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141.
Mitra Ghassemzadeh Samira Bahemmat Masoomeh Mahmoodabadi Babak Rezaii-Rad Hassan Hosseini Monfared Effat Mottefakeri Bernhard Neumüller 《Polyhedron》2010
The reaction of AMTT (AMTT = 4-amino-3-methyl-1,2,4-triazol-5-thione, HL1) with palladium(II) chloride and triphenylphosphane as a co-ligand in acetonitrile afforded the mononuclear PdII-complex [(PPh3)Pd(HL1)Cl]Cl·2CH3CN (1). The complex [(PPh3)Pd(HL1)I]Cl·1/2H2O (2) was prepared via halogen exchange between 1 and sodium iodide in methanol/acetonitrile. The first binuclear palladium(II) complex containing singly deprotonated HL1, [(PPh3)2ClPd(L1)Pd(PPh3)Cl]Cl·1/3H2O·CH3OH (3), was prepared by the reaction of HL1 with palladium(II) chloride and triphenylphosphane in the presence of sodium acetate in methanol. 相似文献
142.
Issa Yavari Samira Arab-Salmanabadi Ali Aminkhani 《Journal of the Iranian Chemical Society》2012,9(4):503-506
An effective route to functionalized 5H-spiro[furan-2,2??-indene]-1??,3??,5-triones is described via tandem reaction of primary amines, acetylenic esters and ninhydrin. 相似文献
143.
K Shameli M Bin Ahmad EA Jaffar Al-Mulla NA Ibrahim P Shabanzadeh A Rustaiyan Y Abdollahi S Bagheri S Abdolmohammadi MS Usman M Zidan 《Molecules (Basel, Switzerland)》2012,17(7):8506-8517
Different biological methods are gaining recognition for the production of silver nanoparticles (Ag-NPs) due to their multiple applications. The use of plants in the green synthesis of nanoparticles emerges as a cost effective and eco-friendly approach. In this study the green biosynthesis of silver nanoparticles using Callicarpa maingayi stem bark extract has been reported. Characterizations of nanoparticles were done using different methods, which include; ultraviolet-visible spectroscopy (UV-Vis), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray fluorescence (EDXF) spectrometry, zeta potential measurements and Fourier transform infrared (FT-IR) spectroscopy. UV-visible spectrum of the aqueous medium containing silver nanoparticles showed absorption peak at around 456 nm. The TEM study showed that mean diameter and standard deviation for the formation of silver nanoparticles were 12.40 ± 3.27 nm. The XRD study showed that the particles are crystalline in nature, with a face centered cubic (fcc) structure. The most needed outcome of this work will be the development of value added products from Callicarpa maingayi for biomedical and nanotechnology based industries. 相似文献
144.
Siyamak S Ibrahim NA Abdolmohammadi S Yunus WM Rahman MZ 《Molecules (Basel, Switzerland)》2012,17(2):1969-1991
In this work, the oil palm empty fruit bunch (EFB) fiber was used as a source of lignocellulosic filler to fabricate a novel type of cost effective biodegradable composite, based on the aliphatic aromatic co-polyester poly(butylene adipate-co-terephtalate) PBAT (Ecoflex?), as a fully biodegradable thermoplastic polymer matrix. The aim of this research was to improve the new biocomposites' performance by chemical modification using succinic anhydride (SAH) as a coupling agent in the presence and absence of dicumyl peroxide (DCP) and benzoyl peroxide (BPO) as initiators. For the composite preparation, several blends were prepared with varying ratios of filler and matrix using the melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 (wt %) and characterized. The effects of fiber loading and coupling agent loading on the thermal properties of biodegradable polymer composites were evaluated using thermal gravimetric analysis (TGA). Scanning Electron Microscopy (SEM) was used for morphological studies. The chemical structure of the new biocomposites was also analyzed using the Fourier Transform Infrared (FTIR) spectroscopy technique. The PBAT biocomposite reinforced with 40 (wt %) of EFB fiber showed the best mechanical properties compared to the other PBAT/EFB fiber biocomposites. Biocomposite treatment with 4 (wt %) succinic anhydride (SAH) and 1 (wt %) dicumyl peroxide (DCP) improved both tensile and flexural strength as well as tensile and flexural modulus. The FTIR analyses proved the mechanical test results by presenting the evidence of successful esterification using SAH/DCP in the biocomposites' spectra. The SEM micrograph of the tensile fractured surfaces showed the improvement of fiber-matrix adhesion after using SAH. The TGA results showed that chemical modification using SAH/DCP improved the thermal stability of the PBAT/EFB biocomposite. 相似文献
145.
146.
Samira Abdolbaghi Saeed Pourmahdian Younes Saadat 《Colloid and polymer science》2014,292(5):1091-1097
In this study, the preparation of poly(acrylamide)/nanoclay organic-inorganic hybrid nanoparticles via surfactant-free inverse emulsion polymerization by using organically modified clay platelets as stabilizers was discussed. Colloidally stable inverse Pickering emulsions of aqueous acrylamide solution in cyclohexane (solvent) stabilized by hydrophobic Cloisite 20A (MMT20) were prepared. Polymerization was carried out via 2,2′-azobis(isobutyronitrile) and composite particles with an average size of ~250 nm were obtained. The effect of initiator and solvent type on the stability, size, size distribution, and morphology of the produced composite particles was examined. It was observed that in the presence of xylene as solvent, particles with bigger sizes and broader size distribution were obtained. Furthermore, using an ionic initiator resulted in a slight coagulation during polymerization and smaller particles. Moreover, the effect of various polymerization conditions such as temperature, initiator, and crosslinking agent concentration and clay content on the polymerization rate was evaluated. The experimental results showed that polymerization rate increases with an increase in polymerization temperature, crosslinking agent concentration, and initiator content. However, increasing in clay content results in a lower polymerization rate. 相似文献
147.
Zohreh Abdollahi Mariam T. Darestani Samira Ghasemi Vincent G. Gomes 《Colloid and polymer science》2014,292(10):2695-2705
Colloidal behavior of a widely used non-ionic emulsifier, sorbitan monooleate (Span80), was investigated in non-polar solvents (cyclohexane and xylene) using electrical impedance spectroscopy (EIS). The electrical characteristics of the colloidal mixtures were measured with frequency scans ranging from 1 Hz to 200 kHz. The conductances at low frequencies were found to increase with an increase in Span80 concentration. The source of conductivity for non-polar solvents using non-ionic emulsifiers is usually attributed to ionic impurities either in the Span80 or in the non-polar solvents. The measured electrical characteristics for pure Span80 and pure non-polar solvents revealed that the source of ionic conduction is impurities in Span80. It was confirmed that the ionic impurities in the non-polar solvents are in form of aggregate of ions, ion-pairs, and triple ions which is unaffected with the emulsifier concentration. Analyses using equivalent electrical circuits confirmed that the critical Maxwell-Wagner frequency is 0.6–1.8 Hz for the mixtures. The conductance-concentration profiles for the mixtures at 1 Hz showed transitions from a square root to a linear concentration dependence at the CMC. This indicated that the dissociation model holds below the CMC, while the fluctuation model applies above the CMC. The conductance profiles enabled estimates of the relative hydrophilic core radius and the fraction of charged micelles in both non-polar solvents. Figure
CMC determination of non-ionic emulsifier in non-polar solvents 相似文献
148.
Ali Zeinolabedini Hezave Samira Dorostkar Moein Nabipour Bahram Hemmateenejad 《Journal of Dispersion Science and Technology》2014,35(10):1483-1491
Ionic liquids (ILs) are a new kind of solvents that have recently gained an upsurge in attention in light of their unique potential for different applications. With respect to this, in the present study, applicability of an IL called 1-octadecyl-3-methylimidazolium chloride ([C18mim] [Cl]) as a new class of surfactant was investigated. Different interfacial tension (IFT) measurements were performed to find the effect of IL concentration and temperature on the IFT of water/crude oil system. The observed trend was explained based on mass transfer mechanisms including diffusion and convective mass transfer. In addition, the effect of rotational speed, ranging between 3000 and 9000 rpm, on the IFT was examined with the hypothesis that it can modify the convective mass transfer. Finally, since it has been reported that the Marangoni effect enhances the mass transfer flux in the surfactant solutions, two different methods of IFT measurements including the spinning drop and pendant drop methods were applied to investigate the effects of convective mass transfer on the equilibrium IFT. 相似文献
149.
Tungsten trioxide nanorods (WO3) were prepared by controlling the precipitation reaction of sodium tungstate dehydrates solution and hydrothermal process. The synthesized tungsten trioxide nanorods have been characterized by X‐ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), cyclic voltammetry (CV) and linear sweep voltammetry (LSV). Electrochemical activity for hydrogen evolution reaction (HER) on WO3 nanorods / carbon nanotube (WO3/CNT) composite electrocatalyst was first studied in acid solution (0.1 M H2SO4) at room temperature. The overall experimental results revealed that the electrocatalytic activity for HER on WO3/CNT is two order magnitude higher than those obtained with WO3 nanorods and is four times than in the case of commercial WO3 in 0.1 M H2SO4. On the other hand, the kinetic reaction mechanisms were discussed on WO3/CNT electrocatalysts in acid solution for HER. However, the rate‐determining step carries through Tafel reaction on commercial WO3, CNT, WO3 nanorods and WO3/CNT electrocatalysts in acidic solution was introduced. 相似文献
150.
We report the development of a simple and rapid colorimetric detection method for hydrazine in boiler feed water using label-free aggregation-based gold nanoparticles as probe. This assay relies upon the distance-dependent optical properties of gold nanoparticles. Hydrazine could rapidly induce the aggregation of gold nanoparticles, thereby resulting in visual color change from red to blue (or purple). The concentration of hydrazine can be determined by the naked eye or by a UV–vis spectrometer. Calibration curve was linear ranging from 1.0 × 10?11 to 1.0 × 10?7 M of hydrazine. The present limit of detection for hydrazine was 1.0 × 10?12 M. The method is rather simple, and the whole process including sample pretreatment takes only 15 min at room temperature. The merits (such as simplicity, rapidity, low cost and visual colorimetry) make the proposed method especially useful for on-site screening of hydrazine levels well in boiler feed water. 相似文献