bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gel polymer electrolyte with semi‐IPN fabric for polymer lithium‐ion battery
Authors: Li Wei‐Li , Gao Yan‐Ming , Wang Shao‐Ming 
Published: December 2011

AbstractA new type of semi‐IPN gel electrolyte was prepared by thermal polymerization in this article. At first, the crosslinkable PEG200 (MXPEG) was prepared by condensation reaction, then the crosslinkable components were blent with PMMA and heated under vacuum to form polymer blends with semi‐IPN fabric. Differential scanning calorimetry and X‐ray diffraction spectroscopy were used to investigate the thermal properties and crystalline/amorphous structure of the prepared polymer blends. With semi‐IPN fabric, they present amorphous absolutely. For semi‐IPN gel electrolyte, the mechanical and the electrochemical properties are varied with the quantity of absorbed liquid electrolyte. Ion‐conductivity behavior for semi‐IPN gel electrolyte measured by means of AC impedance spectrum showed that the best data was 1.62 × 10−3S cm−1 at room temperature, and Arrhenius‐type relationship was obeyed in the temperature dependence of ionic conductivity. In addition, the electrochemical stability window of the semi‐IPN gel electrolyte was 4.6 V. All the properties showed that the prepared semi‐IPN gel electrolyte was expected to have applications of electrolyte for lithium‐ion polymer secondary batteries. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Vulcanization kinetics of butyl rubber–clay nanocomposites and its dependence on clay microstructure
Authors: Sepehri A. , Razzaghi‐Kashani M. , Ghoreishy M. H. R. 
Published: December 2011

AbstractProperties of rubber articles are very much influenced by their vulcanization characteristics. Vulcanization kinetics of isobutylene isoprene rubber (IIR) or butyl rubber, filled with three organically modified montmorillonites, having different degrees of hydrophilic nature, was investigated by oscillating disc rheometer (ODR). Microstructures of the nanocomposites were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), gas permeation, and uniaxial tension. It was shown that structure of clay ranged from moderately or highly intercalated to agglomerated structure for different organoclays. Microstructure of nanocomposites was used to explain opposite trends observed in vulcanization kinetics of them. It was shown that not only the chemical nature of the clay modifier, but also physical effects such as diffusion of vulcanizing agents in butyl rubber, limited by filler network, can alter vulcanization kinetics of this rubber. For less hydrophilic organoclays, dispersion is better, and formation of filler network structure limits diffusion and accessibility of curing agents to vulcanization sites. Two empirical models of Isayev and Ghoreishy were also employed and compared in explaining the results quantitatively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Optical expandometry: A technique to analyze the expansion kinetics of chemically blown thermoplastic foams
Authors: Solórzano Eusebio , Antunes Marcelo , Saiz‐Arroyo Cristina , Rodríguez‐Pérez Miguel A. , Velasco José I. , de Saja José A. 
Published: December 2011

AbstractA novel technique to determine in situ the free expansion kinetics of chemically foamed thermoplastic foams, so‐called optical expandometry, is presented in this work. This technique is based on the camera monitoring of a free‐foaming material placed inside a furnace. Images are acquired under special illumination conditions to facilitate the later image processing. The present article explains the experimental set‐up and the image processing methods used to determine the free volumetric expansion of different polyolefin‐based foams. The results are compared with those obtained using thermo‐mechanical analysis. In addition, several possible applications of this method are detailed, such as studying the effect of polymer rheology, foaming temperature, blowing agent content and the anisotropy of the expansion. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Cure kinetics studies of cyanate ester and bisphenol‐F epoxy blend
Authors: Brahmbhatt Priyanka , Unnikrishnan Jisha , Sudha J. D. , Pradhan Subrata 
Published: December 2011

AbstractCyanate ester and Bisphenol‐F blends with manganese acetylacetonate in nonylphenol as catalyst and cocatalysts respectively is an attractive candidate as the insulation impregnation materials for fusion grade magnets winding packs that is required to be operating in moderate irradiated environments in fusion devices like Tokamaks. The curing kinetics of this blend system as a thermosetting polymer has been investigated in this paper in detail for 60 : 40 (epoxy:ester) composition strongly driven from application interests. The order of reactions in both chemical kinetics controlled region as well as diffusion controlled regimes have been experimentally found out using Differential Scanning Calorimetric (DSC) studies. Corresponding rate constants and associated cure kinetics have been consequently determined. The second order kinetic model, as it is found, does not fit in to the epoxy‐cyanate ester reaction mechanism. The results, therefore, have been discussed in the context of widely used autocatalytic models and variable “n” kinetics models appropriate for chemical controlled region. The reaction conversion rate dα/dt of the cyanate ester‐epoxy blend is more rapid in chemical controlled regime compared to that in the diffusion controlled regime. The order of reaction is not constant throughout the reaction and is higher in chemical controlled regime. The variable “n” kinetic model has been employed to determine the hypothetical temperature (350.81 K) below which no more curing reaction would occur. The activation energy and the pre‐exponential factors have been determined in the chemical controlled regime using Arrhenius reaction. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Study on the self‐crosslinking behavior based on polychloroprene rubber and epoxidized natural rubber
Authors: Zhang Peng , Huang Guangsu , Qu Liangliang , Nie Yijing , Weng Gengsheng 
Published: December 2011

AbstractThis work has studied the impact of curing temperature and rubber compositions on the self‐crosslinking behavior of the polychloroprene rubber (CR) and epoxidized natural rubber (ENR) blend. Variation of the temperature and blending ratios, rheological results have shown a better crosslinking result at 160°C with the optimum CR ratio at 75%. Then, Arrhenius equation was applied to verify the crosslinking kinetic and first‐order kinetics has been verified. The chemical reaction routes proposed by differential scanning calorimetry have also been analyzed. Moreover, dynamic mechanical analysis and field emission scanning electron micrographs combined with energy‐dispersive X‐ray analysis were done to evaluate the phase compatibility. Based on the experimental results, a proposal “cross‐promotion” reaction is drawn to conclude the self‐crosslinking of CR and ENR. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Nylon 6/clay nanocomposite filaments and their cords
Authors: Joshi M. , Biswas D. , Sarvanan A. , Purwar Roli , Mukhopadhaya R. 
Published: December 2011

AbstractThe present study focuses on the preparation and characterization of nylon 6/clay nanocomposite filaments and their cords. Two different organo modified clays: the ditallodimethyl ammonium salt with bentonite clay (Claytone HY), a commercially available clay from M/S Southern Clay products, USA and silane modified montmorillonite clay (Silane‐MMT), synthesized in the laboratory were used to prepare nylon 6/clay nanocomposite filaments. The nanocomposite filaments were tested for tensile and creep properties and compared with nylon 6/sodium montmorillonite (Na‐MMT) nanocomposite filaments as well as neat nylon 6 filaments. The clay dispersion within the nanocomposite filaments was analyzed by using X‐ray diffraction (XRD), scanning electron (SEM), and transmission electron microscopy (TEM). The creep resistant property of all the nanocomposite filaments showed 10–19% improvement over the neat nylon filament. However, there is a marginal improvement in tenacity in case of nylon 6/silane MMT nanocomposite filament as compared to the neat nylon filament. All the nylon 6/clay nanocomposite filaments were converted into the cords and tested for various tire cord related properties such as tensile strength, rubber to cord adhesion, and fatigue resistance. The nanocomposite cords showed a significant improvement in tensile property (7–21%) as well as cord to rubber adhesion strength (34–55%) over the neat nylon cords, however, the fatigue resistance was inferior in case of nanocomposite cords. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Investigation the effect of various loads of organically modified montmorillonite on dyeing properties of polypropylene nanocomposites
Authors: Ataeefard Maryam , Moradian Siamak 
Published: December 2011

AbstractPolypropylene (PP) nanocomposites having five different loadings of an organically modified montmorillonite, mineral clay was prepared by a melt mixing technique. The resultant PP nanocomposites were then uniformly dyed using three distinct disperse dyestuffs each at three concentrations. The enhanced dyeability of PP nanocomposite was characterized by spectrophotometric measurements. Good wash fastnesses were obtained after subjection of dyeing to a reduction clear process. It was found that increasing the clay content had a significant effect on dye uptake. Tensile strength tests showed improvements in mechanical properties. Degree of crystallinity of nanocomposites at various nanoclay loadings were investigated using differential scanning calorimeter. Surface behaviors of the resultant nanocomposites as well as the extent of exfoliation and dispersion of the nanoclay particles in PP were studied by various analytical techniques such as polarized optical microscope, X‐ray diffraction, and transmission electron microscopy analytical techniques. These showed intercalate/exfoliate structures in the resultant nanocomposites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
A novel injectable and in situ crosslinked hydrogel based on hyaluronic acid and α,β‐polyaspartylhydrazide
Authors: Zhang Rui , Xue Mingyuan , Yang Jing , Tan Tianwei 
Published: December 2011

AbstractA new injectable and in situ crosslinked hydrogel, based on a hyaluronic acid (HA) derivative and α,β‐polyaspartylhydrazide (PAHy), was produced during the research. This biodegradable and high molecular weight hydrogel can be in situ crosslinked in 15 s by the condensation reaction between aldehyde and amine groups. The HA derivative carrying aldehyde (HAALD) was oxidized from HA by sodium periodate, while the synthesis of hydrogel was performed in a phosphate‐buffered saline solution (PBS) using HAALD and PAHy without addition of crosslinker or catalyst. The pH and concentration of the reaction solution, considered as the important factors of the amine‐aldehyde reaction, were changed to reveal the crosslinking rule. Thereafter, crosslinked hydrogels were characterized by gelation time, gel content, swelling ratio, and in vitro degradation. Furthermore, the modified polymers were characterized by Fourier transformed infrared (FTIR) spectroscopy to examine their structures. Results from scanning electron microscope (SEM) observations confirmed that a freeze‐dried sample revealed a porous hydrogel structure with interconnected pores. The measurement of the cell adhesion confirmed the application potential of HAALD‐PAHy hydrogels. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Application of IVIVE and PBPK modeling in prospective prediction of clinical pharmacokinetics: strategy and approach during the drug discovery phase with four case studies
Authors: Chen Yuan , Jin Jin Y. , Mukadam Sophie , Malhi Vikram , Kenny Jane R. 
Published: January 2012

ABSTRACTProspective simulations of human pharmacokinetic (PK) parameters and plasma concentration–time curves using in vitro in vivo extrapolation (IVIVE) and physiologically based pharmacokinetic (PBPK) models are becoming a vital part of the drug discovery and development process. This paper presents a strategy to deliver prospective simulations in support of clinical candidate nomination. A three stage approach of input parameter evaluation, model selection and multiple scenario simulation is utilized to predict the key components influencing human PK; absorption, distribution and clearance. The Simcyp® simulator is used to illustrate the approach and four compounds are presented as case studies. In general, the prospective predictions captured the observed clinical data well. Predicted Cmax was within 2‐fold of observed data for all compounds and AUC was within 2‐fold for all compounds following a single dose and three out of four compounds following multiple doses. Similarly, tmax was within 2‐fold of observed data for all compounds. However, Clast was less accurately captured with two of the four compounds predicting Clast within 2‐fold of observed data following a single dose. The trend in results was towards overestimation of AUC and Clast, this was particularly apparent for compound 2 for which clearance was likely underestimated via IVIVE. The prospective approach to simulating human PK using IVIVE and PBPK modeling outlined here attempts to utilize all available in silico, in vitro and in vivo preclinical data in order to determine the most appropriate assumptions to use in prospective predictions of absorption, distribution and clearance to aid clinical candidate nomination. Copyright © 2012 John Wiley & Sons, Ltd.
Application of Polyelectrolyte‐Enhanced Ultrafiltration for Rhenium Recovery from Aqueous Solutions
Authors: Zeng J. , Li S. , Sun X. , Chen X. 
Published: January 2012

AbstractPolyelectrolyte‐enhanced ultrafiltration was investigated for rhenium(VII) recovery from aqueous solutions by using polyquaternium‐6 (PQ6) as a complexing agent. The effects of the operating parameters on the permeate flux (J) and the rhenium rejection coefficient (R) were studied. In the process of concentration, J declines slowly and R is about 1. The concentrated solution was used for the decomplexation. It takes 10 min to achieve the decomplexation equilibrium at a chloride ion concentration of 100 mg L–1. The decomplexation percentage reaches 45.6 %. In the diafiltration process, rhenium is extracted effectively, and the purification of the regenerated PQ6 is satisfactory. The regenerated PQ6 was used to bind rhenium(VII). The binding capacity of the regenerated PQ6 is close to that of fresh PQ6.
tBu or not tBu?
Authors: Nilsson Lill Sten O. , Ryberg Per , Rein Tobias , Bennström Evelina , Norrby Per‐Ola 
Published: January 2012

AbstractThe regioselectivity in the palladium‐catalyzed Heck coupling reaction between an aryl halide and ethyl vinyl ether with four different phosphine ligands: PPhntBum (n=0–3, m=3−n) has been investigated both experimentally and computationally. A zigzag selectivity pattern was experimentally observed upon consecutive replacement of Ph by tBu in the phosphine ligand. Use of a standard DFT method (B3LYP) was shown to give a correct prediction of product preference. However, the trend in relative selectivity among the different ligands could not be correctly described. The use of a more recent DFT functional (M06) parameterized to reproduce dispersion interactions resulted in an improved description. For the sterically most demanding ligands, PtBu3 and PPhtBu2, unexpectedly large deviations between experimental and M06 calculated selectivities raised the question of an alternative mechanism for these ligands. In the case of PtBu3 it was found, in agreement with literature data, that the phosphine ligand could be replaced by a second halide ligand, resulting in an anionic mechanism, with a calculated selectivity in excellent agreement with experimental data. For the PPhtBu2 ligand, two mechanisms are suggested to operate in parallel, as demonstrated both by computational studies and experimental observation of halide‐dependent selectivity. A Halpern effect is observed for all phosphine ligands investigated, that is, the least stable pre‐complex results in the most abundant product.
Phase transition for potentials of high‐dimensional wells
Authors: Lin Fanghua , Pan Xing‐Bin , Wang Changyou 
Published: January 2012

AbstractFor a potential function
$\font\open=msbm10 at 10pt\def\R{\hbox{\open R}}F:\R^k \to\R _ +$
that attains its global minimum value at two disjoint compact connected submanifolds N± in $\font\open=msbm10 at 10pt\def\R{\hbox{\open R}}\R^k$, we discuss the asymptotics, as ϵ → 0, of minimizers uϵ of the singular perturbed functional ${\bf E}_\varepsilon (u) = \int_\Omega {(|\nabla u|^2 + {1 \over {\varepsilon ^2 }}F(u))} dx$
under suitable Dirichlet boundary data $\font\open=msbm10 at 10pt\def\R{\hbox{\open R}}g_\varepsilon :\partial \Omega \to\R ^k$. In the expansion of Eϵ (uϵ) with respect to ${1 \over \varepsilon }$, we identify the first‐order term by the area of the sharp interface between the two phases, an area‐minimizing hypersurface Γ, and the energy c of minimal connecting orbits between N+ and N−, and the zeroth‐order term by the energy of minimizing harmonic maps into N± both under the Dirichlet boundary condition on ∂Ω and a very interesting partially constrained boundary condition on the sharp interface Γ. © 2012 Wiley Periodicals, Inc.
Effect of Ionic Liquid on Diffusion in P123 Gel: Fluorescence Correlation Spectroscopy
Authors: Mandal Amit Kumar , Sen Mojumdar Supratik , Das Atanu Kumar , Bhattacharyya Kankan 
Published: January 2012

AbstractThe effect of two room‐temperature ionic liquids (RTILs) on the diffusion of three fluorescent dyes in the gel phase of a triblock copolymer, (PEO)20‐(PPO)70‐(PEO)20 [Pluronic P123; poly ethylene oxide (PEO), poly propylene oxide (PPO)], was studied by using fluorescence correlation spectroscopy (FCS). We used three dyes, 4‐(dicyanomethylene)‐2‐methyl‐6‐(4‐dimethylaminostyryl)‐4H‐pyran (DCM), coumarin 480 (C480), and coumarin 343 (C343). By field‐emission scanning electron microscopy (FESEM), it was observed that the macroscopic structure of the P123 gel remained unaffected upon addition of RTIL. In the absence of RTIL, the diffusion coefficient (Dt) of the hydrophobic dye DCM (1 μm2 s−1 at the core) is smaller than that of the other two hydrophilic dyes (7 μm2 s−1 for C480 and C343). On addition of RTIL, the Dt values of all of the dyes increase, indicating a decrease in local viscosity (ηeff). The ηeff of the core of the RTIL–P123 gel estimated from the Dt of DCM is lower than that of both the P123 gel (at the core η=90 cP) and RTIL (η=110 cP). It is shown that the RTIL affects the structure of the gel by modifying the size of the micellar aggregates and by penetrating the core.
An opportunity not to be missed – how do we improve postpartum screening rates for women with gestational diabetes?
Authors: Keely Erin 
Published: January 2012

SummaryThe ability to detect postpartum dysglycaemia, intervene and prevent type 2 diabetes in this high‐risk population may be the most compelling reason to diagnose gestational diabetes. However, most studies show that less than 50% of women receive any glucose screening in the postpartum period and are thus denied this opportunity. Although many have advocated for simpler testing, the 75‐g oral glucose tolerance test remains the gold standard as fasting glucose level will miss 30–40% of cases of type 2 diabetes and will not detect isolated impaired glucose tolerance. Haemoglobin A1c as a screening test has not been adequately studied.To improve postpartum screening rates, we need to increase awareness of the very high risk of type 2 diabetes, improve communication between providers, reduce fragmentation of care and introduce system factors that facilitate screening adherence. Copyright © 2012 John Wiley & Sons, Ltd.
Optical coherence tomography captures rapid hemodynamic responses to acute hypoxia in the cardiovascular system of early embryos
Authors: Gu Shi , Jenkins Michael W. , Peterson Lindsy M. , Doughman Yong‐Qiu , Rollins Andrew M. , Watanabe Michiko 
Published: January 2012

AbstractBackground: The trajectory to heart defects may start in tubular and looping heart stages when detailed analysis of form and function is difficult by currently available methods. We used a novel method, Doppler optical coherence tomography (OCT), to follow changes in cardiovascular function in quail embryos during acute hypoxic stress. Chronic fetal hypoxia is a known risk factor for congenital heart diseases (CHDs). Decreased fetal heart rates during maternal obstructive sleep apnea suggest that studying fetal heart responses under acute hypoxia is warranted. Results: We captured responses to hypoxia at the critical looping heart stages. Doppler OCT revealed detailed vitelline arterial pulsed Doppler waveforms. Embryos tolerated 1 hr of hypoxia (5%, 10%, or 15% O2), but exhibited changes including decreased systolic and increased diastolic duration in 5 min. After 5 min, slower heart rates, arrhythmic events and an increase in retrograde blood flow were observed. These changes suggested slower filling of the heart, which was confirmed by four‐dimensional Doppler imaging of the heart itself. Conclusions: Doppler OCT is well suited for rapid noninvasive screening for functional changes in avian embryos under near physiological conditions. Analysis of the accessible vitelline artery sensitively reflected changes in heart function and can be used for rapid screening. Acute hypoxia caused rapid hemodynamic changes in looping hearts and may be a concern for increased CHD risk. Developmental Dynamics 241:534–544, 2012. © 2012 Wiley Periodicals, Inc.
Gold nanoparticle‐coated capillaries for protein and peptide analysis on open‐tubular capillary electrochromatography
Authors: Hamer Mariana , Yone Angel , Rezzano Irene 
Published: January 2012

AbstractWe report a new method of immobilization of gold nanoparticles (AuNPs) on a fused‐silica capillary through covalent binding. The resulting modified capillary was applied to electrophoretic systems to improve the efficiency of separation and the selectivity of selected solutes. The immobilization of AuNPs on the capillary wall was performed in a very simple and fast way without requiring heating. The surface features of an AuNP‐coated capillary column were determined using the scanning electron microscopy. The chromatographic properties of AuNP‐coated capillaries were investigated through variation of the buffer pH and separation voltage. Effective separations of synthetic peptides mixture were obtained on the AuNP‐coated capillaries. The method shows a remarkable stability since it was reused about 900 times. The capacity factor was duplicated. Therefore, this modification is stable and can be applied to different separation purposes. A complex mixture of tryptic peptide fragments of HSA was analyzed in both the bare‐ and the AuNP‐coated capillaries. Better electrophoretic peptide profile was observed when using the AuNP‐coated capillary.