巨化集团公司发展有机氟电解之浅见

介绍了有机氟电解的基本原理、电解方法的分类及产品种类,阐述了影响有机氟电解的因素,分析了巨化集团公司发展有机氟电解的必要性与优势,指出巨化公司发展有机氟电解将是跻身世界氟化工八强的重要举措之一。

Fabrication and characterization of tungsten-containing mesoporous silica for heterogeneous oxidative desulfurization

A series of functional,tungsten-containing mesoporous silica materials（W-SiO2） have been fabricated directly from an ionic liquid that contained imidazole and polyoxometalate,which acted as mesoporous template and metal source respectively.These materials were then characterized through X-ray diffraction（XRD）,transmission electron microscopy（TEM）,Raman spectroscopy,Fourier transform infrared spectra（FTIR）,diffuse reflectance spectra（DRS）,and N2 adsorption-desorption,which were found to contain tungsten species that were effectively dispersed throughout the structure.The as-prepared materials W-SiO2 were also found to possess a mesoporous structure.The pore diameters of the respective sample W-SiO2-20 determined from the TEM images ranged from 2 to 4 nm,which was close to the average pore size determined from the nitrogen desorption isotherm（2.9 nm）.The materials were evaluated as catalysts for the heterogeneous oxidative desulfurization of dibenzothiophene（DBT）,which is able to achieve deep desulfurization within 40 min under the optimal conditions（Catalyst（W-SiO2-20）= 0.01 g,temperature = 60℃,oxidant（H2O2）= 20 μL）.For the removal of different organic sulfur compounds within oil,the ability of the catalyst（W-SiO2-20） under the same conditions to remove sulfur compounds decreased in the order：4,6-dimethyldibenzothiophene Dibenzothiophene Benzothiophene 1-dodecanethiol.Additionally,they did not require organic solvents as an extractant in the heterogeneous oxidative desulfurization process.After seven separate catalytic cycles,the desulfurization efficiency was still as high as 90.3%.From the gas chromatography-mass spectrometer analysis,DBT was entirely oxidized to its corresponding sulfone DBTO2 after reaction.A mechanism for the heterogeneous desulfurization reaction was proposed.

Optimization of technological conditions for one-pot synthesis of (S)-α-cyano-3-phenoxybenzyl acetate in organic media

Optically active form of α-cyano-3-phenoxybenzyl (CPB) alcohol, building block of pyrethroid insecticides, was synthesized as its acetate by the combination of anion-exchange resin (D301)-catalyzed transcyanation between m-phenoxybenzaldehyde (m-PBA) and acetone cyanohydrin (AC), and lipase (from Alcaligenes sp.)-catalyzed enantioselective transesterification of the resulting cyanohydrin with vinyl acetate. Through optimizing technological conditions, the catalyzing efficiency was improved considerably compared to methods previously reported. Concentrations of CPB acetate were determined by gas chromatograph. The enantio excess (e.e.) values of CPB acetate were measured by NMR (nuclear magnetic resonance) method. Effects of solvents and temperatures on this reaction were studied. Cyclohexane was shown to be the best solvent among the three tested solvents. 55 °C was the optimal temperature for higher degree of conversion. External diffusion limitation was excluded by raising the rotational speed to 220 r/min. However, internal diffusion could not be ignored, since the catalyst (lipase) was an immobilized enzyme and its particle dimension was not made small enough. The reaction rate was substantially accelerated when the reactant (m-PBA) concentration was as high as 249 mmol/L, but decreased when the initial concentration of m-PBA reached to 277 mmol/L. It was also found that the catalyzing capability of recovered lipase was high enough to use several batches. Study of the mole ratio of AC to m-PBA showed that 2:1 was the best choice. The strategy of adding base catalyst D301 was found to be an important factor in improving the degree of conversion of the reaction from 20% to 80%. The highest degree of conversion of the reaction has reached up to 80%.

Al_(x)/HKUST-1 prepared by synthetic exchange as catalyst for reduction of NO by CO at low temperature

Al_(x)/HKUST-1(x=1/24,1/12,1/6,1/3),one of the bimetallic copper-based organic framework materials,was successfully prepared by the synthetic exchange method and characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),specific surface area(BET),thermogravimetric analysis(TG),infrared spectra(IR),X-ray photoelectron spectroscopy(XPS),and H_(2)-temperature programmed reduction(H_(2)-TPR).The findings indicated that Al_(x)/HKUST-1 maintained the octahedral morphology of its precursor(HKUST-1).The thermal stability and catalytic reduction ability of HKUST-1 skeleton were improved by doping aluminum(Al^(3+)).Al_(1/12)/HKUST-1 showed the best performance among all samples,with a nitric oxide(NO)conversion rate of 100%at 210℃(50℃lower than that of HKUST-1).The valence kind of Al,Cu,and O in Al_(1/12)/HKUST-1 did not change after the catalytic reaction,but the contents of Al,Cu,and O in different forms changed significantly.The catalytic process of the Al_(x)/HKUST-1 followed a Langmuir-Hinshelwood mechanism.

Finite element simulation of chip formation in peripheral milling mild carbon steel

A two-dimensional coupled thermo-mechanical model is used to simulate the progress of milling mild carbon steel with continuous chip formation. Deformation of the workpiece is treated as elastic-plastic with isotropic strain-hardening. An analysis of the properties of temperature-dependent materials is employed. The chip separation is achieved by the adaptive remeshing strategy module found in commercial finite element code Marc. In order to increase the computational efficiency and accuracy, we implement a customized subroutine into the Marc code to define local refinement at the tool tip. Measurements are taken of the shape of the chip, the temperature, stress, strain and strain-rate fields. The values of the cutting forces obtained from the simulations agree well with those obtained from the cutting experiments.

Cloning, Expression and Characterization of a Lipase Gene from Marine Bacterium Pseudoalteromonas lipolytica SCSIO 04301

Absract A lipase gene, 1ip1233, isolated from Pseudoalteromonas lipolytica SCSIO 04301, was cloned and expressed in E. coli. The enzyme comprised 810 amino acid residues with a deduced molecular weight of 80kDa. Lip1233 was grouped into the lipase family X because it contained a highly conserved motif GHSLG. The recombinant enzyme was purified with Ni-NTA affinity chro- matography. The optimal temperature and pH value of Lip1233 were 45 ℃ and 8.0, respectively. It retained more than 70% of origi- nal activity after being incubated in pH ranging from 6.0 to 9.5 for 30min. It was stable when the temperature was below 45℃, but was unstable when the temperature was above 55℃. Most metal ions tested had no significant effect on the activity of Lip1233. Lip1233 remained more than original activity in some organic solvents at the concentration of 30% （v/v）. It retained more than 30% activity after incubated in pure organic solvents for 12 h, while in hexane the activity was nearly 100%. Additionally, Lip 1233 exhib- ited typical halotolerant characteristic as it was active under 4M NaC1. Lip1233 powder could catalyze efficiently the synthesis of fructose esters in hexane at 400C. These characteristics demonstrated that Lip1233 is applicable to elaborate food processing and organic synthesis.

A general synthesis of transition metal oxides with assistance of organic amines and their electrocatalytic properties

Several transition metal oxides,including α-Fe2O3,Fe3O4,Co3O4,NiO,CuO and ZnO,were synthesized via an easily controlled hydrothermal method at assistance of organic amine(cyclohexylamine or triethylamine).The synthesized samples were identified and characterized by X-ray diffraction(XRD),Transmission Electron Microscopy(TEM),High-resolution Electron Microscopy(HR-TEM),Field Emission Scanning Electron Microscopy(FE-SEM),N2 adsorption/desorption measurement.The resultant metal oxides displayed various morphologies in shape.The as-prepared samples were used as electrocatalysts(CuO was excluded) modified on a glassy carbon electrode for p-nitrophenol reduction in a basic solution.Fe3O4 and Co3O4 samples showed higher catalytic activities.