bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrical conductivity and dielectric parameters of polyaniline doped with CuClO4 · 4BN in aqueous DMSO solvent
Authors: Ali Vazid , Kaur Raminder , Lakshmi G. B. V. S. , Kumar Anand , Kumari Kiran , Kumar Sushil 
Published: October 2011

AbstractPolyaniline has been synthesized by a chemical route. Chemical doping of polyaniline has been carried out with copper perchlorate tetrabenzonitrile (CuClO4 · 4BN) in a distilled water (H2O) + dimethylsulfoxide (DMSO) solvent system. An effort has been made to study the effect of dopant on polyaniline by electrical and dielectric measurements and Fourier transform infrared spectroscopy. Electrical conductivity and dielectric parameters such as dielectric constant, dissipation factor, and dielectric loss have been measured at different dopant concentrations and temperatures. An increase in electrical conductivity, dielectric constant, dissipation factor, and dielectric loss with an increase in the dopant concentration as well as temperature has been observed in all the samples. It has been observed that CuClO4 · 4BN dopant in polyaniline plays an important role in enhancing the conductivity of polyaniline. In addition, aqueous dimethylsulfoxide is found to be a suitable solvent for polyaniline doping with CuClO4 · 4BN. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 31: 374–379, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20260
Preparation of TiO2 epoxy nanocomposites by ultrasonic dispersion and resulting properties
Authors: Bittmann Birgit , Haupert Frank , Schlarb Alois K. 
Published: October 2011

AbstractNanocomposites gained more and more importance in the last few years because of their improved performance over the neat polymer matrix, that is, toughness and stiffness can be enhanced simultaneously by the addition of nanoparticles. However, the dispersion of these particles in the matrix remains a big challenge. In this study, two types of TiO2 nanoparticles were dispersed in two different epoxy resins by means of ultrasound. The particle size development in dependence on the dispersion time was investigated by dynamic light scattering for the different material systems. Furthermore, the influence of the viscosity on the sonication process' efficiency was analyzed. The resulting nanocomposites were tested for fracture and Charpy toughness. SEM images revealed that the improved fracture toughness properties are correlated to a rougher fracture surface, whose formation dissipates more energy. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Cure kinetics, glass transition temperature development, and dielectric spectroscopy of a low temperature cure epoxy/amine system
Authors: Dimopoulos Athanasios , Skordos Alexandros A. , Partridge Ivana K. 
Published: October 2011

AbstractThis article reports a study of the chemical cure kinetics and the development of glass transition temperature of a low temperature (40°C) curing epoxy system (MY 750/HY 5922). Differential scanning calorimetry, temperature modulated differential scanning calorimetry, and dielectric spectroscopy were utilized to characterize the curing reaction and the development of the cross‐linking network. A phenomenological model based on a double autocatalytic chemical kinetics expression was developed to simulate the cure kinetics behavior of the system, while the dependence of the glass transition temperature on the degree of cure was found to be described adequately by the Di Benedetto equation. The resulting cure kinetics showed good agreement with the experimental data under both dynamic and isothermal heating conditions with an average error in reaction rate of less than 2 × 10−3 min−1. A comparison of the dielectric response of the resin with cure kinetics showed a close correspondence between the imaginary impedance maximum and the calorimetric progress of reaction. Thus, it is demonstrated that cure kinetics modeling and monitoring procedures developed for aerospace grade epoxies are fully applicable to the study of low temperature curing epoxy resins. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of TiO2 on thermal and adhesive characteristics of poly(imide siloxane)/TiO2 hybrid films
Authors: Ko Cheng‐Jung , Tseng I‐Hsiang , Whang Wha‐Tzong , Tsai Mei‐Hui 
Published: October 2011

AbstractA novel poly(imide siloxane)/titania (PIS/TiO2) hybrid film was fabricated by sol‐gel process via in situ formation of TiO2 within PIS matrix. Poly(amic acid siloxane) (PAAS) was prepared from 4,4′‐oxydiphthalic anhydride, 2,2‐bis [4‐(4‐aminophenoxy) phenyl] propane, and α,ω‐bis(3‐aminopropyl)polydimethylsiloxane (APPS). Chelating agent, acetylacetone, and catalyst‐free polymerization were used to reduce the rate of hydrolysis of titanium alkoxide in the PAAS. X‐ray photoelectron spectroscopy data showed that the presence of APPS promotes the Ti surface composition of PIS/TiO2 hybrid film. The effects of TiO2 and APPS contents on the characteristics of surface, thermostability, coefficient of thermal expansion (CTE), and the strength of adhesion were investigated. The presence of TiO2 on the surface of the hybrid films enhanced the adhesive strength at the interface of PIS/TiO2 hybrid film and copper foil. When more TiO2 was incorporated into the PIS matrix, the PIS/TiO2 hybrid film exhibited lower CTE while retaining favorable mechanical and thermal properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Electroless silver plating on the PET fabrics modified with 3‐mercaptopropyltriethoxysilane
Authors: Lili Li , Dan Yu , Le Wang , Wei Wang 
Published: October 2011

AbstractThe feasibility of adherent silver layers onto PET fabrics by electroless plating was explored and its optimal technology for modification and electroless plating was investigated. Morphology, structure, and thermal stability of silver plating PET fabrics were characterized by scanning electric microscope (SEM), X‐ray diffraction (XRD) and thermogravitric (TG) analysis. As the silver weight on the modified fabric is 25 g/m2, the electromagnetic shielding effectiveness (SE) of silver plating PET fabric is more than 30dB at the frequency ranging from 1MHz to 5000 MHz. The results show that the silver plating PET fabric has good electrical conductivity and electromagnetic shielding property. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Miscibility enhancement on the poly(vinylchloride)/poly(methylmethacrylate) blend and characterization by inverse gas chromatography: The corrected polymer–polymer interaction parameters from the probes dependency
Authors: Al‐Ghait Mona K. , Al‐Arifi Abdullah S. , Al Andis Naser M. , AlOthman Zeid A. , Aouak Taieb 
Published: October 2011

AbstractThe miscibility of poly(vinyl chloride)/poly(methylmethacrylate) (PVC/PMMA) system was improved by introducing some pyrrolidone units into the main chains of PMMA. For that purpose, we have synthesized two copolymers of poly(methylmethacrylate‐co‐vinylpyrrolidone) (MMVP) through a radical polymerization and carried out a comparative study of PVC/MMVP blends by inverse gas chromatography (IGC) and differential scanning calorimetry (DSC) methods. The adequacy of seven n‐alkane probes has been tested to determine the thermodynamic parameters. The miscibility of the two systems has been proved by a single Tg for each blend. This observation was also confirmed by DSC analysis. To highlight the presence of interaction and its intensity between PVC and MMVP in the blends, the polymer–polymer interaction parameters have been evaluated by IGC trough which the influence of the solute has been resolved. The Schneider approach confirmed the miscibility of these systems as the K deviates positively from unity. The miscibility has been appeared highlighted from the positive difference in surface energy between the pure polymers and their blends. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of the compatibility on the morphology and properties of acrylonitrile–butadiene rubber/polypropylene thermoplastic vulcanizates
Authors: Tian Ming , Han Jibin , Wu Hanguang , Tian Hongchi , She Qingyan , Chen Wenquan , Zhang Liqun 
Published: October 2011

AbstractIn this study, the morphologies of three types of acrylonitrile–butadiene rubber (NBR)/polypropylene (PP) thermoplastic vulcanizates (TPVs) (with an NBR/PP blend ratio of 70/30) were compared. The TPVs were (1) an ultrafine fully vulcanized acrylonitrile–butadiene rubber (UFNBR)/PP TPV made by the mechanical blending of UFNBR with PP, (2) a dynamically vulcanized NBR/PP TPV without the compatibilization of maleic anhydride grafted polypropylene (MP) and amine‐terminated butadiene–acrylonitrile copolymer (ATBN), and (3) a dynamically vulcanized NBR/PP TPVs with the compatibilization of MP and ATBN. The influence of the compatibility therein on the size of the dispersed vulcanized NBR particles and the crystallization behavior of the PP in the TPVs and the resultant properties are also discussed. As indicated by Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, polarizing microscopy, dynamic mechanical thermal analysis, and rheological and mechanical testing, the compatibility was significantly improved by the reactive compatibilization of MP and ATBN, which led to a uniform and fine morphology. The compatibilization increased the crystallization rate and reduced the size of the spherulites of PP. On the other hand, it was found that the dispersed vulcanized NBR particles lowered the degree of crystallinity. The better the compatibility of the blend was, the lower the degree of crystallinity and the storage modulus were, but the higher the loss factor and the processing viscosity were. All TPVs showed almost the same oil resistance, but the TPV prepared with reactive compatibilization had the best mechanical properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis, characterization, and swelling behavior evaluation of hydrogels based on Gum ghatti and acrylamide for selective absorption of saline from different petroleum fraction–saline emulsions
Authors: Kaith Balbir Singh , Jindal Rajeev , Mittal Hemant , Kumar Kiran 
Published: October 2011

AbstractIn this research article, the synthesis of Gum ghatti and acrylamide based superabsorbents under pressure with N,N′‐methylene bisacrylamide as a crosslinker and an ascorbic acid–potassium persulfate redox pair as an initiator is reported. To study the impact of the different reaction variables on the water absorbance of the candidate polymer, different reaction parameters, including the reaction time, amount of solvent, pH of the medium, initiator ratio, pressure, and monomer and crosslinker concentrations, were optimized. The candidate polymer was characterized with different techniques, including Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, differential thermal analysis, differential thermogravimetry, and X‐ray diffraction. The crosslinked product was found to be thermally more stable than the initial backbone. The swelling capacity of the synthesized polymer was investigated in deionized water as a function of time, temperature, and pH of the swelling medium. Moreover, the effects of the ionic strengths of different cations on the swelling capacity of the candidate polymer were studied with different salt solutions. The tendency of absorbency for these hydrogels in salt solutions was found to be in the following order: Na+ > Ba2+ > Fe3+ > Sn4+ for NaCl, BaCl2, FeCl3, and SnCl4 salt solutions. Further, the candidate polymer was used for the selective absorption of saline water from different petroleum fraction–saline emulsions. The results showed that the saline absorption capacities of the hydrogels were 667, 610, 646, and 680% in kerosene–saline, diesel–saline, petrol–saline, and petroleum ether–saline emulsions, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Conformational Analysis of Bivalent Estrogen Receptor Ligands: From Intramolecular to Intermolecular Binding
Authors: Shan Min , Bujotzek Alexander , Abendroth Frank , Wellner Anja , Gust Ronald , Seitz Oliver , Weber Marcus , Haag Rainer 
Published: October 2011

AbstractThe estrogen receptor binding affinities of bivalent raloxifene ligands tethered by flexible spacers of different lengths have been evaluated in vitro. Two bivalent binding modes, intra‐ and intermolecular, were hypothesized to explain their different binding properties. The binding affinities of these bivalent ligands in an aqueous environment are influenced by their conformations, which can be determined by 2D NMR and UV spectral methods. Moreover, computer modeling and simulations were performed to explain the binding modes of these bivalent ligands and to estimate the conformational entropy difference between their unbound and bound states. It was found that bivalent ligands tethered by long spacers had weaker binding affinities because of the shielding of the binding moieties that results from their folded conformations; those tethered by short spacers had stronger affinities because they exposed their ligands to the receptor.
Oxygen Evolution in Overcharged LixNi1/3Co1/3Mn1/3O2 Electrode and Its Thermal Analysis Kinetics
Authors: Wang Haiyan , Tang Aidong , Huang Kelong 
Published: October 2011

AbstractThe oxygen evolution behavior in overcharged LiNi1/3Co1/3Mn1/3O2‐based electrode was investigated by differential scanning calorimetry and thermal gravimetric (DSC/TG). Meantime, its thermal kinetic parameters were calculated by Kissinger's and Ozawa's method. As observed by DSC/TG, two exothermic peaks at 239 and 313°C in washed cathode (4.6 V), were attributed to two steps of oxygen evolution. More importantly, the temperature of its oxygen release processes decreased obviously compared with that charged to 2.8 V. Activation energy (E) for the first and second oxygen evolution, both of which were assumed closely to be the first order reaction, between 200 and 350°C in Li0.204Ni1/3Co1/3Mn1/3O2‐based electrode were calculated as 113.63 and 158.13 kJ·mol−1, respectively and the corresponding Arrhenius pre‐exponential factors (A) of 1.05×1011 and 6.46×1013s−1 were also obtained. The different energy barrier of such two steps of oxygen evolution should probably be ascribed to the different bond energy of M–O (M=Mn, Co, Ni).
Determination of Melamine in Dairy Products and Melamine Tableware by Inhibition Electrochemiluminescent Method
Authors: Jing Wei , Lü Shuiyuan , Li Xiaojing , Jiang Xiaofen , Chen Minshi , Liang Ming , Tang Xi , Xu Caiming , Chen Jinquan 
Published: October 2011

AbstractAn electrochemiluminescent (ECL) method has been developed for the determination of melamine based on the inhibition of luminol ECL. A significant luminol ECL can be found at 1.47 V in the phosphate buffer solution at high pHs and low potential scan rates, this ECL signal can be inhibited obviously by melamine. The decrease of ECL intensity was linearly proportional to the logarithm of melamine concentration in the range of 1–100 ng/mL (R2=0.9911) and with the detection limit of 0.1 ng/mL. The method has been applied successfully to determine melamine in dairy products and melamine tableware, the recoveries were in the range of 98.5%–103.7% and 95.5%–106.0%, respectively. The mechanism of the inhibition effect was also proposed, the active oxygen (O2· −) generated from the electrooxidation of OH− reacted with luminol anion (L· −) to generate light emission, and the present of melamine can eliminate the active oxygen, which cause the decrease of the ECL intensity.
Cobalt(III) Complex [CoL3] Derived from an Asymmetric Bidentate Schiff Base Ligand L (L=(5‐Bromo‐2‐hydroxybenzyl‐2‐furylmethyl)‐imine): Synthesis, Characterization and Crystal Structure
Authors: Khalaji Aliakbar D. , Maghsodlou Rad Sepideh , Grivani Gholamhossein , Rezaei Morteza , Gotoh Kazuma , Ishida Hiroyuki 
Published: October 2011

AbstractCobalt(III) complex [CoL3], where L=(5‐bromo‐2‐hydroxybenzyl‐2‐furylmethyl)imine, has been synthesized by reacting cobalt(II) nitrate with L. The complex has been characterized by elemental analysis and FT‐IR spectroscopy. The crystal structure of [CoL3] was determined by X‐ray crystallography from single crystal data. It crystallizes in the triclinic space group$ P {\bar 1} $with unit cell parameters:a=9.6644(10) Å,b=11.5657(11) Å,c=16.5809(17) Å,α=102.833(4)°,β=102.999(3)°,γ=105.480(3)°,V=1659.9(3) Å3andZ=2. Thermal decomposition of [CoL3] was studied by thermogravimetry in order to evaluate its thermal stability and thermal decomposition pathways.
Synthesis of Novel 1,4‐Bissulfonamide Ligands for Enantioselective Addition of Diethylzinc to Aldehydes
Authors: Yang Minghua , Sun Jiangtao , Zhu Chengjian 
Published: October 2011

AbstractSeveral novel chiral sulfonamide ligands based on (1R,2S,4R,5S)‐1,4‐diamino‐2,5‐dimethylcyclohexane skeleton have been synthesized and their application in the enantioselective addition of diethylzinc to aldehydes was investigated in the presence of Ti(OiPr)4. The effect of ligands, temperature and the loading amount of ligands was studied. Under optimized conditions, enantioselective addition of diethylzinc with various aryl aldehydes and aliphatic aldehydes proceeded smoothly and afforded chiral secondary alcohols in up to 88% ee.
In(OTf)3‐Catalyzed Synthesis of Functionalized 1,5‐Benzodiazepines from o‐Phenylenediamine and Alkyl Propiolates under Solvent‐Free Reaction Conditions
Authors: Wu Haisheng , Yang Jin , Wang Lei 
Published: October 2011

AbstractA simple, environmental‐friendly, and practical method for the synthesis of benzodiazepine derivatives through a reaction of substituted o‐phenylenediamines with alkyl propiolates has been developed. The reactions generated the 1,5‐benzodiazepines in good to excellent yields in the presence of catalytic amount of In(OTf)3 under solvent‐free reaction conditions.
Expeditious and Efficient Synthesis of Benzoxazoles, Benzothiazoles, Benzimidazoles Catalyzed by Ga(OTf)3 under Solvent‐Free Conditions
Authors: Liu Juyan , Liu Qian , Xu Wei , Wang Weilu 
Published: October 2011

AbstractA new and efficient method for the synthesis of benzoxazoles, benzothiazoles, benzimidazoles from reactions of o‐substituted aminoaromatics with orthoesters in the presence of catalytic amounts of Ga(OTf)3 under solvent‐free conditions is presented. The remarkable features of this new protocol are high conversion, very short reaction times, cleaner reaction profiles under solvent‐free conditions, straight forward procedure, and use of relatively non‐toxic catalysts.
Synthesis ofN1‐3‐{(4‐Substituted aryl‐3‐chloro‐2‐oxo‐azetidine)‐iminocarbamyl}‐propyl‐6‐nitroindazole Derivatives and Their Biological Significance
Authors: Samadhiya Pushkal , Sharma Ritu , Srivastava Santosh K. , Srivastava Savitri D. 
Published: October 2011

AbstractSynthesis ofN1‐3‐{(4‐substitute daryl‐3‐chloro‐2‐oxo‐azetidine)‐iminocarbamyl}‐propyl‐6‐nitroindazole 4a–4s was conducted by a conventional method. All the compounds were synthesized and characterized by IR, 1H NMR, 13C NMR, FAB‐Mass techniques and chemical methods. All the final synthesized compounds were evaluated for their antimicrobial activity and antitubercular activity with MIC values against some selected microorganisms.
Preparation of Imprinted PVB/β‐CD Nanofiber by Electrospinning Technique and Its Selective Binding Abilities for Naringin
Authors: Ma Xiuling , Chen Zhen , Chen Xiao , Chen Riyao , Zheng Xi 
Published: October 2011

AbstractA novel molecularly imprinted composite nanofiber was prepared by a simple electrospinning technique, in which polyvinylbutyral (PVB) was chosen as matrix, β‐cyclodextrin (β‐CD) was used as a functional monomer and naringin (NG) as template molecules. After cross‐linked by hexamethylene diisocyanate (HMDI), the composite nanofiber exhibited a high specific binding capacity. The morphological structure of the nanofibers was studied by means of infrared spectrum (IR), X‐ray diffraction (XRD), and scanning electron microscopy (SEM). The β‐CD molecules were mostly homogeneously distributed within the PVB nanofiber without forming phase separated crystalline aggregates. Compared with traditional imprinted β‐CD polymer, the binding experiments demonstrated that the molecularly imprinted composite nanofiber shows the specific binding sites and the selective binding ability for NG. The molecularly imprinted nanofiber could be used at least six times without any loss in binding capacity.
Resonance Scattering Detection of Trace Hg2+ Using Aptamer‐modified AuPd Nanoalloy Probe as Catalyst
Authors: Liu Qingye , Fan Yanyan , Liang Aihui , Jiang Zhiliang 
Published: October 2011

AbstractThe 5 nm AuPd nanoalloy in mole ratio of Au:Pd=32:1 was prepared, using sodium citrate as the stabilizing agent and NaBH4 as the reductant. The AuPd nanoalloy was modified by the aptamer to prepare an aptamer‐ AuPd (AptAuPd) probe for resonance scattering (RS) detection of 5.0–1250 nmol/L Hg2+. The AptAuPd‐Hg2+ aptamer reaction solution was filtrated by membrane, and the AptAuPd in the filtrate exhibited strong catalytic effect on the slow NiP particle reaction between NiCl2 and NaH2PO2, and the NiP particles showed a RS peak at 508 nm. The RS intensity decreased when Hg2+ concentration increased. The decreased RS intensity was linear to Hg2+ concentration in the range of 0.5–1250 nmol/L. The RS assays were used to determine Hg2+ in real samples, with good results.
Activity Coefficients of NaCl in Ethylene Glycol‐Water Mixtures Using Potentiometric Measurements at 288.15, 298.15 and 308.15 K
Authors: Li Shuni , Tang Jing , Ma Yanyan , Zhai Quanguo , Jiang Yucheng , Hu Mancheng 
Published: October 2011

AbstractThe mean activity coefficients of NaCl in ethylene glycol‐water mixtures were determined in the range of w=0.10 to 0.40 ethylene glycol at 288.15, 298.15 and 308.15 K using potentiometric measurements. The Pitzer and extended Debye‐Hückel equations were used to describe the nonideal behavior of the electrolyte. Osmotic coefficients and the standard Gibbs energy of NaCl‐ethylene glycol‐water were calculated.
Application of a Novel Ant Algorithm Termed Continuous Gridded in Aidded Drug Design
Authors: Chen Guohua , Lu Yao 
Published: October 2011

AbstractAimed at solving continuous optimum parameter problems effectively in added drug design, this paper develops a novel ant algorithm termed continuous gridded ant colony (CGAC), where the spy ants are utilized to search the latent optimum grid in the domain completely and effectively. In order to test the effect, the CGAC algorithm was success in finding the best values of C and γ, when the support vector machine (SVM) was used to fit the nonlinear relationship between the numerical representation of the chemical structure and IC50. The genetic algorithm (GA) was also used to obtain the appropriate feature subset simultaneously, because feature subset selection influences the appropriate kernel parameters and vice versa. The obtained results illustrate that GA‐CGAC‐SVM models have satisfactory prediction accuracy. The best quantitative modeling results in thirteen‐descriptors model based on GA‐CGAC‐SVMr with mean‐square errors 0.397, a predicted correlation coefficient (R2) 0.842, and a cross‐validated correlation coefficient (Q2) 0.756. The best classification result was found using SVM: the percentage (%) of correct prediction based on 7‐fold cross‐validation was 90.6%. The results demonstrate that the proposed CGAC algorithm provides a new and effective method to find the optimum parameters when the SVM tool is used.
Copper‐catalyzed N‐Arylation of Imidazoles with Aryl or Heteroaryl Halides Facilitated by Dimethylglyoxime in Water
Authors: Wu Xiangmei , Hu Weiya 
Published: October 2011

AbstractA combination of CuSO4/dimethylglyoxime was found to be an efficient and inexpensive catalyst system for N‐arylation of imidazole and benzimidazole with aryl halides and heteroaryl halides in water, providing the corresponding products in moderate to good yields.