bluuebunny/crossref_metadata_2025_split huggingface dataset:
2D MoN‐VN Heterostructure To Regulate Polysulfides for Highly Efficient Lithium‐Sulfur Batteries
Authors: Ye Chao , Jiao Yan , Jin Huanyu , Slattery Ashley D. , Davey Kenneth , Wang Haihui , Qiao Shi‐Zhang 
Published: October 2018

AbstractLithium‐sulfur batteries hold promise for next‐generation batteries. A problem, however, is rapid capacity fading. Moreover, atomic‐level understanding of the chemical interaction between sulfur host and polysulfides is poorly elucidated from a theoretical perspective. Here, a two‐dimensional (2D) heterostructured MoN‐VN is fabricated and investigated as a new model sulfur host. Theoretical calculations indicate that electronic structure of MoN can be tailored by incorporation of V. This leads to enhanced polysulfides adsorption. Additionally, in situ synchrotron X‐ray diffraction and electrochemical measurements reveal effective regulation and utilization of the polysulfides in the MoN‐VN. The MoN‐VN‐based lithium‐sulfur batteries have a capacity of 708 mA h g−1 at 2 C and a capacity decay as low as 0.068 % per cycle during 500 cycles with sulfur loading of 3.0 mg cm−2.
Schnelle Strukturaufklärung mikrokristalliner molekularer Verbindungen durch Elektronenbeugung
Authors: Gruene Tim , Wennmacher Julian T. C. , Zaubitzer Christan , Holstein Julian J. , Heidler Jonas , Fecteau‐Lefebvre Ariane , De Carlo Sacha , Müller Elisabeth , Goldie Kenneth N. , Regeni Irene , Li Teng , Santiso‐Quinones Gustavo , Steinfeld Gunther , Handschin Stephan , van Genderen Eric , van Bokhoven Jeroen A. , Clever Guido H. , Pantelic Radosav 
Published: October 2018

AbstractDerzeit publizieren Chemiker aller Fachrichtungen ca. 50 000 Kristallstrukturen pro Jahr, von denen es sich bei der überwältigenden Mehrheit um Röntgenstrukturen handelt. Wir setzen Elektronen‐ statt Röntgenbeugung ein, um die Struktur zweier molekularer Verbindungen zu bestimmen. Zu diesem Zweck wurde ein EIGER‐Hybridpixeldetektor an ein Transmissionselektronenmikroskop angebaut und so ein Elektronendiffraktometer konstruiert. Die Struktur eines neuen Methylenblauderivates wurde aus einem Kristall kleiner als 1×2 μm2 mit einer Auflösung von 0.9 Å bestimmt. Mehrere tausend Wirkstoffe sind nur als submikrokristallines Pulver verfügbar. Um das Potenzial für die pharmazeutische Industrie zu verdeutlichen, haben wir die Struktur eines Wirkstoffs direkt aus einer Tablette bestimmt. Wir demonstrieren, dass Elektronenkristallographie die Röntgenkristallographie ergänzt und die Methode der Wahl ist für alle ungelösten Strukturen von submikrometergroßen Kristallen. Die Größe der Kristalle ist uns hier wichtig als Kriterium für die Elektronenbeugung.
A Long‐Lived Halogen‐Bonding Anion Triple Helicate Accommodates Rapid Guest Exchange
Authors: Massena Casey J. , Decato Daniel A. , Berryman Orion B. 
Published: October 2018

AbstractAnion‐templated helical structures are emerging as a dynamic and tractable class of supramolecules that exhibit anion‐switchable self‐assembly. We present the first kinetic studies of an anion helicate by utilizing halogen‐bonding m‐arylene‐ethynylene oligomers. These ligands formed high‐fidelity triple helicates in solution with surprisingly long lifetimes on the order of seconds even at elevated temperatures. We propose an associative ligand‐exchange mechanism that proceeded slowly on the same timescale. In contrast, intrachannel anion exchange occurred rapidly within milliseconds or faster as determined by stopped‐flow visible spectroscopy. Additionally, the helicate accommodated bromide in solution and the solid state, while the thermodynamic stability of the triplex favored larger halide ions (bromide≈iodide≫chloride). Taken together, we elucidate a new class of kinetically stable helicates. These anion‐switchable triplexes maintain their architectures while accommodating fast intrachannel guest exchange.
Free Fatty‐Acid Generation and Lipid Oxidation during Dry‐Grind Corn Ethanol Fermentation
Authors: Brothers Brett , Wang Hui , Wang Tong 
Published: October 2018

AbstractThe formation of free fatty acid (FFA) is an undesirable change during dry‐grind corn ethanol fermentation because it negatively affects biodiesel transformation. The primary objective of this work was to determine where in the process FFA is generated using laboratory‐scale simulation experiments. TLC and GC were used to quantify FFA in the extracted total lipids. Values obtained from FFA determination by titration were also compared with those obtained from TLC‐GC. Results indicate that FFA generation is due to an incremental increase at each step in the process, particularly at the early slurrying and liquefaction stage, and also likely during the continuous backset. Furthermore, laboratory‐based fermentations indicate that the oxidation of linoleic acid in the FFA fraction and possibly in the oil increased the FFA level determined using the titration method. Industrial oil samples collected were shown to be highly oxidized and this led to an overestimation of FFA by 15–24% using the titration method compared to TLC‐GC due to the formation of a secondary oxidation product, acids. Such a discrepancy in FFA quantification and the level of lipid oxidation have not been seen in the literature.
Aqueously soluble semi‐aromatic copolyamides with dual‐functional groups as sizing agent
Authors: Qi X. , Wang W. , Zhang J. , Yan C. , Zhu Y. , Zhang F. 
Published: October 2018

ABSTRACTA series of novel aqueously soluble semi‐aromatic (co)polyamides, poly[(ethylenedioxy)bis(ethylene) terephthalamide]‐ran‐poly[(ethylenedioxy)bis(ethylene) (2,5‐dihydroxy‐3,6‐diallyl)terephthalamide] (CRPAOT‐x), were prepared via the solid‐state Claisen rearrangement reaction of poly[(ethylenedioxy)bis(ethylene) terephthalamide]‐ran‐poly[(ethylenedioxy)bis(ethylene) 2,5‐bis(allyloxy)terephthalamide] (APAOT‐x), where x (= 0, 13, 25, 50, 75, and 100) represents the molar fraction of allyloxy containing unit. APAOT‐x was obtained through the interfacial copolymerization of terephthaloyl chloride, 2,5‐bis(allyloxy)terephthaloyl chloride, and 2,2′‐(ethylenedioxy)bis(ethylamine). The reaction conditions including reactant concentration, temperature, and solvent were optimized. The chemical structures of the target (co)polyamides and their precursors were characterized by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopies. The incorporation of hydrophilic (ethylenedioxy)bis(ethylene) units greatly improved the polymer solubility. CRPAOT‐x dissolved not only in polar organic solvents such as dimethylformamide, dimethyl sulfoxide, and N‐methyl pyrrolidone but also in ammonia water. Due to the presence of hydroxyl groups and oxygen‐rich aliphatic units, CRPAOT‐x showed excellent affinity toward epoxy resins. The microbond test indicated that the aramid fibers sized by these dual‐functional polymers exhibited remarkably enhanced interfacial shear strength in epoxy matrices. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47132.
The effect of brominated epoxy on epoxy/phenolic reactive blends
Authors: Sheinbaum L. , Sheinbaum M. , Weizman O. , Dodiuk H. , Kenig S. 
Published: October 2018

ABSTRACTInnovative reactive blends containing epoxy and brominated epoxy (BE) incorporated with resole‐type phenolic were studied with the aim to elucidate the curing kinetics and the final thermomechanical characteristics of this unique system. Curing kinetics was investigated by means of the activation energy determined using differential scanning calorimetry (DSC ) at various heating rates analyzed by the Arrhenius equation. Both DSC and Fourier transform infrared revealed that bromine elimination at elevated temperatures (above 220 °C) had lowered the activation energy in the case of BE containing phenolic blends. The thermomechanical properties showed that the addition of conventional epoxy to resole decreased its thermal properties and modulus compared to neat resole. Distinctively, BE/resole blends exhibited increased glass‐transition temperature, compared to diglycidyl ether of bisphenol A/resole blends in combination with higher elongation and toughness compared to neat resole. It was concluded that BE/epoxy resin/phenolic reactive systems offer highTg, mechanical properties and toughness and hence are applicable for structural adhesives and for matrices of polymer‐fiber composites. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 47172.
Anisotropic polyimide aerogels fabricated by directional freezing
Authors: Wu Peng , Zhang Bin , Yu Zhi , Zou Huawei , Liu Pengbo 
Published: October 2018

ABSTRACTIn this study, we adapted a simple, low‐cost, and environmentally friendly method to fabricate anisotropic polyimide (PI) aerogels. During directional freezing of an aqueous poly(amic acid) ammonium salt solution from the profile to the center axis of the cylindrical mold, the ice crystals preferred to grow along the radial direction of the cylindrical mold. After the ice crystals were sublimated by freeze drying, an anisotropic pore structure was formed in the aerogels. The prepared PI aerogels had lower densities (0.04–0.22 g/cm3) and higher porosities (84–97%) and exhibited anisotropy in both their pore structures and properties. Their compressive modulus and strength in the horizontal direction were both higher than those in the vertical direction, and they also had good compression recovery in the vertical direction. Moreover, their heat‐transfer performance also exhibited anisotropy. The heat transfer in the horizontal direction of the aerogels was much faster than that in the vertical direction. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47179.
Carbon foam production from bio‐based polyols of liquefied spruce tree sawdust: Effects of biomass/solvent mass ratio and pyrolytic oil addition
Authors: Ozbay Nurgul , Yargic Adife Seyda 
Published: October 2018

ABSTRACTOne of the next‐generation structural materials is carbon foam. Porous materials have become an intriguing alternative material to traditional ones in many utilizations based on their light weight and incomparable properties. Coal or fossil oils are conventionally used to produce pitch, phenolic resin, and polyurethane as carbon foam precursor. Biomass liquefaction is a developing technique to convert biomass resources into the industrial chemicals. In this study, spruce tree sawdust was liquefied under mild conditions with different solvent type (phenol or phenol + bio‐oil mixture). The unique aspect of this work is the synthesis of bio‐polyol when pyrolytic oil is used as an alternative to phenol in the solvolysis reaction and its evaluation in carbon foam production with multilayer graphene sheets. Therewithal, the ratios of biomass to solvent were 1/3 as well as 1/5, and the comparison of product characteristics is another originality of the study. Slow pyrolysis of spruce tree sawdust was performed under static atmosphere and bio‐oil was characterized with elemental analysis and various chromatographic and spectroscopic techniques. The effect of mass ratio of biomass/solvent on the characteristics of porous resin foams synthesized from liquefaction product. Obtained resin foams were carbonized at 400 °C, and then activated at 800 °C under nitrogen atmosphere. Structure evaluation of resin foams, carbonized foams, and activated carbon foams from liquefied spruce tree sawdust was investigated by using elemental analysis, x‐ray diffraction, nitrogen adsorption/desorption isotherms, scanning electron microscopy, true/bulk density, and compressive strength tests. Although the surface area values decreased when bio‐oil was added as a solvent, it was determined that the compression strengths of the produced carbon foams (up to 1.080 MPa) were higher than that of conventional phenolic foams. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47185.
2,5‐Furandicarboxylic acid as a sustainable alternative to isophthalic acid for synthesis of amorphous poly(ethylene terephthalate) copolyester with enhanced performance
Authors: Sun Liyuan , Zhang Yajie , Wang Jinggang , Liu Fei , Jia Zhen , Liu Xiaoqing , Zhu Jin 
Published: October 2018

ABSTRACT2,5‐furandicarboxylic acid (FDCA), a bio‐based monomer, was taken as a sustainable alternative to isophthalic acid (IPA) for the modification of poly(ethylene terephthalate) (PET). Results showed that FDCA was more effective than IPA in terms of reducing the crystallization activity of PET, because FDCA is more rigid and highly polar, which will hinder the PET chain packing during crystallization process. Moreover, modification of PET with FDCA resulted in copolyester with higher glass transition temperature, higher tensile modulus, better optical clarity, and gas barrier property, compared to those of IPA. With the addition of 20 mol % FDCA, the resulted copolyester poly(ethylene 2,5‐furandicarboxylate‐co‐ethylene terephthalate) (PEFT 20) was able to keep high transparency even after being annealed at 110 °C for 40 min. However, when 20 mol % of IPA was added, poly(ethylene isophthalate‐co‐ethylene terephthalate) (PEIT20) easily turned opaque under the same heat treatment. Therefore, less amount of FDCA was required in order to obtain the PET copolyester with better performance. The result indicated that FDCA had great potential to substitute IPA for the modification of PET from the point of view of industrial application. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47186.
In situpreparation of reduced graphene oxide reinforced acrylic rubber by self‐assembly
Authors: Wang Jing , Li Hongqiang , Zhang Lin , Lai Xuejun , Wu Wenjian , Zeng Xingrong 
Published: October 2018

ABSTRACTReduced graphene oxide reinforced acrylic rubber (ACM/RGO) wasin situprepared via self‐assembly method in the presence of hydrazine hydrate as reducing agent. X‐ray diffraction and X‐ray photoelectron spectroscopy confirmed the chemical structure of ACM/RGO, and transmission electron microscope and scanning electron microscope demonstrated that RGO was uniformly dispersed in ACM matrix. Due to the barrier role of RGO sheets, the resistances to heat and water of ACM/RGO were obviously improved. Furthermore, the mechanical properties were also largely affected by the incorporation of RGO. With 2 parts per hundred rubber of RGO, the tensile strength and Shore A hardness of ACM/RGO reached 18.8 MPa and 73, and the elongation at break maintained at 236%. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 47187.
Nitrile rubber/sliding graft copolymer damping material with significantly improved strength and damping performance
Authors: Wang Junjun , Geng Xiaoyan , Wang Wencai , Zhang Liqun , Zhao Xiuying , Nishi Toshio 
Published: October 2018

ABSTRACTNitrile rubber (NBR)/sliding graft copolymer (SGC) composites with significantly improved strength and damping property are successfully prepared. SGC is a novel kind of supramolecular material with sliding crosslink junctions. The micromorphology analyses of NBR/SGC composites indicate that the SGC phase with particle size less than 500 nm is fairly uniformly dispersed in the NBR matrix. As SGC content increases, the loss factors (tan δ) of NBR/SGC composites increase gradually. Specifically, the tan δ of NBR/SGC (100/40) is about 1.2 times higher than that of pristine NBR rubber. The tensile strength and elongation at break of NBR/SGC composites are unexpectedly improved after the addition of SGC. The significantly improved damping performance and tensile strength can be ascribed to the pulley effect of SGC and the strong interfacial hydrogen bonds between SGC and NBR. The high damping performance and good mechanical strength make the NBR/SGC composite a promising high‐performance damping material. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47188.
Behavior of zinc complex of bis(N‐phenylsulfonyldithiocarbimate) as accelerator in the vulcanization of nitrile rubber compounds
Authors: de Arruda Mariana Moura Sampaio , Cunha Leandro Marcos Gomes , Visconte Leila Lea Yuan , Rubinger Mayura Marques Magalhães , Oliveira Marcelo Ribeiro Leite , Pacheco Elen Beatriz Acordi Vasques 
Published: October 2018

ABSTRACTChemical complexes containing N‐R‐sulfonyldithiocarbimates have been looked at as potential substitutes for N‐R‐dithiocarbamates as accelerators for the vulcanization process, especially due to their structural similarities and, most importantly, for the capability of this last compound to not form nitrosamines during the vulcanization process. The zinc complex bis(N‐phenylsulfonyldithiocarbimate)zincate(II) (n‐PSC) of tetrabutylammonium was tested in nitrile rubber compositions and its performance compared with bis(4‐methylphenylsulfonyldithiocarbimate)zincate(II) (MPSC) of tetrabutylammonium and also with commercial accelerators. The complex n‐PSC imparted values of cure times intermediate between those given by ultrafast and moderate commercial accelerators. Nitrile rubber compounded with n‐PSC also presented similar mechanical properties as compared with the commercial accelerators except for an inferior aging resistance. Concerning the two complexes, n‐PSC was found to promote better properties such as optimum cure time, crosslink density, and elongation at break as compared with MPSC. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47211.
Facilitation of biological motion processing by group‐based autism specific social skills training
Authors: Luckhardt Christina , Kröger Anne , Elsuni Leyla , Cholemkery Hannah , Bender Stephan , Freitag Christine M. 
Published: October 2018

Abnormalities in neurophysiological correlates of social perception are a well‐known feature of autism spectrum disorder (ASD). However, little is known if and how ASD specific behavioral interventions may affect neural processing in ASD. The aim of the current study was to investigate for the first time, whether the group‐based social skills training SOSTA‐FRA would elicit changes in neurophysiological correlates of social perception in high‐functioning ASD individuals aged 8–17 years. Event‐related potentials (ERPs) of a facial emotion recognition (FER) and a biological motion perception task were examined. ERPs were compared between a randomized intervention and a treatment as usual group at three time points (baseline, post‐intervention, and at 3 months follow‐up). A reduction of P100 amplitude in the right hemisphere and a trend toward reduced N200 latency in the biological motion task were found after the training only in the intervention group, whereas behavioral performance remained stable. Change in N200 latencies and parent‐rated social responsiveness showed small but statistically nonsignificant correlations. No changes were observed regarding FER. Results indicate that the intervention changed neural correlates of social perception in ASD. Especially neural correlates of biological motion perception, which is an important prerequisite for successful social interaction, were sensitive to change. ERPs of social perception tasks that are impaired in ASD can well be used to objectively measure neural processing improvement by behavioral intervention. Autism Res 2018, 11: 1376–1387. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryIt is well known that people with autism spectrum disorder (ASD) process social information differently than other people and that these differences can also be seen in their brain activity. We also know that behavioral therapies, such as group‐based social skills trainings can help people with ASD improve their behavior. But it is unclear how therapy changes social processing in the brain. The aim of our study was therefore to examine how neural processing of social stimuli changed after behavioral intervention. Comparing a group of children and adolescents that received the group‐based social skills training SOSTA‐FRA to a control group we found that the neural processing of human motion became faster and involved less brain resources after the intervention, while behavioral performance remained stable. No changes were seen for the processing of emotional facial expressions. We recommend that future studies should also analyze changes in brain function as well as behavioral changes as a secondary therapy outcome parameter.
Novel Lithium‐Ion Capacitor Based on TiSb2 as Negative Electrode: The Role of Mass Ratio towards High Energy‐to‐Power Densities and Long Cyclability
Authors: Arnaiz María , Gómez‐Cámer Juan L. , Mijangos Federico , Rojo Teófilo , Goikolea Eider , Ajuria Jon 
Published: October 2018

AbstractIn this work lithium ion capacitors (LICs) built using a TiSb2 alloy as the negative electrode and activated carbon (AC) derived from recycled olive pits biomass as the positive electrode are reported. TiSb2 shows high capacity (360 mAh g−1 at 10 C) and excellent rate capability performance together with exceptional volumetric features, enabling its use as a promising candidate for high power requiring technologies. So far, to the best of our knowledge, this is the first Sb alloy‐based LIC ever reported. In order to maximize the output performance, the influence of the mass ratio of the active materials (TiSb2 : AC) is studied. The best TiSb2‐based LIC is able to deliver an energy density as high as 167 Wh kgAM−1 (78 Wh dm−3) at 115 W kgAM−1 (53 W dm−3), more than a 6‐fold increase with respect to its EDLC counterpart. Under high power demanding situations, i. e., 11 kW kgAM−1 (6 kW dm−3), it retains up to 90 Wh kgAM−1 (48 Wh dm−3), which is among the best reported values for LICs. In addition, the device with the most appropriate mass ratio presents an encouraging 80 % retention of the initial capacitance after 10000 charge‐discharge cycles at tdischarge=11 s.
Reinvestigation of an O‐Salicylaldehyde Ester Functional Group in Aqueous Buffer and Discovery of a Coumarin Scaffold Probe for Selective N‐Terminal Cysteine Labeling
Authors: Murale Dhiraj P. , Hong Seong Cheol , Jang Se‐young , Lee Jun‐Seok 
Published: October 2018

AbstractMany intracellular proteins are metabolically unstable, and their half‐life was known to be controlled by the “N‐end rule,” that is, the N‐terminal residue controlled protein stability. To visualize or measure the cellular stability of a protein, depending on the N‐terminal residues, attention is being paid to the development of selective labeling methods for individual N‐terminal amino acids. However, there are only a limited number of functional groups available for specific N‐terminal amino acid labeling in a biological environment. Herein, we report a re‐examination of salicylaldehyde ester for selective N‐terminal residue tagging. Salicylaldehyde ester has been used for chemical ligation to N‐terminal serine or threonine under pyridine/acetic acid conditions. Inspired by previous selective serine/threonine labeling, N‐terminal labeling of salicylaldehyde ester in aqueous buffer has been examined by using boron‐dipyrromethene (BODIPY), rhodamine, and coumarin probes. Surprisingly, the selectivity not only significantly differed, depending on the fluorophore incorporated in salicylaldehyde, but was also perturbed by the addition of a small fraction of phosphate‐buffered saline. In particular, the coumarin‐based salicylaldehyde ester probe showed notable selectivity against N‐terminal cysteine under aqueous buffer conditions. This result reveals the serendipitous discovery of a new N‐terminal cysteine labeling strategy.