 
Published: February 2007

AbstractThis article studies the effect that two major disasters, the Three Mile Island nuclear disaster and the Chernobyl nuclear disaster, had on the publishing world. We expect consumer publishing to concentrate on major events as they unfold. The technical and scholarly publishing world, however, is believed to progress and develop in conjunction with the growth of science, as established in bibliometric laws. Articles about these disasters were tracked in four bibliographic databases representing scholarly, technical‐scholarly, technical, and consumer literature. Several analyses of the data revealed that each body of literature responds in its own way to disasters and anniversaries of events affect publishing, other than government‐sponsored research. More focused databases have a more highly correlated response to disasters than broad‐based databases. Comparison to two previously published studies of fast‐growing literatures reveals that while some measures are consistent, disasters experience participation from a larger number of researchers with publications spread across a broader base of journal titles.
Chemoselective C(sp3)H Bond Activation for the Preparation of Condensed N‐Heterocycles
Authors: Ren Hongjun , Li Zhuo , Knochel Paul 
Published: February 2007

AbstractCondensed N‐heterocycles were prepared by using CH activation reactions catalyzed by Pd(OAc)2 (5 mol %) and (p‐tolyl)3P (10 mol %). The key step of these ring closures is chemoselective intramolecular CH activation of the methyl group at position 2 of the pyrrole ring. Functionalized 9H‐pyrrolo[1,2‐a]indoles and pyrrolo[1,2‐f]phenanthridine derivatives were prepared in good yields. The preparation of some complex N‐heterocycles by using successive reactions is also described.
Recent Progress in the Catalytic Synthesis of Imidazoles
Authors: Kamijo Shin , Yamamoto Yoshinori 
Published: February 2007

AbstractImidazole is one of the important heteroaromatic compounds that have found a broad range of uses in, for example, pharmaceutical and industrial applications. Several conventional methodologies for the synthesis of imidazole rings are known; however, they are limited in terms of substrate generality and are not always efficient. Recent studies toward the development of catalytic reactions have brought significant improvements to the preparation of imidazoles. This Focus Review highlights the very recent progress in the catalytic synthesis of imidazoles, particularly those involving the formation of five‐membered ring cores.
VCD spectroscopic and molecular dynamics analysis of the Trp‐cage miniprotein TC5b
Authors: Copps Jeffrey , Murphy Richard F. , Lovas Sándor 
Published: February 2007

AbstractTC5b is a 20 residue polypeptide notable for its compact tertiary structure, a rarity for a short peptide. This structure is due to the “Trp‐cage“ motif, an association of aromatic, Pro, and Gly residues. The structure of TC5b has been fully characterized by NMR and electronic circular dichroism (ECD) studies, but has never been studied with vibrational circular dichroism (VCD) spectroscopy, which may reveal finer structure. In this study, we examine the VCD spectra of TC5b to characterize the spectroscopic signature of the peptide and its comprising structural elements. TC5b exhibited a negative‐positive‐negative triplet which is associated with α‐helical structure in deuterated solvents but also signs of a polyproline II (PPII) helix in the amide I' region. Detection of this element was complicated by the aforementioned triplet form, as well as by an upfrequency shift in PPII helical elements due to the use of the deuterated organic solvents DMSO‐d6 and TFE‐d1. Nevertheless, while ECD spectra showed only α‐helical structure for TC5b, VCD spectroscopy revealed a more complex structure which was in agreement with NMR results. VCD spectroscopy also showed a rapid conformational change of the peptide at temperatures above 35°C in D2O and in aqueous solvent with greater than 75% DMSO‐d6 content. Molecular dynamics (MD) simulations to investigate this latter effect of DMSO‐d6 on TC5b were conducted in DMSO and 50% (v/v) DMSO in H2O. In DMSO unfolding of the peptide was rapid while in 50% (v/v) DMSO in H2O the unfolding was more gradual. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 88: 427–437, 2007.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
‘Everybody's entitled to their own opinion’: ideological dilemmas of liberal individualism and active citizenship
Authors: Condor Susan , Gibson Stephen 
Published: February 2007

AbstractConversational interview accounts were used to explore everyday understandings of political participation on the part of young white adults in England. Analysis focussed on dilemmatic tensions within respondents' accounts between values of active citizenship and norms of liberal individualism. Respondents could represent community membership as engendering rights to political participation, whilst also arguing that identification with local or national community militates against the formulation of genuine personal attitudes and rational political judgement. Respondents could represent political participation as a civic responsibility, whilst also casting political campaigning as an illegitimate attempt to impose personal opinions on to others. Formal citizenship education did not appear to promote norms of political engagement but rather lent substance to the argument that political decision‐making should be based on the rational application of technical knowledge rather than on public opinion or moral principle. In conclusion we question whether everyday understandings of responsible citizenship necessarily entail injunctions to political action. Copyright © 2007 John Wiley & Sons, Ltd.
UK students and sex work: current knowledge and research issues
Authors: Roberts Ron , Bergström Sandra , La Rooy David 
Published: February 2007

AbstractAvailable evidence, largely arecdotal suggests that students are turning to quick ways of making money such as work in the sex industry in order to balance their finances, a trend seen in other countries with similar student support and tuition fee policies. Further research is urgently needed to understand the scale of student involvement in sex work and to clarify our understanding of the factors that influence the decision to engage in it. Unfortunately a number of methodological, practical and political problems stand in the way of such research. These are discussed together with preliminary findings from an exploratory study. Copyright © 2007 John Wiley & Sons, Ltd.
Control and Selectivity of Photosensitized Singlet Oxygen Production: Challenges in Complex Biological Systems
Authors: Cló Emiliano , Snyder John W. , Ogilby Peter R. , Gothelf Kurt V. 
Published: February 2007

AbstractSinglet molecular oxygen is a reactive oxygen species that plays an important role in a number of biological processes, both as a signalling agent and as an intermediate involved in oxidative degradation reactions. Singlet oxygen is commonly generated by the so‐called photosensitization process wherein a light‐absorbing molecule, the sensitizer, transfers its energy of excitation to ground‐state oxygen to make singlet oxygen. This process forms the basis of photodynamic therapy, for example, where light, a sensitizer, and oxygen are used to initiate cell death and ultimately destroy undesired tissue. Although the photosensitized production of singlet oxygen has been studied and used in biologically pertinent systems for years, the photoinitiated behaviour is often indiscriminate and difficult to control. In this Concept, we discuss new ideas and results in which spatial and temporal control of photosensitized singlet oxygen production can be implemented through the incorporation of the sensitizer into a conjugate system that selectively responds to certain triggers or stimuli.