强缔合体系醋酸-水溶液密度和粘度测定及关联

测定了醋酸水二元体系常压下在298.15—363.15K时的密度和粘度数据,由密度数据计算出超额体积VE的值,并用Redlich Kister方程进行了回归;同时对粘度的数据也按超额性质的方法进行了处理,求出了不同温度不同组成下的ηE值。数据处理过程中发现,ηE/(x1x2)随组成没有变化,在不同温度下为一常数,根据这一特殊现象,建立了由纯物质的粘度数据来计算醋酸水体系在任意温度和组成下的粘度数据,并把所得粘度的计算值和实验值进行比较,120个数据点的平均相对误差为1.1%,结果比较满意。     

常压下二乙二醇单乙醚和水二元体系不同温度下的密度、黏度及过量性质

Densities and viscosities were measured as a function of composition for binary liquid mixture of diethylene glycol monoethyl ether [CH3CH2O(CH2)2O(CH2)2OH] + water from 293.15 to 333.15 K at atmospheric pressure, with a capillary pycnometer and Ubbelohde capillary viscometer respectively. From the experimental data, the excess molar volume VE, viscosity deviation η, and the excess energy of activation for viscous flow G*E were calculated. These data were correlated by the Redlich-Kister type equa-tions to obtain the coefficients and standard deviations. The results showed a strong molecular interaction between diethylene glycol monoethyl ether and water.     

N,N-二甲基甲酰胺+醇二元混合物的黏度测定与关联

在288.15~313.15 K和常压下,利用乌氏黏度计测定了N,N-二甲基甲酰胺（DMF）分别与乙醇、丙醇、乙二醇和1,2-丙二醇组成的二元系全浓度范围内的黏度,计算了过量黏度△η和过量流动活化自由能△G^*E。用Redlich-Kister方程对过量黏度进行了关联;用黏度模型如Frenkel方程,Grunberg-Nissan方程,Katti-Chaudhari方程和McAllister方程对实验黏度数据进行了关联和预测,并利用Eyring理论方法计算了流动活化自由能、活化焓和活化熵等热力学函数。结果表明,4个二元系的过量黏度和过量流动活化自由能均为负值,且都随温度降低而偏差增大。过量黏度最低值均发生在DMF摩尔分数约为0.3处。McAllister模型对黏度数据的关联结果最好,预测值与实验值的平均相对偏差最小。比较并分析了DMF与一元醇和二元醇之间分子相互作用的差异。。     

乙醇胺乳酸盐离子液体吸收SO2过程中的物理化学性质

测定了常压下乙醇胺乳酸盐-水二元混合体系纯组分及混合液在303.15～333.15 K温度内的密度和黏度, 并对实验数据进行拟合, 通过Jouyban-Acree模型将密度、黏度数据与温度和组成进行关联, 得到关联参数。实验还测定了不同水分含量下该体系饱和吸收SO₂后的密度、黏度。结果表明:该二元混合体系的密度随着温度以及水含量的增大而下降;在水分含量低时该体系的黏度随着温度以及含水量的增大而急剧下降;在水分质量分数超过60%时, 含水量对黏度变化的影响较小。在相同条件下饱和吸收SO₂后, 该体系的密度和黏度比吸收前的略有增大。另外, 分别由密度和黏度实验数据计算不同温度及组成下该二元体系的超额摩尔体积V^E和混合黏度变化Δη, 结果均为负值, 产生了负偏差, 说明离子液体与水之间较强的相互作用。     

Viscosities of binary liquid mixtures of cyclohexanone with alkanes,benzene, toluene and tetrachloromethane at 298.15 K

Viscosities for the binary liquid mixtures of cyclohexanone with n-hexane, n-heptane, 2, 2, 4-trimethylpentane, benzene, toluene and tetrachloromethane have been determined at 298.15 K. The deviation in viscosity from the ideal law is negative in all the systems except in the system, cyclohexanone with tetrachloromethane. In this system excess viscosity exhibits a positive deviation over the entire range of mole fraction. The results have been interpreted in terms of molecular interactions, and of difference in size and shape of components. The theoretical excess viscosities have been calculated from absolute reaction rate theory and free volume theory of flow by making use of the Bloomfield and Dewan relations. Theoretical excess viscosities are in qualitative agreement with experimental results for four out of the six systems examined.     

BuNENA/DMSO二元体系密度、黏度测定及关联

利用密度瓶和乌氏黏度计分别测定了25,40,50,70℃时BuNENA/DMSO二元体系的密度、黏度,并对黏度与温度、组成的关系进行了多项式回归,模型计算值平均相对误差在0.17%—1.53%。由密度数据计算出超额摩尔体积VmE,由黏度数据计算出不同温度、组成下的超额黏度Δη,其中VEm为正值,Δη为负值。对混合液在不同温度下的VmE与组成的关系用Redlich-Kister方程进行了关联,平均相对误差小于3%。     

Volumetric,ultrasonic and viscometric studies of binary liquid mixures of N-ethylaniline + chlorobenzene, + Bromobeneze, + 1, 2-dichlorobenzene + 1, 3-dichlorobenzene+1, 2, 4-trichlorobenzene at 303.15 and 308.15K

We measured densities (ρ), ultrasonic speeds (u) and viscosities (η) for binary binary mixtures of N-ethylaniline (N-EA) with chlorobenzene (CB), bromobenzene (BB), 1,2-dichlorobenzene (1,2-DCB), 1,3-dichlorobenzene (1,3-DCB), and 1,2,4-trichlorobenzene (1,2,4-TCB) and their pure liquids at 303.15 K and 308.15 K. These experimental data were used to calculate the excess volume (V ^E ), deviations in ultrasonic speeds (Δu), deviation in isentropic compressibility (Δ κ _s ), deviation in intermolecular free length (ΔL _f ), deviation in acoustic impedance (ΔZ), deviation in viscosity (Δη) and excess Gibbs free energy of activation of viscous flow (G* ^E ). The variations of these properties with composition of binary mixtures suggest loss of dipolar association, difference in size and shape of the component molecules, dipole-dipole interactions and hydrogen bonding between unlike molecules. The viscosity data were correlated with Grunberg and Nissan, Katti and Chaudhri, and Hind et al. equations and the results were compared with the experimental results. The excess parameters were fitted to the Redlich-Kister polynomial equation using multi parametric nonlinear regression analysis to derive the binary coefficients and to estimate the standard deviation.     

不同温度压力下纯水、醋酸+水、对二甲苯+醋酸+水黏度测定(英文)

The viscosities of pure water, the acetic acid + water binary system, and the p-xylene + acetic acid + water ternary system at different concentrations were determined with a rolling-ball viscometer at temperatures from 313.15 to 473.15 K and pressures from 0.10 to 3.20 MPa. The viscosity data were fitted by a correlation equation for the estimation of the mixture viscosities. The average absolute deviations (AAD) of the correlation for binary and ternary systems are 2.48% and 1.77%, respectively.     

乙酸乙酯-1,2-丙二醇二元系的密度、折射率和黏度

常压下测定了乙酸乙酯和1,2-丙二醇二元系在298.15～323.15 K下的密度、折射率和黏度,建立了混合液密度、黏度随组成和温度变化关系的方程。计算了过量摩尔体积V^E,折射率偏差Δn_D,黏度偏差Δη和过量流动活化自由能ΔG^*E。结果表明,过量摩尔体积低温时在全浓度范围内为负值,但随温度升高,在富酯区变为正值;而折射率偏差高温时在富醇区为微小正值,其他情况都是负值;黏度偏差和过量流动活化自由能显示了相同的变化关系,均为负值,且都随温度降低而偏差增大。     

3-庚3-庚酮+乙酸乙酯、3-庚酮+乙酸丁酯、3-庚酮+TBP、MIBK+TBP二元体系的过量摩尔体积和黏度

常压下测定了3-庚酮+乙酸乙酯、3-庚酮+乙酸丁酯、3-庚酮+磷酸三丁酯（TBP）、4-甲基-2-戊酮（MIBK）+磷酸三丁酯4个二元体系在293.15～318.15 K下的密度和黏度值,计算了二元体系的过量摩尔体积V^E和过量黏度Δη,并用Redlich-Kister方程对V^E和Δη进行了关联。混合溶剂的黏度数据采用Orrick-Erbar(O-E)基团贡献法进行了关联和预测,增加了O-E方法中的(-O)₃-P=O 基团贡献值。结果表明,O-E方法可根据现有的纯溶剂的黏度数据预测得到混合溶剂的黏度,平均误差小于15%。     

Viscosimetric studies on 2-methoxyethanol + 1,2-dimethoxyethane binary mixtures from −10 to 80°c

The kinematic viscosities (v) were measured for nine binary solvent mixtures of 2-methoxyethanol (ME) + 1,2-dimethoxyethane (DME) at nineteen temperatures ranging from ?10 to +80°C. The experimental data have been used to test some empirical equations of the type v = v(T), v = v(X₁) and v = v(T, X₁). The viscosities of all the mixtures increase from the values of pure DME to that of ME as the mole fraction of ME increases, and always yield a negative excess property (v^E) at all the investigated temperatures. Furthermore, thermodynamic parameters of viscous flow have been evaluated on the basis of the Eyring theory. The excess free energy of activation of viscous flow (ΔG^E) vs X₂ plot suggests the presence of a stable hetero-adduct, having ME : DME = 1 : 1 stoichiometric ratio.     

Excess volume and excess enthalpy of binary mixtures composed of 1,2-dichloropropane and 1-alkanol (C5-C8)

The excess molar volumes and excess molar enthalpies at T=298.15 K and atmospheric pressure for the binary systems {CH₃CHClCH₂Cl (1)+CH₃(CH₂) _n?1OH (2)} (n=5 to 8) have been determined over the whole range of composition from the density and heat flux measurements using a digital vibrating-tube densimeter and an isothermal calorimeter, respectively. The measured excess molar volumes of all binary mixtures showed positive symmetrical trend with values increasing with chain length of 1-alkanol. Similarly, excess enthalpy values of all binary mixtures showed skewed endothermic behavior with values increasing with chain length of 1-alkanol. The maxima of excess molar enthalpy values were observed around x₁=0.65 with excess enthalpy value ranging from 1,356.8 J/mol (1-pentanol) to 1,543.4 J/mol (1-octanol). The experimental results of both H _m ^E and V _m ^E are fitted to a modified version of Redlich-Kister equation using the Padé approximant to correlate the composition dependence. The experimental H _m ^E data were also fitted to three local-composition models (Wilson, NRTL, and UNIQUAC). The correlation of excess enthalpy data in these binary systems using UNIQUAC model provides the most appropriate results.     

STUDIES OF DYNAMIC VISCOSITY AND GIBBS ENERGY OF ACTIVATION OF BINARY AND TERNARY MIXTURES OF BENZYLCHLORIDE + NITROBENZENE + ISOBUTANOL FROM T = (288.15 TO 313.15) K

Densities and viscosities of ternary mixtures of benzylchloride + nitrobenzene + isobutanol and three corresponding binary mixtures (benzyl chloride + isobutanol, benzyl chloride + nitrobenzene, and nitrobenzene + isobutanol) have been determined over the whole concentration at a temperature range of 288.15 to 313.15 K under atmospheric pressure. Experimental data of resulting mixtures were used to calculate viscosity deviations, Δln η, and excess energies of activation of viscous flow, ΔG*^E, of the ternary system. The calculated data for binary mixtures have been fitted by the Redlich-Kister equation to determine the appropriate coefficients. In order to determine the coefficients of ternary data, Cibulka, Singh, and Nakata equations were used. The results have also provided a test for the Grunberg and Nissan equation for correlating the dynamic viscosities of binary and ternary mixtures with mole fractions.     

Ternary and constituent binary excess molar enthalpies of {1,2-dichloropropane + 2-pentanol + 3-pentanol} at T=298.15K

Excess molar enthalpies for the ternary system of {1,2-dichloropropane (1,2-DCP)+2-pentanol+3-pentanol} and their constituent binary mixtures {1,2-DCP+2-pentanol}, {1,2-DCP+3-pentanol}, and {2-pentanol+3-pentanol} have been measured over the whole range of composition using an isothermal micro-calorimeter with flow-mixing cell at T=298.15 K and atmospheric pressure. The experimental excess molar enthalpies of all the binaries and ternary mixture, including three pseudo-binary mixtures, are positive (endothermic effect) throughout the mole fraction range, except for the binary mixture {2-pentanol+3-pentanol} in which shows a small negative values over the entire composition range. The experimental binary H _{m, ij} ^E data were fitted to Redlich-Kister equation, and the Cibulka and the Morris equations were employed to correlate the ternary H _{m, 123} ^E data. Several empirical equations for predicting ternary excess enthalpies from constituent binary mixing data have been also examined and compared. The experimental results have been qualitatively discussed in terms of molecular interactions.     

环己酮-环己烷混合液密度和粘度的测定及关联

在常压下分别测定了环己酮与环己烷的混合液在293,15～343．15K下的密度和粘度,并由密度数据计算出超额体积V^E、由粘度数据计算出了不同温度和组成下的超额粘度△η,V^e为正值,△η为负值;同时对不同温度下的超额体积、超额粘度与组成的关系分别用Redlich—Kister方程进行了关联,最大标准偏差小于3％,说明此体系适合采用Redlich—Kister方程回归。混合溶液的粘度随温度的关系用Andrade公式进行了关联,各组成关联的相关系数接近于1。     

Properties of the n-methyl-2-pyrrolidinone-water system

Densities, excess volumes and heats of mixing, heat capacities, refractive indices and viscosities of various N-methyl-2-pyrrolidinone (NMP)-water mixtures are reported. The excess volumes and heat of mixing are negative and show their greatest deviations from ideality at 0.3 - 04 mole fraction NMP. The viscosity of the system passes through a maximum in the same region of solvent composition. These data indicate strong interaction between NMP and water and suggest the existence of transient polymeric species of the type — (NMP · 2H₂O)n?.     

Measurement of enthalpies of mixing in gaseous phase for the binary system carbon dioxide – hydrogen sulphide by an isothermal flow calorimeter

Enthalpies of mixing for the binary system carbon dioxide – hydrogen sulphide were measured by means of an isothermal flow calorimeter at temperatures of 293.15. 305.15 and 313.15 K. For the first isotherm, excess enthalpy measurements were made at pressures of 0.507, 1.013 and 1.419 MPa. For the last two isotherms, these measurements were performed at pressures of 0.507, 1.013 and 1.520 MPa. The experimental data were treated by the same techniques described for the systems previously studied (Barry et al., 1982a, 1982b, 1982c). Two types of binary interaction coefficients k_ij have been utilized for the prediction of experimental data from equations of state: coefficients k_ij independent of temperature and pressure, and k_ij's adjusted as function of temperature and pressure. A better prediction of the excess enthalpy experimental data was obtained from the latter series of binary interaction coefficients.     

Correlative and predictive models of viscosity study on Propiophenone with isomeric xylenes binary mixtures at <Emphasis Type="Italic">T</Emphasis>=(303.15 to 318.15) K

Densities and viscosities of binary mixtures of Propiophenone with o-xylene, m-xylene and p-xylene were measured over the entire composition range at T=(303.15 to 318.15) K and at 0.1Mpa atmospheric pressure. Experimental data used to calculate excess molar volume (V^E), deviation of viscosity (Δη), excess Gibb’s free energy (G^*E) activation of viscous flow for each binary system and the results were fitted to the Redlich-Kister polynomial equation to obtain the fitting coefficients and standard deviations. Viscosity values used to compute single adjustable interaction parameters from Grunberg and Nissan, Katti and Chaudhri, Hind et al., Tamara Kurata and Frenkel relations. Deviations in thermodynamic properties of the binary mixtures were discussed in terms of their molecular interactions between the components. Viscosity data correlated with the McAllister’s three body/four body models, Heric, Auslander, and Jouyban-Acree relations having two and three adjustable parameters for the studied binary mixtures. Viscosity relations like Kendall-Monroe, Bingham, Arrhenius, and Kendall were used to calculate and compare the standard deviation percentage, (σ %), between the experimental and calculated viscosity data. The studied systems showed specific intermolecular interactions and the percentage deviations were in good agreement with the experimental values. Obtained results are useful in various chemical and industrial processes.     

Implication of the microstructure of binary Cu/ZnO catalysts for their catalytic activity in methanol synthesis

Binary Cu/ZnO catalysts with varying molar ratios (90/10 through 10/90) were studied under methanol synthesis conditions at 493 K and at atmospheric pressure. The methanol synthesis activity of the catalysts was correlated to their specific Cu surface area (N₂O reactive frontal chromatography, N₂O RFC) after reduction in 2 vol% H₂ at 513 K. Activity data were supplemented with a detailed analysis of the microstructure, i.e., crystallite size and strain of the reduced Cu and the ZnO phases after reduction using X-ray diffraction line profile analysis. The estimated copper surface area based on a spherical shape of the copper crystallites is in good agreement with data determined by N₂O RFC. A positive correlation of the turnover frequency for methanol production with the observed microstrain of copper in the Cu/ZnO system was found. The results indicate a mutual structural interaction of both components (copper and zinc oxide) in the sense that strained copper particles are stabilized by the unstrained state of the zinc oxide microcrystallites. The observed structural deformation of ZnO in samples with higher Cu loading can originate, for instance, from epitaxial bonding of the oxide lattice to the copper metal, insufficient reduction or residual carbonate due to incomplete thermal decomposition during reduction. Additional EXAFS measurements at the Cu K and the Zn K edge show that about 5% ZnO are dissolved in the CuO matrix of the calcined precursors. Furthermore, it is shown that the microstructural changes (e.g., size and strain) of copper can be traced back to the phase composition of the corresponding hydroxycarbonate precursors.     

Bubble point pressures and densities of hexamethyldisiloxane–carbon dioxide binary mixture using a constant volume view cell

The phase behavior of hexamethyldisiloxane (HMDS)–carbon dioxide (CO₂) binary mixture was investigated using a constant volume view cell. The accuracy of the measurement technique was inspected against the bubble point pressure data in the literature for ethanol (C₂H₅OH)–carbon dioxide (CO₂) binary mixture. The bubble point pressures for C₂H₅OH–CO₂ agreed well with the literature values. The bubble point pressures of HMDS–CO₂ binary mixture were determined at five different temperatures (T = 298.2 K, 308.2 K, 313.2 K, 323.2 K, 333.2 K) and at various compositions. The bubble point pressures increased with increasing temperature and CO₂ mole fraction in the binary mixture. The phase behavior of the binary mixture was modeled using the Peng–Robinson Stryjek–Vera equation of state (PRSVEoS). The binary interaction parameters were regressed from experimental bubble point pressures at each temperature and were found to exhibit a linear dependency on temperature. The HMDS–CO₂ binary mixture was also found to exhibit Type II phase behavior. Additionally, P–T–ρ measurements for the same binary system were conducted and excess molar volumes were calculated.