bluuebunny/crossref_metadata_2025_split huggingface dataset:
New all solid‐state polymer electrolyte based on epoxy resin and ionic liquid for high temperature applications
Authors: Oliveira da Silva Luís Carlos , Soares Bluma Guenther 
Published: November 2017

ABSTRACTFlexible epoxy network loaded with high amount of ionic liquid (IL) 1‐decyl‐3‐methylimidazolium bromide ([DMIM]Br) has been reported by using a mixture of polyol amine as curing agent. The IL presents good electrochemical response even at 170 °C, as no evidence of redox reactions was observed. The incorporation of as high as 50 wt % of this IL within the epoxy matrix resulted in solid and flexible electrolyte with good thermal stability below 180 °C, as measured by thermogravimetric analysis and ionic conductivity of around 10−6 S cm−1 at room temperature and higher than 10−3 S cm−1 at high temperature. This electrolyte presented a prodigious potential for applications in electrochemical devices at high temperature like batteries and supercapacitors, and the flexibility of this solid electrolyte persist at low temperature because of its low glass transition temperature. Furthermore, leakage problems were not observed. Thereby, impedance spectroscopy and cyclic voltammetry were performed to characterize the electrochemical properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45838.
Interfacial modification mechanism of nanocellulose as a compatibilizer for immiscible binary poly(vinyl alcohol)/poly(ethylene oxide) blends
Authors: Yong Cheng , Mei Changtong , Guan Mingjie , Wu Qinglin , Sun Xiuxuan , Xu Bing , Wang Ke 
Published: November 2017

ABSTRACTWe undertook this study to understand reinforcement mechanism of short cellulose nanocrystals (CNCs) and long cellulose nanofibrils (CNFs) as compatibility agents for improving the interfacial miscibility of poly(vinyl alcohol) (PVA) and poly(ethylene oxide) (PEO) blends. The effects of the two cellulose nanofibers on the morphological, mechanical, and thermal properties of the polymer blends were compared systematically. The light transparency, scanning electron microscopy, and Fourier transform infrared results show that nanocellulose between PVA and PEO eliminated the negative effects generated by the immiscible interface through increased hydrogen bonding. Thermogravimetric analysis and differential scanning calorimetry results show that crystalline region reorganization around the interface facilitated the shift of the polymer blends from multiple phases to a homogeneous phase. According to the Halpin‐Kardos and Quali models, we assumed that the potential for repairing the immiscible interface would have a larger effect than the potential of reinforcement. At the same concentration, polymer blends with CNCs showed greater light transparency, strength, modulus, and crystal structure than with those with CNFs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45896.
Propolis as an antidegradant and biocidal agent for natural rubber
Authors: Kmiotek Magdalena , Bieliński Dariusz , Piotrowska Małgorzata 
Published: November 2017

ABSTRACTThe numerous applications of polymers in many areas of our lives make it necessary to protect them from aging. Increases in the safety and time of polymer material exploitation demands the application of antidegradants with broad scopes of action. In this study, crude propolis, originating from two geographical regions of Poland, was used to protect peroxide‐cured natural‐rubber vulcanizates filled with silica or carbon black from degradation by oxygen, ozone, and microorganisms. Thermogravimetry analysis confirmed the stability of propolis under the curing conditions. From vulcametric torque measurements and determinations of the mechanical properties, we determined that the incorporation of propolis did not adversely affect the performance of the natural‐rubber vulcanizates. The addition of propolis to the rubber mix made the vulcanizates resistant to thermooxidative and ozone aging and protected them from biodegradation in soil and the action of microorganisms. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45911.
Thermal and fire behavior of isophorone diisocyanate based polyurethane foams containing conventional flame retardants
Authors: Eceiza I. , Barrio A. , Martín L. , Veganzones M. A. , Fernández‐Berridi M. J. , Irusta L. 
Published: November 2017

ABSTRACTThis work reports on the fire behavior of isophorone diisocyanate‐based polyurethane foams containing different conventional flame retardants (FRs) such as melamine, ammonium polyphosphate, aluminum hydroxide, expandable graphite, and their combinations. The foams were obtained in a laboratory scale and characterized in terms of their morphology, density, thermal stability, and fire behavior. According to atomic force microscopy, the incorporation of FRs decreased the phase separated domain size. The cellular structure of the foams was examined qualitatively by scanning electron microscopy while the quantitative analysis of the surrounding skin was performed by optical microscopy and Image J. The FR containing foams showed more and smaller cells. The thermogravimetric analysis showed that the FRs had no influence in the initial degradation temperature of the foams. However, the obtained residue values were higher than the theoretical ones, indicating that there was some type of interaction between the FRs and the foams. The fire behavior of polyurethane foams was studied by the cone calorimeter and the data showed that the introduction of expandable graphite and combinations of ammonium polyphosphate/melamine to the reference foam gave rise to a significant reduction in the total heat release. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45944.
Removal of textile dyes from single and ternary solutions using poly(acrylamide‐co‐N‐methylacrylamide) grafted katira gum hydrogel
Authors: Jana Subinoy , Ray Jagabandhu , Bhanja Sunil K. , Tripathy Tridib 
Published: November 2017

ABSTRACTA novel hydrogel poly(acrylamide‐co‐poly‐N‐methylacrylamide) grafted katira gum (KG) was synthesized via free radical copolymerization using a mixture of acrylamide and N‐methylacrylamide in presence of N,N′‐methylene‐bis‐acrylamide as a crosslinking agent. A series of hydrogels (KG‐1 to KG‐6) were prepared by varying amount of acrylamide and N‐methylacryamide. Poly‐acrylamide‐g‐katira gum (PAM‐g‐KG) and poly‐N‐methylacrylamide‐g‐katira gum (PNMA‐g‐KG) hydrogels were also prepared using same crosslinking agent. Swelling characteristics of all the prepared hydrogels in water were evaluated and the hydrogel with best swelling property (KG‐6) was identified. The hydrogel KG‐6 was characterized by FTIR, X‐ray diffractometer, and scanning electron microscopy and was used for the adsorption of textile dyes namely methylene blue (MB), malachite green (MG), and congo red (CR) from single and ternary solutions. Adsorption dynamics, kinetics, isotherm, and thermodynamics of all the prepared hydrogels were studied in the ternary dye solutions. The sorption kinetics data were fitted well to pseudo‐second order and the equilibrium adsorption data were found to follow Freundlich isotherm model. The thermodynamics studies showed that the adsorption process was spontaneous and exothermic in nature. The preferential dye adsorption by the hydrogel was followed in the order MB > MG > CR. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45958.
Simultaneous determination and pharmacokinetic study of giraldoid a, giraldoid B in rat plasma after oral administration of Daphne giraldii Nitsche extracts by LC–MS/MS
Authors: Huyiligeqi  , Dong Xiaoxv , Fu Jing , Cao Sali , Yang Chunjing , You Longtai , Zhang Zhongyi , Ni Jian 
Published: November 2017

AbstractA simple sensitive LC–MS/MS method has been developed for the simultaneous determination of giraldoid A and giraldoid B in rat plasma. The method was applied to pharmacokinetics studies of the two compounds from Daphne giraldii Nitsche. Chromatographic separation was accomplished on an Acquity UPLC™ BEH C18 column (100 × 2.1 mm, 1.7 mm) by gradient elution with a flow rate of 0.2 mL min−1. The method was linear over the concentration range of 1.0–1000 ng mL−1, and the lower limits of quantification were 1.04 ± 0.10 and 1.04 ± 0.09 ng mL−1, respectively. The intra‐ and inter‐day precisions (RSD) were <10.14 and 9.96%. The extraction recovery of the analytes was acceptable. Stability studies demonstrated that the two compounds were stable in the preparation and analytical process. The maximum plasma concentration was 687.78 ± 243.62 ng mL−1 for giraldoid A and 952.38 ± 131.99 ng mL−1 for giraldoid B. The time to reach the maximum plasma concentration was 0.50 ± 0.37 h for giraldoid A and 0.50 ± 0.66 h for giraldoid B. The validated method was successfully applied to investigate the concentration–time profiles of giraldoid A and giraldoid B.
Linking Environmental Management to Environmental Performance: The Interactive Role of Industry Context
Authors: Hartmann Julia , Vachon Stephan 
Published: November 2017

AbstractIn the past, corporate sustainability scholars advocated that, for many firms, environmental management could turn into a valuable capability conferring a competitive advantage. However, little attention has been paid to the role of the industry context and its influence on the relationship between environmental management and organizational performance. In this study, we examine the effect on this relationship of three contextual variables: munificence, dynamism and complexity. Drawing on longitudinal data from 336 firms representing 30 industries, we find that munificence enhances the degree to which a firm can leverage its environmental management capabilities to improve environmental performance. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Robust handling of clumping and stiffness in wet hair animation
Authors: Kim Jong‐Hyun , Kim Wook , Kim Young Bin , Im Jaeho , Lee Jung , Kim Sun‐Jeong 
Published: November 2017

AbstractSimulating the clumping and stiffness of wet hair or fur is a challenging problem. The dynamics of wet hair or fur are characterized by clumping and stiffness at the tip, which can be seen clearly in running animals or headbanging scenes. Existing animation methods address these phenomena within preset scenarios. However, there is no consensus on a method for depicting the details of wet hair. This paper therefore proposes a new method for modeling the clumping and stiffness of wet hair or fur. Previous studies have focused on modeling the absorption of water into hair or fur, whereas this paper considers a realistic simulation of wet hair. Unlike dry hair strands, wet hair strands adjacent to one another are subject to a clumping force, gathering together and becoming more stiff as the saturation level of water increases. The proposed method builds on a surface‐tension model based on smoothed particle hydrodynamics to simulate the clumping force and to adjust the hair elasticity via stiffness constraints. The method gives realistic simulations of wet hair by maintaining the clumping force of the wet hair during movement and by simulating the stiffness of the hair in line with its water‐saturation level.
Nested PUF Proteins: Extending Target RNA Elements for Gene Regulation
Authors: Shinoda Kouki , Tsuji Shogo , Futaki Shiroh , Imanishi Miki 
Published: November 2017

AbstractRNA‐binding proteins recognizing unique sequences within large transcriptomes serve as a powerful tool to control RNA metabolism. Pumilio and fem‐3 mRNA‐binding factor (PUF) proteins are considered good candidates for such tools, because they are typically composed of eight highly homologous repeat segments and can be designed to recognize arbitrary 8 nt RNA sequences. However, a specific 8 nt RNA sequence is found at multiple sites in various RNAs in the transcriptome, making it difficult to specifically target a single RNA. Designer PUF proteins recognizing longer RNA sequences should achieve more selective binding. Here, we propose an approach for creating 16‐repeat PUFs capable of targeting a single, unique mRNA in the transcriptome. Our design is simple and involves either the tandem alignment of two PUF segments or the nesting of one PUF segment within another. Designed 16‐repeat PUFs bound to the target RNA sequence without partial recognition derived from the original 8‐repeat PUF. Furthermore, based on our strategy, expression of an endogenous mRNA was selectively and effectively modulated, demonstrating the applicability of 16‐repeat PUF proteins for regulating endogenous RNA metabolism.
Laccase‐Mediated Grafting on Biopolymers and Synthetic Polymers: A Critical Review
Authors: Slagman Sjoerd , Zuilhof Han , Franssen Maurice C. R. 
Published: November 2017

AbstractLaccase‐mediated grafting on lignocelluloses has gained considerable attention as an environmentally benign method to covalently modify wood, paper and cork. In recent decades this technique has also been employed to modify fibres with a polysaccharide backbone, such as cellulose or chitosan, to infer colouration, antimicrobial activity or antioxidant activity to the material. The scope of this approach has been further widened by researchers, who apply mediators or high redox potential laccases and those that modify synthetic polymers and proteins. In all cases, the methodology relies on one‐ or two‐electron oxidation of the surface functional groups or of the graftable molecule in solution. However, similar results can very often be achieved through simple deposition, even after extensive washing. This unintended adsorption of the active substance could have an adverse effect on the durability of the applied coating. Differentiating between actual covalent binding and adsorption is therefore essential, but proves to be challenging. This review not only covers excellent research on the topic of laccase‐mediated grafting over the last five to ten years, but also provides a critical comparison to highlight either the lack or presence of compelling evidence for covalent grafting.
Nonprecious‐metal Fe/N/C Catalysts Prepared from π‐Expanded Fe Salen Precursors toward an Efficient Oxygen Reduction Reaction
Authors: Tanaka Yuta , Onoda Akira , Okuoka Shin‐ichi , Kitano Tomoyuki , Matsumoto Koki , Sakata Takao , Yasuda Hidehiro , Hayashi Takashi 
Published: November 2017

AbstractNon‐precious metal electrocatalysts are under investigation as alternatives to platinum‐group metal electrocatalysts for the oxygen reduction reaction (ORR), which is required for cathode materials in fuel cells. Herein, we describe a new method for the synthesis of metal and nitrogen‐containing carbon (M/N/C) catalysts with high ORR activity using π‐expanded Fe(Salen) precursors. The Fe/N/C ORR catalysts were obtained by pyrolysis of a mixture of carbon support (Vulcan XC‐72R) and the iron complex precursors. The Fe/N/C catalyst prepared from N,N'‐bis(2‐hydroxy‐1‐naphthylidene)‐1,2‐phenylenediamino‐iron(III) chloride has an onset potential of 860 mV, which is positively shifted by 60 mV from that of the catalyst prepared from the simple Fe(Salen) complex. The catalyst promotes efficient four‐electron reduction in the ORR. XAFS and XPS studies reveal that the Fe/N/C catalysts have atomically‐dispersed iron active sites and that the activity depends on the high content of pyridinic nitrogen. This new methodology facilitates the design of non‐precious metal‐carbon catalysts with excellent ORR activity.
Fluorescence Commutation and Surface Photopatterning with Porphyrin Tetradithienylethene Switches
Authors: Biellmann Thomas , Galanti Agostino , Boixel Julien , Wytko Jennifer A. , Guerchais Véronique , Samorì Paolo , Weiss Jean 
Published: November 2017

AbstractFour tetradithienylethene (DTE) substituted porphyrins, the free base 1H2, and three metal derivatives (1Zn, 1Co, 1Ni), were synthesized and studied. These dyads, for which the DTE units are connected to the porphyrin's meso positions via a meta‐phenyl spacer, exhibit reversible photochromic properties in all cases, with conversion to the photostationary state (PSS) up to 88 %, as confirmed by absorption and NMR spectroscopies. Compounds 1H2 and 1Zn are fluorescent in solution and display a red emission. Upon irradiation with UV light to trigger the closing of the DTEs, the fluorescence of both the free base and zinc porphyrin was very efficiently quenched in solution. The reversible, photo‐switching of luminescence was retained in a tetra‐DTE free‐base porphyrin‐doped polystyrene film, for which photo‐patterning was demonstrated by confocal scanning microscopy. The tunable fluorescent properties of this multi‐DTE framework render this compound of interest as a photo‐rewritable fluorescent ink.
Ab Initio Ligand Field Molecular Mechanics and the Nature of Metal‐Ligand π‐Bonding in Fe(II) 2,6‐di(pyrazol‐1‐yl)pyridine Spin Crossover Complexes
Authors: Deeth Robert J. , Halcrow Malcolm A. , Kershaw Cook Laurence J. , Raithby Paul R. 
Published: November 2017

AbstractA ligand field molecular mechanics (LFMM) force field has been constructed for the spin states of [Fe(bpp)2]2+ (bpp=2,6‐di(pyrazol‐1‐yl)pyridine) and related complexes. A new charge scheme is employed which interpolates between partial charges for neutral bpp and protonated [H3bpp]3+ to achieve a target metal charge. The LFMM angular overlap model (AOM) parameters are fitted to fully ab initio d orbital energies. However, several AOM parameter sets are possible. The ambiguity is resolved by calculating the Jahn–Teller distortion mode for high spin, which indicates that in [Fe(bpp)2]2+pyridine is a π‐acceptor and pyrazole a weak π‐donor. The alternative fit, assumed previously, where both ligands act as π‐donors leads to an inconsistent distortion. LFMM optimisations in the presence of [BF4]− or [PF6]− anions are in good agreement with experiment and the model also correctly predicts the spin state energetics for 3‐pyrazolyl substituents where the interactions are mainly steric. However, for 4‐pyridyl or 4‐pyrazolyl substituents, LFMM only treats the electrostatic contribution which, for the pyridyl substituents, generates a fair correlation with the spin crossover transition temperatures, T1/2, but in the reverse sense to the dominant electronic effect. Thus, LFMM generates its smallest spin state energy difference for the substituent with the highest T1/2. One parameter set for all substituted bpp ligands is insufficient and further LFMM development will be required.
Copper‐ or Thermally Induced Divergent Outcomes: Synthesis of 4‐Methyl 2H‐Chromenes and Spiro‐4H‐Pyrazoles
Authors: Zheng Yang , Qiu Lihua , Hong Kemiao , Dong Shanliang , Xu Xinfang 
Published: November 2017

AbstractAn unprecedented divergent outcome transformation of alkyne tethered N‐sulfonyl hydrazones is reported, which provides a direct and effective access to 4‐methyl 2H‐chromene derivatives and spiro‐4H‐pyrazoles in the presence of copper catalyst or under thermal conditions, respectively. The notable features of this process include readily available starting materials, an inexpensive copper catalyst, mild reaction conditions, broad substrate scope, diverse transformations and potential applications of these generated products. Mechanistic studies indicate that the 3H‐pyrazole, which is generated via direct [3+2] cycloaddition, is the communal key intermediate of these two divergent transformations. To the best of our knowledge, this is the only example of sulfonation reaction that goes through a cascade process involving 3H‐pyrazole, which was isolated and confirmed by single crystal X‐ray diffraction analysis for the first time.
Isomerisation of Liquid‐Crystalline Tristriazolotriazines
Authors: Rieth Thorsten , Röder Nico , Lehmann Matthias , Detert Heiner 
Published: November 2017

AbstractStar‐shaped discotic liquid crystals with columnar superstructures constitute a highly interesting class of organic materials. Phenyl‐substituted tris[1,2,4]triazolo‐[1,3,5]triazine, prepared by a Huisgen reaction of phenyltetrazole and cyanuric chloride, represents an excellent core for discotic liquid crystals (DLCs). The thermal stability is not perfect, at temperatures above the clearing point, a successive threefold isomerization leads to a highly planar, C3‐symmetrical isomer, which mainly differs in the orientation of the aryl substituents to the centre of the molecule. A new class of discotic liquid crystals has been obtained: Equipped with peripheral alkoxy chains both isomers can form broad thermotropic mesophases. The optical, thermal, and physical properties were investigated by polarized optical microscopy, differential scanning calorimetry, wide‐angle X‐ray scattering, UV/Vis absorption and fluorescence spectroscopic measurements. The thermotropic properties are decisively affected by the molecular structure of the isomers, isomerisation leads to higher melting points but also the loss or even gain of mesomorphism is observed.
Absolute configuration of the diterpenoids icetexone and conacytone from Salvia ballotaeflora
Authors: Esquivel Baldomero , Burgueño‐Tapia Eleuterio , Bustos‐Brito Celia , Pérez‐Hernández Nury , Quijano Leovigildo , Joseph‐Nathan Pedro 
Published: November 2017

AbstractDetailed literature inspections regarding the diterpenoids icetexone (1) and conacytone (3) reveal that the absolute configuration (AC) of these natural occurring compounds is not rigorously proven, despite they were originally isolated in 1976. This task is now completed by single‐crystal X‐ray diffraction Flack and Hooft parameters determination after processing data collected with Cu Kα graphite monochromated radiation. The AC of both compounds is further determined by vibrational circular dichroism measurements performed on icetexone acetate (2) and conacytone triacetate (4) since the solubility of 1 and 3 is limited. Comparison of the substituent chemical shifts (SCS) induced by acetylation of 1 and 3 to afford 2 and 4, respectively, reveals that in the case of icetexone, all six SCS values of the quinone ring are in excellent agreement with the expected values, while in the case of conacytone, three agree and three do not agree due to the presence of additional acetates near the quinone ring. Density functional theory calculations performed on 3‐hydroxythymoquinone (6) and its tautomer 4‐hydroxy‐1,2‐quinone 7, on 6‐hydroxythymoquinone (8) and its tautomer ortho‐quinone 9, and on icetexone (1) and the claimed natural occurring ortho‐quinone tautomer romulogarzone (5) indicate that 2‐hydroxy‐1,4‐quinones are more stable, by some 11‐14 kcal/mol, than their 4‐hydroxy‐1,2‐quinone tautomers, and therefore, romulogarzone (5) is inexistent.
Electronic and vibrational exciton coupling in oxidized trianglimines
Authors: Szymkowiak Joanna , Kwit Marcin 
Published: November 2017

AbstractReadily available chiral trianglimine and their (poly)oxygenated congeners represent a unique class of macrocyclic rigid compounds optimal for testing electronic and vibrational circular dichroism exciton chirality methods. Electronic and vibrational circular dichroism spectra of such trianglimines are strongly affected by polar substituents in macrocycle skeletons. Double substitution by OH groups in each aromatic fragment of the macrocycle causes sign reversal of the exciton couplet in the region of the strongest UV absorption. On the other hand, electronic circular dichroism spectrum of the macrocycle having 2 methoxy groups shows 2 exciton couplets—the long‐wavelength positive and the second of the negative sign, observed at the shorter wavelengths.VCD spectra of macrocyclic imines show vibrational exciton couplets in the region of strong C=N stretches. The signs of these couplets are positive and the opposite of the diamine chirality. For trianglimine macrocycles the interpretation of VCD spectra in terms of excitons is much more convincing than for electronic circular dichroism spectra.By contrast,trans‐1,2‐diaminocyclohexane–based vicinal diimines, being a one‐third of the respective macrocycle, do not exhibit any vibrational exciton effect. Experimental data were confronted with DFT calculations. We observed good‐to‐excellent agreement between experimental and computed data.