2,2,6,6-四甲基-4-氨基哌啶的精馏提纯

通过CSGC-PRV方程计算得到哌啶胺和哌啶醇的饱和蒸汽压数据并拟合出安托尼常数,采用COSMO-SAC方法计算哌啶胺-哌啶醇体系中各组分的活度系数,通过泡点计算得到哌啶胺-哌啶醇二元体系汽液平衡关系。根据计算结果,进行了哌啶胺间歇精馏提纯试验,获得了纯度大于99.00%(质量分数)的哌啶胺。     

A chromatographic study of the diffusion of N2,CH4 and binary CH4-N2 mixtures in 4A molecular sieve

The kinetics and equilibrium of sorption of CH₄, N₂ and binary CH₄–N₂ mixtures in 4A molecular sieve have been studied by a chromatographic method. The equilibrium isotherms and zeolitic diffusivities, determined with a helium carrier, show good agreement with previous gravimetric data. Counter-diffusion in the binary adsorbed phase was investigated using a mixed carrier gas and following the response to a small step change from a previously established equilibrium position. The dynamic response curves for the binary system could be satisfactorily interpreted on the assumption that both components in the mixture diffuse independently with the same intrinsic mobilities as for the single component systems.     

AP-P4/SDBS二元体系在石英砂上的吸附特性

针对AP-P4/SDBS聚表二元体系,选用不同浓度配方的聚表体系,在石英砂上展开静态吸附和动态滞留实验,研究聚表体系中各组分的吸附规律,考察了浓度、温度、矿化度对组分的吸附影响。结果表明,聚表二元体系中各组分在石英砂上的吸附符合Langmuir吸附模式,其中,SDBS表现为双分子层吸附、AP-P4表现为单分子层吸附特质。AP-P4与SDBS存在竞争吸附关系,SDBS的吸附量是AP-P4的20多倍。温度和矿化度升高,SDBS的吸附量增大。聚表二元体系中SDBS的动态滞留量小于其静态吸附量,而AP-P4的动态滞留量大于其静态吸附量。     

CO_2,CH_4在全硅MFI型沸石中吸附的分子模拟

采用巨正则蒙特卡洛(GCMC)分子模拟方法研究了CO2,CH4分子在全硅MFI型沸石中的吸附行为,计算得到了纯组分和两组分的混合物在不同温度时的吸附等温线;分析了全硅MFI型沸石对混合组分的选择性吸附;模拟还得到了CO2,CH4分子在全硅MFI型沸石中的吸附位。     

An investigation of the phase transformations in a CaSO4/(NH4)2SO4/H2O system,directed at the preparation of a fine dispersed purified phosphogypsum

The process of recrystallization of apatite phosphogypsum (PHG) in a solution ammonium sulphate (AS) with the subsequent decomposition of the binary salt was investigated and the resulting highly dispersed products with a low P₂O₅ content have been discussed. The following effects were examined: (NH₄)₂SO₄ concentration, the quantity of ammonium sulphate, the reaction temperature of phosphogypsum with (NH₄)₂SO₄ solution, the time of treatment of phosphogypsum with (NH₄)₂SO₄ solution and the decomposition of the binary salt, as well as the liquid/solid ratio for the binary salts, Based on the results of the chemical and X-ray analysis, it was established that, depending on the technological conditions of the process of recrystallization, binary salts of (NH₄)₂SO₄·CaSO₄·H₂O and of (NH₄)₂SO₄·CaSO₄·H₂O and of (NH₄)₂SO₄·5 CaSO₄·H₂O were formed. As a result of the investigations carried out, a product with a low P₂O₅ content, suitable for direct processing to secondary products has been prepared.     

Separation of Close-Boiling Mixtures of 4-Methoxyphenol/Catechol with tert-Butanol

ABSTRACT

Solid-liquid equilibrium (SLE) behavior was observed for close-boiling mixtures of 4-methoxyphenol and catechol with tert-butanol. The experimental liquidus lines of binary systems showed that intermolecular complex compounds were formed in both tert-butanol/4-methoxyphenol and tert-butanol/catechol, implying that tert-butanol is a potential medium to serve as an adductive agent for separation of 4-methoxyphenol and catechol. A ternary SLE phase diagram for the tert-butanol/4-methoxyphenol/catechol system was thus prepared and, based on the diagram, the feasibility of such separation processes was discussed. Furthermore, the binary SLE data were correlated with the ideal-chemical model. The model with the determined parameters from binary mixtures was then applied to predict the equilibrium temperatures for the ternary system.     

水、4-甲基-2-戊酮、4-甲基-2-戊醇三元体系汽液平衡和液液平衡的研究

用改进的双循环平衡釜测定了水、4-甲基-2-戊酮、4-甲基-2戊醇三元体系常压下的汽液平衡,将实测值与由二元体系以NRTL模型推算的三元体系汽液平衡计算值进行了比较,结果比较吻合.提出了一种改进的平衡釜用以测定常压、沸点下该体系的液液平衡.     

Graft copolymerization of acrylonitrile and its binary mixture with 4-vinyl pyridine onto isotactic polypropylene powder by preirradiation method

Graft copolymerization of acrylonitrile (AN) and its binary mixture with 4-vinyl pyridine (4-VP) onto isotactic polypropylene powder in aqueous medium, using γ-rays as an initiator, was studied. Optimum conditions for affording maximum percentage of grafting were evaluated. Rate of grafting (Rg) of AN and binary mixture (4-VP + AN) was determined as a function of total initial monomer concentrations. The graft copolymers were characterized by IR spectroscopy and thermogravimetric analysis. © 1995 John Wiley & Sons, Inc.     

An exploration of 3-methoxypropionitrile chemical sensor based on layered hexagonal NiCo2O4 nanoplates as electrode material

Binary metal oxide, nickel-cobalt oxide (NiCo₂O₄), was hydrothermally synthesized for the successful utilization as electrochemical electrode in chemical sensor. Benefited from the large surface area, binary NiCo₂O₄ stacked hexagonal nanoplates (HNPs) based electrode was utilized for the electrochemical sensing application towards teratogenic chemical i.e. 3-methoxypropionitrile (3-MPN). The sensing results displayed a reproducible sensitivity of ~605 μAμM^?1cm^?2, detection limit of ~11.8 μM with the correlation coefficient (R) of ~0.99502 and good linearity from ~10 μM to ~100 μM. Stability and repeatability of binary NiCo₂O₄ stacked HNPs based electrode was investigated with satisfactory results. Our synthesized binary NiCo₂O₄ stacked HNPs based electrode is promising for sensor applications and thus, enlightens the possibility of synthesizing other binary oxide materials.     

4-羟基苯甲醛及其溴代物固液平衡数据测定与关联

引　言香兰素 (vanillin) ,即 3 甲氧基 4 羟基苯甲醛 ,是一种广谱型香料 ,广泛应用于食品、化妆品等行业 ,需求日益增长 .近年来提出的以 4 羟基苯甲醛 (以下简称对醛或Ⅰ )为原料 ,经溴化、甲氧基化人工合成香兰素的新工艺[1～ 3 ] ,越来越受到人们的重视 .溴化反应是该工     

Phase transformation in CeO2–Co3O4 binary oxide under reduction and calcination pretreatments

The CeO₂–Co₃O₄ binary oxide was prepared by impregnation of the high surface area Co₃O₄ support (S.A. = 100m² g⁻¹) with cerium nitrate (20 wt% cerium loading on Co₃O₄). Pretreatment of CeO₂–Co₃O₄ binary oxide was divided both methods: reduction (under 200 and 400 °C, assigned as CeO₂–Co₃O₄–R200 and CeO₂–Co₃O₄–R400 and calcination (under 350 and 550 °C, assigned as CeO₂–Co₃O₄–C350 and CeO₂–Co₃O₄–C550). The binary oxides were investigated by means of X-ray diffraction (XRD), nitrogen adsorption at −196 °C, infrared (IR), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS) and temperature programmed reduction (TPR). The results showed that the binary oxides pretreatment under low-temperatures possessed larger surface area. The cobalt phase of binary oxides also was transferred upon the treating temperature, i.e., the CeO₂–Co₃O₄–R200 binary oxide exhibited higher surface area (S.A. = 109m² g⁻¹) and the main phase was CeO₂,Co₃O₄ and CoO. While, the CeO₂–Co₃O₄–R400 binary oxide exhibited lower surface area (S.A. = 40m² g⁻¹) and the main phase was CeO₂, CoO and Co. Apparently, the optimized pretreatment of CeO₂–Co₃O₄ binary oxide can control both the phases and surface area.     

Isotherms and thermodynamics studies for binary adsorption of methane and ethane on 4A molecular sieve zeolite

The temperature dependency of adsorption behavior for binary mixture of methane and ethane on 4A zeolite was investigated. The volumetric method has been adopted for determination of adsorption isotherm data in the temperature range 303–323 K and pressure up to 225 kPa. Extended Langmuir, modified extended Langmuir, and extended Freundlich isotherms were applied for prediction of binary adsorption data using pure component adsorption data. The data were also simulated by IAST model which showed the best correlation of experimental binary adsorption data along with extended Freundlich isotherm. The selectivity of 4A zeolite to adsorb gases was also studied. The result of this study showed that an increases in temperature increases selectivity for ethane to methane. The heats of adsorption for methane and ethane were also determined and found to be ?23.89 and ?36.78 kJ/mol, respectively, which indicate the exothermic and physisorption natures of adsorption.     

Facile synthesis of oxazolidinones catalyzed by n-Bu4NBr3/n-Bu4NBr directly from olefins,chloramine-T and carbon dioxide

A binary catalyst system composed of n-Bu₄NBr₃/n-Bu₄NBr was developed for facile synthesis of 5-substituted 2-oxazolidinones with perfect regioselectivity in a single operation directly from olefins, chloramine-T and CO₂. The choice of efficient binary catalysts for two steps, i.e. aziridination and cycloaddition, and the optimization of reaction condition are keys to the one-pot synthesis of 5-substituted 2-oxazolidinones. A possible mechanism for the present one-pot synthesis of oxazolidinones was also proposed.     

CF_4和惰性气体混合物的输运性质的计算

The present work is concerned with determining the viscosity, diffusion, thermal diffusion factor and thermal conductivity of five equimolar binary gas mixtures including: CF_4-He, CF_4-Ne, CF_4-Ar, CF_4-Kr, CF_4-Xe from the principle of corresponding states of viscosity by the inversion technique. The Lennard-Jones (12-6) model potential is used as the initial model potential. The calculated interaction potential energies obtained from the inversion procedure is employed to reproduce the viscosities, diffusions, thermal diffusion factors, and thermal conductivities. The accuracies of the calculated viscosity and diffusion coefficients were 1% and 4%, respectively.     

Glass Formation and Vibrational Spectra of Glasses in the SrSO4–KPO3–Na2B4O7 System

The glass formation region in the SrSO₄–Na₂B₄O₇–KPO₃ system is determined for the first time. This region occupies 31.8% of the concentration triangle predominantly in the polyphosphate region. The boundary of the glass formation lies along the binary line connecting the sodium tetraborate and potassium metaphosphate regions and reaches compositions with 40 mol % SrSO₄. Along the line connecting the potassium phosphate and sodium tetraborate regions, the glass formation at 10 mol % SrSO₄ is bounded by the 0.1SrSO₄–xNa₂B₄O₇–(0.9 – x)KPO₃ join (the Na₂B₄O₇–KPO₃ binary join is vitrified completely). From analyzing the IR and Raman spectra, it is assumed that the structure of the glasses under investigation is formed by lattices of two types, namely, the sulfate phosphate and borate lattices.     

Adsorption and separation of CO2/N2 and CO2/CH4 by 13X zeolite

Accumulation of greenhouse gases in the atmosphere is responsible for increased global warming of our planet. The increasing concentration of carbon dioxide mainly from flue gas, automobile and landfill gas (LFG) emissions are major contributors to this problem. In this work, CO₂, CH₄ and N₂ adsorption was studied on Ceca 13X zeolite by determining pure and binary mixture isotherms using a constant volume method and a concentration pulse chromatographic technique at 40 and 100°C. The experimental data were then compared to the predicted binary behaviour by extended Langmuir model. Results showed that the extended Langmuir theoretical adsorption model can only be applied as an approximation to predict the experimental binary behaviour for the systems studied. Equilibrium phase diagrams were obtained from the experimental binary isotherms. For these systems, the integral thermodynamic consistency tests were also conducted. It was found that Ceca 13X exhibits large CO₂/CH₄ and CO₂/N₂ selectivity and could find application in landfill gas purification, CO₂ removal from natural gas and CO₂ removal from ambient air or flue gas streams. © 2011 Canadian Society for Chemical Engineering     

Phase Diagram of the Li4GeS4–Li3PS4 Quasi‐Binary System Containing the Superionic Conductor Li10GeP2S12

A phase diagram is constructed for the quasi‐binary Li₄GeS₄–Li₃PS₄ system containing the lithium superionic conductor Li₁₀GeP₂S₁₂ (LGPS), having an LGPS‐type structure, and the β‐Li₃PS₄‐type phase, having a thio‐LISICON structure. The LGPS and thio‐LISICON intermediate compounds are found to exhibit solid solution ranges and show incongruent melting at 650°C and 560°C, respectively. The end‐member Li₄GeS₄ has a compositional range of 0 < k < 0.3 in [(1?k) Li₄GeS₄ + k Li₃PS₄], while the other end‐member γ‐Li₃PS₄ has no solid solution range. The crystal structures appearing in the binary systems are the α‐, β‐, and γ‐type Li₃PS₄ structures and the LGPS‐type structure, and these are formed by PS₄ tetrahedra with different arrangements in each structure. The phase and structural relationships between the compounds appearing in the Li₄GeS₄–Li₃PS₄ system are thus clarified.     

N_2-CH_4-CO_2体系近临界区域高压流体相平衡研究

<正>1引言为开发出有经济价值的高纯度CO。气,合适的方法是用吸附分离法脱除CH。和乙、Ce烃,但风难以用吸附法脱去,肉此必须在吸附装置前加一提纯设备以除去比及大部分CH;。考虑能量利用的合理性,希望这一设备能在常温下操作,因而风－CH。－CO。体系在常温下的高压流体相平衡数据就成为提纯装置的设计基础。     

Decreasing miscibility with greater heterogeneity in ternary polymer blend: poly(cyclohexyl methacrylate), poly(α‐methyl styrene) and poly(4‐methyl styrene)

A ternary blend system comprising poly(cyclohexyl methacrylate) (PCHMA), poly(α‐methyl styrene) (PαMS) and poly(4‐methyl styrene) (P4MS) was investigated by thermal analysis, optical and scanning electron microscopy. Ternary phase behaviour was compared with the behaviour for the three constituent binary pairs. This study showed that the ternary blends of PCHMA/PαMS/P4MS in most compositions were miscible, with an apparent glass transition temperature (T_g) and distinct cloud‐point transitions, which were located at lower temperatures than their binary counterparts. However, in a closed‐loop range of compositions roughly near the centre of the triangular phase diagram, some ternary blends displayed phase separation with heterogeneity domains of about 1 µm. Therefore, it is properly concluded that ternary PCHMA/PαMS/P4M is partially miscible with a small closed‐loop immisciblity range, even though all the constituent binary pairs are fully miscible. Thermodynamic backgrounds leading to decreased miscibility and greater heterogeneity in a ternary polymer system in comparison with the binary counterparts are discussed. © 2003 Society of Chemical Industry     

磁性能优化纳米Fe3O4合成工艺

通过化学共沉淀法制备了纳米Fe3O4粉体,研究了反应物配比和反应温度对磁性粒子的物相以及磁性能的影响,优化了合成工艺。通过对二元参数的选择和严格控制,可以制备出磁化率高、粒径分布相对较好的球形磁性颗粒,干燥后获得纳米磁性粉体。