Dimerization of 1-butene via zirconium-based Ziegler-Natta catalyst

A zirconium-based Ziegler-Natta catalytic system has been tested in the dimerization of 1-butene. It was found that the concentration of Et2AlCl, Ph3P and PhONa as well as the reaction temperature had great influences on the activity and selectivity of the catalyst. Under the optimum reaction conditions, the conversion of 1-butene is 91.9%, and the selectivity of dimers is 76.7%. Basic ligands such as Ph3P and PhONa can inhibit isomerization of 1-butene to 2-butene effectively. In addition, the metal hydride mechanism was also suggested and some indirect evidence was obtained in favor of this mechanism.

Crystallographic and electrochemical characteristics of melt-spun Ti–Zr–Ni–Y alloys

Ti45Zr30Ni25Yx (x = 1, 3, 5 and 7) alloys were prepared by melt-spinning at wheel velocity of 20 m s(-1). The effect of additive Y on phase structure and electrochemical performance of melt-spun alloys was investigated. Ti45Zr30Ni25Yx melt-spun alloys were composed of I-phase and amorphous phase. T

Crystallographic and electrochemical characteristics of melt-spun Ti-Zr-Ni-La alloys

Ti-based icosahedral quasicrystalline phase (I-phase) exhibited excellent hydrogen storage property for special structure. Unfortunately, the application as the negative electrode material of the nickel-metal hydride batteries was limited due to the poor electrochemical kinetics. Meanwhile, rare-earth element was beneficial to the electrochemical properties of Ti, Zr-based alloy.

Structure and electrochemical characteristics of melted composite Ti0.10Zr0.15V0.35Cr0.10Ni0.30-LaNi5 hydrogen storage alloys

The structure and electrochemical characteristics of melted composite Ti0.10Zr0.15V0.35Cr0.10Ni0.30+x% LaNi5 (x=0, 1, 5 and 10) hydrogen storage alloys have been investigated systematically. XRD shows that the matrix phase structure of V-based solid solution phase with a BCC structure and C14 Laves phase with hexagonal structure is not changed after adding LaNi5 alloy. However, the amount of the secondary phase increases with increasing LaNi5 content. Field emission scanning electron microscopy-energy dispersive spectroscopy (FESEM-EDS) shows that the C14 Laves phase contains more Zr and the white lard phase has a composition close to (Zr, Ti)(V, Cr, Ni, La)(2).

Structures and electrochemical characteristics of Ti0.26Zr0.07V0.24Mn0.1Ni0.33Mox (x=0-0.1) hydrogen storage alloys

Microstructures and electrochemical properties of Ti0.26Zr0.07V0.21Mn0.1Ni0.33Mox (x=0,0.025,0.05,0.075, 0.10) electrode alloys have been investigated. The results of XRD analysis show that the alloys are mainly composed of V-based solid solution phase with body centered cubic (bcc) structure and C14 Laves phase with hexagonal structure. The addition of Mo element can imp ove the activation characteristics, maximum discharge capacity and cyclic durability for the electrode alloys

Dynamic mechanical properties of gel polymer electrolytes containing ionic liquid

The copolymer of acrylonitrile (AN), methyl methacrylate (MMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) is synthesized in 1-butyl-3-methylimidazolium tetrafluoroborate (BMImBF(4)). The dynamic mechanical properties of the resulting gel polymer electrolytes containing ionic liquid are measured.

Rare-Earth Metal Bis(alkyl)s Supported by a Quinolinyl Anilido-Imine Ligand: Synthesis and Catalysis on Living Polymerization of epsilon-Caprolactone

The tridentate ligand N-(2-((2,6-diisopropylphenylimino)methyl)phenyl)quinolin-8-amine (HL) was prepared. Treatment of HL with 1 equiv of Ln(CH2SiMe3)(3)(THF)(2) afforded the corresponding rare-earth metal bis(alkyl) complexes LLn(CH2SiMe3)(2)(THF)(n) (Ln = Sc, n = 0 (1); Y, n = 1 (2); Lu, n = 0 (3)) in high yields. Variable-temperature H-1 NMR spectral analysis showed that these complexes were fluxional at room temperature. Complexes 1 and 3 were THF-free, where the metal center adopted a square-pyramidal geometry, while in 2 the metal center generated a distorted octahedral geometry owing to the coordination of a THF molecule.

Effects of thermal annealing on polymer photovoltaic cells with buffer layers and in situ formation of interfacial layer for enhancing power conversion efficiency

We have investigated the effects of thermal annealing before and after cathode deposition on poly(3-hexylthiophene)(P3HT)/[6,6]-phenyl C61-butyric acid methyl ester (PCBM) blend photovoltaic cells with different cathode buffer layers. The introduction of cathode buffer layer such as lithium fluoride (LiF) and calcium oxide (CaO) in pre-annealing cells can increase the open-circuit voltage (V-oc) and the power conversion efficiency (PCE). Post thermal annealing after cathode deposition further enhanced the PCE of the cells with LiF/Al cathode.

Crystallographic and electrochemical characteristics of Ti45Zr35Ni13Pd7 melt-spun alloys

Ti45Zr35Ni13Pd7 alloys are prepared by melt spinning at different cooling rates (v). The phase structure and electrochemical hydrogen storage performance are investigated. When U is 10 m/s, the alloy consists of icosahedral quasicrystalline phase (I-phase), C14 Laves phase and a little amorphous phase. When v increases to 20 or 30 m/s, a mixed structure of I-phase and amorphous phase is formed. Maximum discharge capacity of alloy electrode decreases from 156 mAh/g (v = 10 m/s) to 139 mAh/g (v = 30 m/s) with increasing v. High-rate discharge ability at the discharge current density of 240 mA/g decreases monotonically from 61.2% (v = 10 m/s) to 56.8% (v = 30 m/s).

Crystallographic and electrochemical characteristics of Ti-Zr-Ni-Pd quasicrystalline alloys

Ti45Zr35Ni20-xPdx (x = 0, 1, 3, 5 and 7, at%) alloys were prepared by melt-spinning. The phase structure and electrochemical hydrogen storage performances of melt-spun alloys were investigated. The melt-spun alloys were icosahedral quasicrystalline phase, and the quasi-lattice constant increased with increasing x value. The maximum discharge capacity of alloy electrodes increased from 79 mAh/g (x = 0) to 148 mAh/g (x = 7). High-rate dis-chargeability and cycling stability were also enhanced with the increase of Pd content. The improvement in the electrochemical hydrogen storage characteristics may be ascribed to better electrochemical activity and oxidation resistance of Pd than that of Ni.

Effect of La-Mg-based alloy addition on structure and electrochemical characteristics of Ti0.10Zr0.15V0.35Cr0.10Ni0.30 hydrogen storage alloy

Effect of La-Mg-based alloy (AB(5)) addition on Structure and electrochemical characteristics of Ti0.10Zr0.15V0.35Cr0.10Ni0.30 hydrogen storage alloy has been investigated systematically. XRD shows that the matrix phase structure is not changed after adding AB(5) alloy, however, the amount of the secondary phase increases with increasing AB(5) alloy content. The electrochemical measurements show that the plateau pressure Ti0.10Zr0.15V0.35Cr0.10Ni0.30 + x% La0.85Mg0.25Ni4.5Co0.35Al0.15 (X = 0, 1, 5, 10, 20) hydrogen storage alloys increase with increasing x, and the width of the pressure plateau first increases when x increases from 0 to 5 and then decreases as x increases further, and the maximum discharge capacity changes in the same trend.

Synthesis, characterization and optical property of flower-like indium tin sulfide nanostructures

We report a simple method for novel flower-like In4SnS8 nanostructure synthesis. A flower-like In4SnS8 nanostructure was synthesized via a one-pot hydrothermal route using the biomolecule L-cysteine as a sulfur source. The structure was characterized using X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption analysis and photoluminescence spectra. This flower-like structure consists of crosslinked nanoflakes and possesses good thermostability and a high BET surface area.

Effect of AB(5) alloy on Ti0.10Zr0.15V0.35Cr0.10Ni0.30 hydrogen storage alloy

The structure and electrochemical characteristics of melted composite Ti0.10Zr0.15V0.35Cr0.10Ni0.30 + x% LaNi4Al0.4Mn0.3Co0.3 (x = 0, 1, 5) hydrogen storage alloys have been investigated systematically. XRD shows that though the main phase of the matrix alloy remains unchanged after LaNi4Al0.4Mn0.3Co0.3 alloy is added, a new specimen is formed. The amount of the new specimen increases with increasing x. SEM-EDS analysis indicates that the V-based solid solution phase is mainly composed of V, Cr and Ni; C14 Laves phase is mainly composed of Ni, Zr and V; the new specimen containing La is mainly composed of Zr, V and Ni. The electrochemical measurements suggest that the activation performance, the low temperature discharge ability, the high rate discharge ability and the cyclic stability of composite alloy electrodes increase greatly with the growth of x.

Effect of substitution of chromium for nickel on structure and electrochemical characteristic of Ti0.26Zr0.07V0.24Mn0.1Ni0.33 multi-phase hydrogen storage alloy

Ti-Zr-V-Mn-Ni-based multi-component alloys demonstrate high discharge capacity in KOH electrolyte. However, the drastic decrease in their discharge capacities makes them unsuitable for use as negative electrode material in the Ni/MH battery. In present work, Ni is partially replaced by Cr in the Ti-Zr-V-Mn-Ni-based alloys to improve their cycle life. The effects of Cr substitution on microstructures and the electrochemical characteristics of the alloys are investigated. It is found that Cr substitution is very effective to improve the cyclic durability of the alloys although the discharge capacity decreases with changing x from 0.05 to 0.20. Some kinetic performances have been also investigated using electrochemical impedance spectroscopy (EIS) and potentiostatic discharge technique.

Ethylene Polymerization by the New Chromium Catalysts Based on Amino-Pyrrolide Ligands

A series of amino-pyrrolide ligands (1-4a) and their derivatives aminothiophene ligand (5a), amino-indole ligand (6a) were prepared. Chromium catalysts, which were generated in situ by mixing the ligands with CrCl3(thf)(3) in toluene, were tested for ethylene polymerization. The preliminary screening results revealed that the tridentate amino-pyrrolide ligands containing soft pendant donor, 3a, 4a/CrCl3(thf)(3) systems displayed high catalytic activities towards ethylene polymerization in the presence of modified methyaluminoxane. The electronic and steric factors attached to the ligand backbone significantly affected both the catalyst activity and the polymer molecular weight. Complex 4b was obtained by the reaction of CrCl3(thf)(3) with one equivalent of the lithium salts of 4a, which was the most efficient ligand among the tested ones. The effect of polymerization parameters such as cocatalyst concentration, ethylene pressure, reaction temperature, and time on polymerization behavior were investigated in detail. The resulting polymer obtained by 4b display wax-like and possess linear structure, low molecular weight, and unimodal distribution.