Enthalpies of Absorption and Solubility of Carbon Dioxide in Aqueous Polyamine Solutions

The enthalpies of absorption and solubility at T=298.15 K of carbon dioxide in aqueous solutions of bis-(3-dimethylaminopropyl)amine (CAS RN: [6711-48-4]) are reported in this paper. It was observed that the saturation loading of the CO₂ is α=2.9 mol CO₂/mol TMBPA, which is close to the theoretical value, α⁰=3 mol CO₂/mol TMBPA. The molar heat of absorption of CO₂ is independent of the polyamine concentration of the solutions and the amount of CO₂ absorbed and was calculated to be Δ_abs H _m=–44 (±2) kJ mol^–1 CO₂. This revised version was published online in July 2006 with corrections to the Cover Date.     

负载1-丁基-3-甲基咪唑氯的固体炭磺酸催化水解纤维素

纤维素作为可再生资源,其催化水解得到的平台化合物对缓解能源压力具有重要的意义。 本文以生物质竹子为原料选择700 ℃预碳化、150 ℃磺化得到的固体炭磺酸为基体,负载1-丁基-3-甲基咪唑氯后得到离子液体功能化固体炭磺酸催化剂。 结果表明,催化剂最优条件下水解纤维素得到的总还原糖产率相对于固体炭磺酸提升了15.2%,循环使用后,依然表现出良好的催化性能。     

Experimental Research on NO2 Viscosity and Absorption for (1-Ethyl-3-methylimidazolium Trifluoroacetate + Triethanolamine) Binary Mixtures

The viscosity (9.34–405.92 mPa·s) and absorption capacity (0.4394–1.0562 g·g⁻¹) of (1-ethyl-3-methylidazolium trifluoroacetate + triethanolamine) binary blends atmospheric pressure in the temperature range of 303.15–343.15 K and at different mole fractions of [EMIM] [TFA] have been carried out. The molar fraction of [EMIM] [TFA] dependence of the viscosity and absorption capacity was demonstrated. The addition of a small amount of [EMIM] [TFA] into TEA led to rapidly decreased rates of binary blends’ viscosity and absorption capacity. However, the viscosity and absorption of binary blends did not decrease significantly when [EMIM] [TFA] was increased to a specific value. Compared with the molar fraction of the solution, the temperature had no obvious effect on viscosity and absorption capacity. By modeling and optimizing the ratio of viscosity and absorption capacity of ([EMIM] [TFA] + TEA), it is proven that when the mole fraction of [EMIM] [TFA] is 0.58, ([EMIM] [TFA] + TEA) has the best viscosity and absorption capacity at the same time. In addition, at 303.15 K, ([EMIM] [TFA] + TEA) was absorbed and desorbed six times, the absorption slightly decreased, and the desorption increased.     

Extraction of Uranium from Aqueous Solutions by Using Ionic Liquid and Supercritical Carbon Dioxide in Conjunction

Super powers! Uranium(VI) ions can be extracted from aqueous solutions into supercritical CO₂ (sc‐CO₂) via an ionic liquid phase that contained tri‐n‐butyl phosphate (TBP) as a complexing agent (see figure). This process has potential applications in the nuclear industry for removing actinides from nuclear waste.

     

Aggregation of Glycerol Induced by Carbon Nanotubes in Aqueous Solution and Its Influencing Factors

Carbon nanotubes(CNTs) have received wide application and investigation because of their unique electronic, chemical and mechanical properties. But the self-aggregation of CNTs limits their practical application and study. In order to disperse CNTs effectively, polymers, such as polyglycerol and its derivatives, are adopted as dispersants in view of their strong interaction with CNTs. In order to understand the interaction between CNTs and glycerol in water in detail, a series of simulations has been conducted to investigate the interaction between them and analyze the influences of CNTs diameter and temperature. All the analyses indicate that the glycerol molecules are prone to aggregate around CNTs with the addition of CNTs. This is mainly due to hydrophobic interaction. It is confirmed that this aggregation is influenced by CNTs diameter and the temperature to some degree. This work will establish the basis for the exploration of polyglycerol and its derivatives interacting with CNTs and provide an invaluable guide to seek for emergent dispersants for CNTs.     

Theoretical Analysis on Absorption of Carbon Dioxide (CO2) into Solutions of Phenyl Glycidyl Ether (PGE) Using Nonlinear Autoregressive Exogenous Neural Networks

In this paper, we analyzed the mass transfer model with chemical reactions during the absorption of carbon dioxide (CO2) into phenyl glycidyl ether (PGE) solution. The mathematical model of the phenomenon is governed by a coupled nonlinear differential equation that corresponds to the reaction kinetics and diffusion. The system of differential equations is subjected to Dirichlet boundary conditions and a mixed set of Neumann and Dirichlet boundary conditions. Further, to calculate the concentration of CO2, PGE, and the flux in terms of reaction rate constants, we adopt the supervised learning strategy of a nonlinear autoregressive exogenous (NARX) neural network model with two activation functions (Log-sigmoid and Hyperbolic tangent). The reference data set for the possible outcomes of different scenarios based on variations in normalized parameters (α1,α2,β1,β2,k) are obtained using the MATLAB solver “pdex4”. The dataset is further interpreted by the Levenberg–Marquardt (LM) backpropagation algorithm for validation, testing, and training. The results obtained by the NARX-LM algorithm are compared with the Adomian decomposition method and residual method. The rapid convergence of solutions, smooth implementation, computational complexity, absolute errors, and statistics of the mean square error further validate the design scheme’s worth and efficiency.     

1-丁腈-3-甲基咪唑双三氟甲基磺酸亚胺的性质

制备了功能化离子液体1-丁腈-3-甲基咪唑双三氟甲基磺酸亚胺。在T为283.15-353.15 K温度范围内,测定了该功能化离子液体的密度、动力粘度、电导率及折光率。讨论了亚甲基的增减对该类功能化离子液体的密度、动力粘度、电导率及折光率等性质的影响,并与传统咪唑类、吡啶类离子液体物理化学性质的变化趋势进行了对比。通过经验方程计算了该功能化离子液体的热膨胀系数、分子体积、标准摩尔熵及晶格能等热力学性质参数。讨论了Vogel-Fulcher-Tamman (VFT)方程和Arrhenius方程的适用性,得出VFT方程适用于该功能化离子液体,而Arrhenius方程并不适用。有关研究对新型离子液体的合成及其工业化的应用具有十分重要的意义。     

Stopped‐flow Spectrophotometric Study on the Reaction between Carbon Dioxide and [Co(NH3)4(H2O)2]3+ Ion in Aqueous Solution

Kinetics of the reaction of [tetraamminediaquacobalt(III)] perchlorate ion with carbon dioxide in aqueous solution was studied at various temperatures (5–25 °C), variable concentration of CO₂ (0.005M; 0.01M; 0.015M) and over the pH range 6.04–8.15 at a fixed ionic strength of solution (1 M NaClO₄). Investigations were carried out using stopped‐flow spectrophotometry in the range of 300 – 700 nm. The results enabled determination of the number of steps of the reaction studied. Based on the kinetic equations, rate constants were determined for each step. Finally, the mechanism of carbon dioxide uptake by [tetraamminediaquacobalt(III)] perchlorate ion was proposed and discussed.     

1-(1-Alkylsulfonic)-3-methylimidazolium chloride Brönsted acidic ionic liquid catalyzed Skraup synthesis of quinolines under microwave heating

1-(1-Alkylsulfonic)-3-methylimidazolium chloride Brönsted acidic ionic liquids are shown as excellent catalysts and reaction mediums for Skraup synthesis of quinolines under microwave conditions without the use of nitrobenzene as an oxidant and metal catalysts.     

Mutual solubilities of selected solvents and 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate

1-(2-Hydroxyethyl)-3-methylimidazolium tetrafluoroborate ([HYDEMIM][BF₄]) ionic liquid was characterised by infrared spectroscopy, nuclear magnetic resonance, ultraviolet-visible spectra and thermogravimetric analysis. Mutual mass fraction solubilities of the 12 selected solvents (ethanol, 1-propanol, 1-butanol, benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, dichloromethane, chloroform and carbon tetrachloride) and [HYDEMIM][BF₄] in the temperature range from 283.16 to 353.61?K were measured using a cloud-point method. Measured solubility value S was correlated as a function of temperature by a second-order polynomial.     

Separation of Ephedrines Using 1—Butyl—3—methylimidazolium—tetrafluoroborate Ionic Liquids as Eluent in High—performance Liquid Chromatography （HPLC）

A simple,effective HPLC method for separation of ephedrines was achieved by using 1-butyl-3-methylimidazolium-tetrafluoroborate ionic liquid solution (0.1% v/v) as eluent at pH3.0. The involved mechanism may be due to that the imidazolium cations can effectively shield the silanol groups of alkylsilica surface,thereby decreasing band tainling and increasing the separation efficiency.     

介孔聚离子液体的可控合成及在常压CO2环加成反应中应用

采用刚性的离子液体聚合单体双-（3-乙烯基-1-咪唑）亚甲基双溴盐（[C₁DVIM]Br）,以聚乙二醇（PEG）为溶剂,能够简单快捷制备出高比表面积的介孔聚离子液体.通过调节PEG的分子量大小,即可有效控制所得聚离子液体的孔结构.介孔聚离子液体由于具有典型的聚阳离子骨架、较高的比表面积以及丰富的卤素位,作为非金属多相催化剂在常压下氧化苯乙烯为底物的CO₂环加成反应中表现出优异的催化活性和良好的回收稳定性,循环使用5次后催化性能基本保持不变.此外,该催化材料还表现出良好的底物兼容性,可以有效转化很难反应的脂肪类环氧化合物.     

Optimization Studies of Porous Carbon Preparation from Oil Shale Using Response Surface Methodology and Its Application for Phenol Adsorption

This paper discusses the elaboration of adsorbents from oil shale. The experimental designs a response surface methodology(RSM), which has been applied to optimize the significant preparation factors, such as temperature, time, and the activating agent percentage. The results obtained from central composite design(CCD) revealed that the interaction between the factors was significant for the maximum quantity of adsorption(response). Planned results have shown that a maximum quantity of adsorption for methylene blue is 65 mg/g, which could be achieved with a temperature of 275℃ over 2 h and a percentage of the activating agent of 45%. The predicted values agreed with the experimental finding, with a determination coefficient(R²) of 0.96. The model has been validated by experiments after conditions optimization. The new material(RHO) was characterized by cation exchange capacity, zero charge pH, surface functions, X-ray fluorescence, specific surface area, and electron microscopy analysis. Phenol adsorption was determined using Langmuir, Freundlich and Temkin, which were used to describe the adsorption isotherms. The adsorption capacity of the material was about 263 mg/g, and the kinetic studies showed rapid adsorption.     

以镍为阴极由二氧化碳与芳香酮电合成α-羟基羧酸

室温下,在一室电解池中,以n-Bu4NBr-DMF作电解质、镍为阴极、铝为阳极,恒电流电解二氧化碳与芳香酮（苯乙酮、对二苯甲酮、6-甲氧基-2-萘乙酮、4-甲基苯乙酮和4-甲氧基苯乙酮）,可以得到相应的α-羟基羧酸（产率56%-90%）。实验结果显示,阴极材料、芳香族酮的结构以及电解条件（如电量、底物浓度、导电盐、溶剂和二氧化碳压力等）对目标产物的产率有很大影响;反应系统中质子剂（水）的存在将导致副产物频哪醇的生成。本文还根据循环伏安实验和合成实验结果简要地讨论了反应机理。     

Enthalpies of Solution of Organic Solutes in the Ionic Liquid 1-Methyl-3-ethyl-imidazolium Bis-(trifluoromethyl-sulfonyl) Amide

Enthalpies of solution of six organic solutes in the ionic liquid 1-methyl-3-ethyl-imidazolium bis-(trifluoromethyl-sulfonyl) amide have been measured at 25°C at low concentrations using titration calorimetry. Results at infinite dilution are compared with data obtained indirectly from activity coefficients at infinite dilution. Thermodynamic consistency has been confirmed within the experimental error of both methods.     

Vapour–liquid equilibrium measurements and modelling for the ternary system (water + 2-propanol + 1-butyl-3-methylimidazolium acetate)

Vapour–liquid equilibrium (VLE) data were measured for the ternary mixtures of water (1)?+?2-propanol (2)?+?1-butyl-3-methylimidazolium acetate ([bmim][OAc]) (3). Complete T, x and y data were obtained in a relatively wide range of ionic liquid (IL) mass fractions up to 0.8. The data were correlated by means of NRTL and eNRTL equations with satisfactory results. Using the eNRTL equation, the ternary VLE behaviour was also modelled through correlation of two data sets, in which the mole fraction of 2-propanol on IL-free basis is respectively at 0.1 and 0.98. In this way, the six data sets were reproduced satisfactorily, with root mean square deviations of 1.06?K for temperature and 0.0098 for vapour-phase mole fractions. Owing to the regular distribution of the experimental data, good agreement between experiment and calculation was graphically presented. Effect of the IL on the VLE behaviour of the volatile components was also illustrated.     

六水合三氯化铁在离子液体1－正丁基－3－甲基六氟磷酸翁盐中催化芳醛和乙酸酐合成1，1－二乙酸酯

在室温条件下，六水合三氯化铁在离子液体1－正丁基－3－甲基六氟磷酸翁盐 （[bmin]PF_6）中能催化一系列芳醛和乙酸酐反应，以85％－97％的产率生成相应 的1，1－二乙酸酯。