Synthesis, Characterization and Vulcanizing Properties of Rare Earth Complexes with 2-Mercaptobenthiazole

Eight complexes of rare earth with 2 mercaptobenthiazole, RELCl 2·RE(OH) 3· x H 2O (L=2 mercaptobenthiazole, RE= La～Gd, Y, except for Pm, x =0, 2～4), were synthesized in unhydrous ethanol and characterized by elemental analyses, IR spectra and thermal analyses. The results show that the ligand is coordinated to the RE ion through both the exocyclic sulfur and the thiazole nitrogen. The vulcanizing properties of the La complex as accelerator were studied in the traditional tire rubber, which indicate that the cross linked rubber accelerated by the rare earth complex has good physical and dynamic mechanical properties by comparison.

First-principles study of interphase Ni_3Sn in Sn-Ni alloy for anode of lithium ion battery

This paper investigates the mechanism of Li insertion into interphase Ni3Sn in Ni-Sn alloy for the anode of lithium ion battery by means of the first-principles plane-wave pseudopotential. Compared with other phases, it is found that the Ni3Sn has larger relative expansion ratio and lower electrochemical potential, with its specific plateaus voltage around 0.3 eV when lithium atoms are filled in all octahedral interstitial sites, and the relative expansion ratio increasing dramatically when the lithiated phase transits from octahedral interstitial sites to tetrahedral interstitial sites. So this phase is a devastating phase for whole alloy electrode materials.

Preparation of Sn nano-film by direct current magnetron sputtering and its performance as anode of lithium ion battery

Sn thin film on Cu foil substrate as the anode of lithium ion battery was prepared by direct current magnetron sputtering(DCMS). The surface morphology,composition and thickness and the electrochemical behaviors of the prepared Sn thin film were characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD),inductively coupled plasma atomic emission spectrometry(ICP),cyclic voltammetry(CV) and galvanostatic charge/ discharge(GC) measurements. It is found that the Sn film is consists of pure Sn with an average particle diameter of 100 nm. The thickness of the film is about 320 nm. The initial lithium insertion capacity of the Sn film is 771 mA·h/g. The reversible capacity of the film is 570 mA·h/g and kept at 270 mA·h/g after 20 cycles.

Transient Spectroscopic Properties of [60]Fullerene-Containing Cyclic Sulphoxide

The properties of the triplet excited state of [60]fullerene-containing cyclic sulphoxide have been investigated by time-resolved absorption spectroscopy. Transient absorption bands of [60]fullerene-containing cyclic sulphoxide showed two decay-components, which were attributed to triplet excited states of different spin multiplicity. The properties of photoexcited states of [60]fullerene-containing cyclic sulphoxide are also reported.

Regio-and Diasteroselectivity of Rhodium-catalyzed Ring Opening Reaction of Oxabenzonorbornadienes with Heteroatom Nucleophiles

A new rhodium catalyzed ring opening reaction of oxabenzonorbornadienes and its derivatives was described. This reaction forms a new carbon-nitrogen bond via an intermolecular allylic displacement of the bridgehead oxygen with a piperazine's derivatives, which proceeds with very high regioselectivity.

A Study of the Background Absorption of Chitosan in the Graphite Furnace Atomic Absorption Spectrometry

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Structure and electrochemical properties of hypo-stoichiometric hydro-gen storage alloys prepared by twin-roller rapid quenching process

The stoichiometric alloy MlB5.0 and the hypo-stoichiometric alloy MlB4.85 were prepared by twin-roller rapid quenching process, and their structure and electrochemical properties were studied. The results of XRD show that both of the alloys have a typical single-phase hexagonal CaCus-type structure. The cell volume of the hylpo-stoichiometric alloy M1B4.85 is slightly larger than that of the stoichiometric alloy M1B5.0, although its lattice constant cla is smaller. Under 2 C discharging rate, i.e. 640 mA/g, the M1B4.85 has a discharge capacity of 320 mAh/g, which is higher than that of the M1Bs.o, 312 mAh/g. Nevertheless, the capacities of the M1B4.85 and the M1Bs.o decline 24.7% and 20.2% after 400 cycles, respectively. The relationship of electrochemical performances of the alloys with their structures is discussed.

Dielectric Spectroscopy Study on Vesicles of CTAB/SDBS System

Amphiphilic molecules can form into different structures, such as micelle, microemulsion, vesicle, liposome, liquid crystals, and so on by self-associating. The Dielectric Spectroscopy (DS) method has been applied to the systems of micelle and microemulsion successfully. For the first time the author put the method to the system of vesicle of CTAB/SDBS. The experiments show clear dielectric relaxation and the results were discussed primarily.

Evaluation of Transient Absorption Spectra of N, N, N, N- Tetra - ( p -methylphenyl ) - 4, 4- diamino - 1, 1- diphenyl Ether ( TPDAE ) for Electron Transfer from TPDAE to Fullerenes ( C_(60) / C_(70) ) by Laser Flash Photolysis

Photoinduced electron transfer processes between fullerenes (C60 / C70) and N, N, N, N tetra - ( p-methylphenyl ) - 4, 4 diamino - 1, 1- diphenyl ether ( TPDAE ) have been studied by nanosecond laser flash photolysis. Quantum yields and rate constants of electron transfer from TPDAE to excited triplet state of fullerenes (C60 / C70 ) in benzonitrile have been evaluated by observing the transient absorption bands in the near-IR region where the excited triplet state, radical anion of fullerenes ( C60 / C70 ) and radical cations of TPDAE appear.

High-Efficiency Saturated Red Bilayer Light-Emitting Diodes： Comparative Studies with Devices from Blend of the Same Light-Emitting Polymers

High-efficient saturated red light-emitting diodes are realized based on a bilayer of phenyl-substituted poly [p- phenylene vinylene] derivative （P-PPV） and copolymer （PFO-DBT15） of 9,9-dioctylfluorene （DOFF） and 4,7-di- 2-thienyl-2,1,3-benzothiadiazole （DBT）. External electrolurninescent （EL） quantum efficiency of PFO-DBT15 is increased from 1.6% for a single-layer device to 4.7% for the bilayer device by insertion of a P-PPV layer between PEDOT （polyethylene dioxythiophene-polystyrene sulfonic acid） and PFFO-DBT15 at the current density of 35 mA/cm^2. The luminescence efficiency reaches 0.83 cd/A, and the Commission Internationale de PEelairage coordinates （CIE） become nearly x = 0.700 and y = 0.300. In comparison with the devices from PFFO-DBT15 and P-PPV blend films, the P-PPV/PFO-DBT15 bilayer device shows higher EL quantum efficiency and better stability under high current density, The improved device performance can be attributed to the charge-confinement effect at the interface of the P-PPV/PFO-DBT15 bilayer structure.

Extraction Mechanism of Rare Earths with Sec-Octylphenoxy Acetic Acid by Two-Phase Titration Technique

The compositions of the extracted complexes of La, Gd, Er and Y with sec octyl phenoxy acetic acid in heptane and the related apparent extraction equilibrium constants K M were determined using two phase titration technique. The stoichiometric compounds for La, Gd, Er and Y should be LaA 3·2.5HA, GdA 3·3HA, ErA 3·3.1HA and YA 3·4.3HA respectively. And their p K M are 3.43, 3.46, 3.08 and 2.58 respectively.

Performance of electrolyte with dimethyl methyl phosphonate as flame-retardant additive

To improve the safety of lithium-ion batteries,dimethyl methyl phosphonate(DMMP) was used as a flame-retardant additive in a LiPF6 electrolyte solution. The flammability and thermal stability of DMMP-containing electrolyte was investigated by means of burning test and accelerating rate calorimeter. It was found that the flammability and self-heat rate of the electrolyte can be reduced by the addition of DMMP. On the other hand,the electrochemical performances of graphite/LiCoO2 cells become slightly worse after using DMMP additive in the electrolyte. This alleviated trade-off between electrolyte flammability,thermal stability,and cell performance provides a possibility to formulate a nonflammable electrolyte containing DMMP and improve the electrolyte thermal stability with a minimal sacrifice in performance.

THE STUDY OF INTERACTION OF SOLID-LIQUID ADSORPTION SYSTEM BY USING THE FLOW INJECTION-SPECTROPHOTOMETRY SYSTEM

The flow injection analysis was firstly used for studying a solid-liquid adsorption system, and the dynamics process in the adsorption of dyestuff with regenerable chitin was traced by an online method of flow injection-spectrophotometry. Experimental results indicate that there is a linearization between the tested signals and the height of peaks with reciprocity coefficient 0.9999 by using the flow injection-spectrophotometry system to study the dynamics adsorption process in solidliquid system. The method shows a good stability and reproducibility. It provides a new method for the studies on adsorption dynamics in solid- liquid system.

Electrodeposition preparation of Nafion-Pt-H_xMoO_3 and its activity toward methanol oxidation

A composite catalyst Nafion-Pt-HxMoO3 was prepared on a glassy carbon by cyclic voltammetry methods in sulfuric acid solution containing Na2MoO4,H2PtCl6 and Nafion,and its activity for the methanol oxidation was studied with Pt-HxMoO3 as comparison. It is found that the electrocatalytic activity and the stability of Pt-HxMoO3 are improved by the Nafion. The activity of Pt-HxMoO3 reaches its maximum when the content of Nafion in the preparation solution is 0.012%(mass fraction). In this case the oxidation peak current of methanol on Nafion-Pt-HxMoO3 is 1.76 times larger than that on Pt-HxMoO3 and keeps unchanged when the potential is set at 0.3 V(vs Hg-Hg2SO4) for 5 000 s in 1 mol/LCH3OH+0.5 mol/L H2SO4 solution. The results from energy dispersive spectroscopy show that the content of Nafion in the composite is 0.57%. The results from scanning electron spectroscopy show that the composite of Nafion-Pt-HxMoO has a gain size of about 90 nm and distributes more uniformly than Pt-HxMoO3.

Preparation of nano-platinum and its catalytic activity toward methanol oxidation and oxygen reduction

Nano-scale platinum catalysts were prepared on a glass carbon electrode by cyclic voltammetry. The surface morphology and active area of the catalysts,and their catalytic activity toward methanol oxidation and oxygen reduction were studied by SEM,linear and cyclic voltammetry. The result shows that the diameters of global Pt particles are affected by the scan rate of cyclic voltammetry:the faster the scan rate is,the smaller the diameters of Pt particles are. The size of the nano-scale platinum catalysts has different effects on their catalytic activity toward oxygen reduction and methanol oxidation:the catalyst with a size of 100 nm shows its best activity toward methanol oxidation,but the catalyst with a size of 65 nm shows its best activity toward oxygen reduction.

THE EFFECT OF MEDIUM ON ADSORPTION OF FREE ACID BY CROSSLINKED CHITOSAN RESIN

The adsorption of free acid of low concentration by crosslinked chitosan resin was followed by electrochemical experimental technique. The effect of acid concentration and the media on adsorption was discussed. The experimental results show that both the apparent rate constant and the interaction energy between the adsorbent and adsorbate are decreased while the concentration of hydrochloric acid is increased. In the adsorption system, the adsorption was effected by addition of organic solvent.

A STUDY ON THE ADSORPTION OF LOW CONCENTRATION FREE ALKALI BY SUBACID RESIN

The absorption of free alkali at low concentration by subacid resin was traced with electric conductance method, the effect of temperature on the adsorption, the activation energy of adsorption (Ea) and interaction energy (U) was studied. The result showed that, the process of low concentration alkali adsorption by subacid resin was in accordance with mechanism of monomolecular layer absorption, in addition, with the increasing of temperature, the interaction energy between adsorbate and sorbent increase, so did the surface adsorption rate (k), and linear correlation existed between interaction energy (U) and temperature (T).

Synthesis of Fulleropyrrolidines under Microwave Irradiation

In recent years, considerable efforts have been devoted to the development of systems in which C60 is covalently linked to an electron donor.[1] Studies[2] on intermolecular photoinduced electron transfer between C60 and triphenyl amine show that triphenyl amine is a good donor. It is envisaged that the use of donor segments consisting of either pyrrole/aniline may extend the lifetime of charge-separated state.[3] Since Gedye[4] demonstrated that many organic reactions can be conducted rapidly under microwave irradiation, here we have successfully synthesized five new fulleropyrrolidines containing triphenyl amine or thiophene dyads under microwave irradiation, which are different from traditional heating. The determination of structures of these fulleropyrrolidines is in progress. On the other hand, we have studied the geometry, electronic structures and frontier orbitals of these N-methyl-pyrrolo[3,4]C60 derivatives by using AM1semiempirical quantum calculation method. The results indicate that there exists strong intramolecular electron transfer in them.……

First Diels-Alder Addct of [60] Fullerene with a Piperidinoxanthate

In the search for intramolecular energy and electron transfer phenomena in [ 60 ] fullerene donor-containing molecules, some electron donor fragments have been covalently linked to the fullerene core. [1 ～4] Only in very fewcases has reliable evidence of thermal or photoinduced intramolecular electron transfer processes been reported. [5]With the aim of promoting an intramolecular electron transfer we sought to develop a novel type of 6-chlorophenazine derivative of [60]fullerene in which the 6-chloro-phenazine core is directly attached by two σ-bonds to the ball giving rise to a different and more rigid spatial orientation of the HOMO of the 6-chloro-phenazine addend with respect to the LUMO of [60]fullerene.……

Lithium intercalation mechanism for β-SnSb in Sn-Sb thin films

Based on the first-principles plane wave pseudo-potential method, the electronic structure and electrochemical performance of LixSn4Sb4 （x=2, 4, 6, and 8） and LixSn12-xSb4 （x=9, 10, 11, and 12） phases were calculated. A Sn-Sb thin film on a Cu foil was also prepared by radio frequency magnetron sputtering. The surface morphology, composition, and lithium intercalation/extraction behavior of the fabricated film were characterized by scanning electron microscopy （SEM）, X-ray diffraction （XRD） and cyclic voltammetry （CV）. Lithium atoms can easily insert into and extract out of the β-SnSb cell due to the low lithium intercalation formation energy. It is found that lithium atoms first occupy the interstitial sites, and then Sn atoms at the lattice positions are replaced by excessive lithium. The dissociative Sn atoms continue to produce different Li-Sn phases, which will affect the electrode stability and lead to the undesirable effect due to their large volume expansion ratio. The calculated lithium intercalation potential is stable at about 0.7 V, which is consistent with the experimental result.