溴代烷基咪唑类离子液体水溶液二元体系的物化性质研究

测定了溴代烷基咪唑类离子液体水溶液[C_n mim]Br(n=2,4,6,8)+H_2O二元体系在288.15～308.15K下的密度和折光率,同时计算了[C_n mim]Br(n=4,6,8)+H_2O二元体系的过量摩尔体积(V_m~E)和折光率偏差(Δn_D),从微观角度分析讨论了二元体系中各粒子之间的相互作用。结果表明,随着离子液体质量分数的增大,二元体系的密度和折光率逐渐增大;随着离子液体摩尔分数的增大,过量摩尔体积逐渐减小;随着离子液体烷基侧链的增长,二元体系的密度和折光率逐渐减小、过量摩尔体积逐渐增大;随着温度的升高,二元体系的密度和折光率略微减小、过量摩尔体积和折光率偏差缓慢增大;在288.15K下,二元体系的过量摩尔体积均为负值,且随着温度的升高逐渐增大,表明体系中各粒子之间有较强的相互作用力,且相互作用随着温度的升高而减弱。     

咪唑离子液体氯化物水溶液的密度、折光率和体积性质

常压下,测定了咪唑离子液体氯化物([C_2mim]Cl、[C_4mim]Cl、[C_6mim]Cl、[C_8mim]Cl)与水的二元混合溶液在288.15K、298.15K、308.15K下的密度和折光率,计算获得了过量摩尔体积和折光率偏差,并用Redlich-Kister方程对衍生性质数据进行拟合,通过过量摩尔体积研究了二元混合溶液中离子液体与水分子之间的相互作用,同时采用多项式方程对二元混合溶液的密度及折光率随组成的变化进行了拟合。结果表明,二元混合溶液的密度和折光率随离子液体质量分数的增加而增大,随离子液体阳离子烷基链的增长、温度的升高而减小;二元混合溶液的过量摩尔体积为负值而折光率偏差为正值;离子液体与水分子之间具有较强的相互作用。     

1,2-丙二醇+丁醇/戊醇/己醇二元系的过量体积和黏度

常压下测定了1,2-丙二醇分别与丁醇、戊醇和己醇组成的二元系在293.15~318.15 K下的密度和黏度,建立了混合液密度和黏度随温度和组成变化的方程。计算了过量摩尔体积VE,黏度偏差Δη和过量流动活化自由能ΔG*E。结果表明,三个二元系的过量摩尔体积在全浓度范围内均为正值,随温度升高,偏差增大,但发生最大偏差时的溶液组成不同;过量摩尔体积值按丁醇-戊醇-己醇顺序逐渐增大;黏度偏差和过量流动活化自由能三个体系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。利用Redlich-Kister方程对过量性质进行了关联。分析和讨论了分子间相互作用。     

乙酸乙酯/四氯化碳二元混合体系的体积性质

常压下测定了乙酸乙酯与四氯化碳二元体系在288.15-323.15 K内全摩尔分数范围的密度,分别建立了该二元体系密度与组成和温度的计算方程.在此基础上,计算了该二元体系的超额摩尔体积,结果表明:该二元体系的超额摩尔体积在所测定温度和全摩尔分数范围内均呈正偏差,且均随温度的升高而偏差增大,并利用Redlich-Kist...     

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。     

甲酰胺+乙醇/丙醇/异丙醇/乙酸乙酯二元混合物的体积及黏度性质

为理解含甲酰胺二元溶液的超额性质变化及分子间相互作用,常压下测定了甲酰胺(FA)分别与乙醇、丙醇、异丙醇和乙酸乙酯组成的二元系在293.15~318.15 K的密度和黏度,计算了超额摩尔体积(VE)和黏度偏差(Δη)。采用半经验的黏度方程对实验黏度数据进行了关联和预测,并基于Eyring绝对速率理论方法计算了黏滞性活化参数。结果表明,四个二元系的超额摩尔体积均为负值,且都随温度升高而偏差增大。FA-乙醇和FA-乙酸乙酯两个体系的黏度偏差为负值,且随温度降低而偏差增大。FA-丙醇和FA-异丙醇两个体系的黏度偏差随FA组分增加呈‘S’形变化,在甲酰胺低浓度区由负值变为正值,也均随温度降低而偏差增大。Mc Allister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。黏滞性活化参数说明混合过程中焓驱动起主导作用。     

N-苯基马来酰亚胺在有机溶剂中密度和黏度测定及关联

N-苯基马来酰亚胺作为优良的改性单体,广泛应用于树脂的耐热改性、高分子材料的交联剂等,然而N-苯基马来酰亚胺及其二元混合体系的密度与黏度却鲜有报道。利用密度瓶和乌氏黏度计分别测定了100 kPa下N-苯基马来酰亚胺在乙醇、丙酮、乙酸乙酯3个体系293.15—318.15 K等6个温度时的密度与黏度。同时根据测定的密度数据计算出了N-苯基马来酰亚胺在3个体系中的表观摩尔体积。结果表明:测定范围内,溶液的密度与黏度均随着温度的升高而降低,随着N-苯基马来酰亚胺质量摩尔浓度的增大而增大;而表观摩尔体积随着温度的升高而升高,随着N-苯基马来酰亚胺质量摩尔浓度的增大而降低。用VTF方程对密度、黏度数据进行关联,分别拟合得到2个关联方程,标准偏差小于1.6%。     

乙酸乙酯-异丙醇二元系的黏度行为和表面性质

常压下测定了乙酸乙酯和异丙醇二元系在298.15～323.15 K下的黏度和表面张力,计算了黏度偏差、过量流动活化自由能和表面张力偏差,采用Redlich-Kister方程进行了关联。结果表明,黏度偏差、过量流动活化自由能和表面张力偏差均为负值,且显示了相同的变化趋势,随温度降低而偏差增大。利用表面张力数据进一步考察了混合液表面熵和表面焓,并基于扩展的Langmuir模型,计算了异丙醇的疏液性β及其表面组成。β值表明异丙醇对表面有更大的亲和力,其表面组成始终高于在溶液本体中的组成。     

2-甲基-1,3-丙二醇水溶液密度和粘度的测定及关联

常压下采用密度瓶测定了纯液体2-甲基-1,3-丙二醇(MPO)及不同浓度的MPO 水二元体系在298.15~367.15K范围的密度;用乌氏粘度计测定了纯液体MPO及该二元体系在相应温度下的粘度.结果表明:MPO及其水溶液的密度和粘度均随温度升高而减小,密度呈线性衰减,粘度呈指数衰减;一定温度下MPO 水二元体系的密度随浓度变化大约在70%处出现了一极大值. 同时分别由密度和粘度实验数据计算了不同温度及组成下该二元体系的超额摩尔体积V E和混合粘度变化△η,结果V E和△η均为负值, 说明产生了负偏差.并由实验数据拟合出Grunberg-Nissan模型中的MPO-水体系的二元交互参数△Gij,它与温度和组成均有关.     

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。     

Effect of Temperature on the Physico-Chemical Properties of a Room Temperature Ionic Liquid (1-Methyl-3-pentylimidazolium Hexafluorophosphate) with Polyethylene Glycol Oligomer

A systematic study of the effect of composition on the thermo-physical properties of the binary mixtures of 1-methyl-3-pentyl imidazolium hexafluorophosphate [MPI][PF(6)] with poly(ethylene glycol) (PEG) [M(w) = 400] is presented. The excess molar volume, refractive index deviation, viscosity deviation, and surface tension deviation values were calculated from these experimental density, ρ, refractive index, n, viscosity, η, and surface tension, γ, over the whole concentration range, respectively. The excess molar volumes are negative and continue to become increasingly negative with increasing temperature; whereas the viscosity and surface tension deviation are negative and become less negative with increasing temperature. The surface thermodynamic functions, such as surface entropy, enthalpy, as well as standard molar entropy, Parachor, and molar enthalpy of vaporization for pure ionic liquid, have been derived from the temperature dependence of the surface tension values.     

Excess molar volumes and refractive indices of mixtures formed by acetates with sunflower oil at different temperatures

The aim of this work is to measure the densities and refractive indices of mixtures formed of acetates (ethyl, vinyl, propyl, isopropyl, and butyl acetate) with sunflower oil. From these measurements, excess molar volumes and variations of the refractive index of the mixtures have been calculated. The properties were measured at temperatures varying from 288.15 to 298.15 K. The excess molar volumes and variations of refractive index data were correlated vs. composition with Redlich-Kister polynomials. Densities of the mixtures were predicted by the Rackett and modified Rackett equations. Refractive indices of the mixtures were predicted by several mixing rules and compared with experimental values. In all cases, SD between predicted and experimental data were less than 5%.     

二元混合物环丁酚和对二甲苯、乙苯在温度范围为303.15-353.15K下的密度、黏度及其相关性质

Densities and viscosities of the binary systems of sulfolane ethylbenzene, sulfolane p-xylene have been experimentally determined in temperature interval 303.15-353.15 K and at atmospheric pressure for the whole composition range. The excess molar volumes and viscosity deviations were computed. The computed quantities have been fitted to Redlich-Kister equation. Excess molar volumes and viscosity deviation show a systematic change with increasing temperature. Two mixtures exhibit negative excess volumes with a minimum which occurs approximately at x = 0.5. The effect of the size, shape and interaction of components on excess molar volumes and viscosity deviations is discussed.     

二元混合物环丁酚和对二甲苯、乙苯在温度范围为303.15—353.15K下的密度、黏度及其相关性质

Densities and viscosities of the binary systems of sulfolane ＋ ethylbenzene, sulfolane ＋ p-xylene have been experimentally determined in temperature interval 303.15—353.15 K and at atmospheric pressure for the whole composition range. The excess molar volumes and viscosity deviations were computed. The computed quantities have been fitted to Redlich-Kister equation. Excess molar volumes and viscosity deviation show a systematic change with increasing temperature. Two mixtures exhibit negative excess volumes with a minimum which occurs approximately at χ = 0.5. The effect of the size, shape and interaction of components on excess molar volumes and viscosity deviations is discussed.     

Physicochemical properties of glycine-based ionic liquid [QuatGly-OEt][EtOSO(3)] (2-Ethoxy-1-ethyl-1,1-dimethyl-2-oxoethanaminium ethyl sulfate) and its binary mixtures with poly(ethylene glycol) (M(w) = 200) at various temperatures

This work includes specific basic characterization of synthesized glycine-based Ionic Liquid (IL) [QuatGly-OEt][EtOSO(3)] by NMR, elementary analysis and water content. Thermophysical properties such as density, ρ, viscosity, η, refractive index, n, and conductivity, κ, for the binary mixture of [QuatGly-OEt][EtOSO(3)] with poly(ethylene glycol) (PEG) [M(w) = 200] are measured over the whole composition range. The temperature dependence of density and dynamic viscosity for neat [QuatGly-OEt][EtOSO(3)] and its binary mixture can be described by an empirical polynomial equation and by the Vogel-Tammann-Fucher (VTF) equation, respectively. The thermal expansion coefficient of the ILs is ascertained using the experimental density results, and the excess volume expansivity is evaluated. The negative values of excess molar volume for the mixture indicate the ion-dipole interactions and packing between IL and PEG oligomer. The results of binary excess property (V(m) (E) ) and deviations (Δη, Δ(x)n, Δ(Ψ)n, Δ(x)R, and Δ(Ψ)R) are discussed in terms of molecular interactions and molecular structures in the binary mixture.     

Orientation effect on sign and magnitude of excess thermodynamic functions of non electrolyte solutions at different temperatures (303.15 K, 308.15 K,and 313.15K)

Experimental values of the density and viscosity have been measured for binary mixtures of N-ethylaniline with isomeric butanols (1-butanol, 2-butanol, 2-methyl-1-propanol and 2-methyl-2-propanol) at 303.15, 308.15 and 313.15 K over the entire mole fraction range. These data, the excess molar volumes, and deviation viscosity for the binary systems at the above-mentioned temperatures were calculated and fitted to Redlich-Kister equation to determine the fitting parameters and the root-mean-square deviations. The excess molar volumes, deviation viscosity and excess Gibbs energy of activation of viscous flow have been analyzed in terms of acid-base interactions, hydrogen bond, and dipole-dipole interaction between unlike molecules. The results obtained for dynamic viscosity of binary mixtures were used to test the semi-empirical relations of Grunberg-Nissan, Katti-Chaudhri, and Hind et al. equations.     

自倍频NYAB晶体折射率n_o,n_e和折射率温度系数的测量

报道用最小偏向角和固定入射角相结合的方法测量NYAB晶体的折射率n_0,n_e,给出色散方程。另一方面也给出了n_0和n_e的温度系数的测量结果。     

巴豆酸乙酯与乙醇混合液密度和粘度的测定及关联

主要介绍了3-羟基丁酸乙酯合成过程中的相关物系的物性测定.在常压下采用U形振动管密度计测定了巴豆酸乙酯与乙醇的混合液在293.15～343.15 K下的密度,用乌氏粘度计测定了此混合溶液在293.15～343.15 K下的粘度,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混合粘度的变化Δη,V E和Δη这些值均为负值.同时对不同温度下的超额体积与组成的关系,粘度变化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5%;说明此方程可适用于回归两相体系中上述的物性数据.     

Thermodynamic properties of 1‐ETHYL‐3‐methylimidazolium methanesulphonate with aromatic sulphur,nitrogen compounds at T = 298.15–323.15 K and P = 1 bar

This work investigates the ability of 1‐ethyl‐3‐methylimidazolium methanesulphate ([EMIM][MeSO₃]) as a green and tuneable solvent for denitrification and desulphurisation studies. Experimental density, surface tension and refractive index data have been measured for the following systems: [EMIM][MeSO₃] (1) + pyridine (2), [EMIM][MeSO₃] (1) + pyrrole (2), [EMIM][MeSO₃] (1) + quinoline (2), [EMIM][MeSO₃] (1) + indoline (2), [EMIM][MeSO₃] (1) + thiophene (2) and [EMIM][MeSO₃] (1) + water (2) over the entire mole fraction of [EMIM][MeSO₃] at T = 298.15–323.15 K and P = 1 bar. Further from experimental density, surface tension and refractive index, coefficient of thermal expansivity, excess molar volume, deviation of surface tension and refractive index deviation were also calculated. It was found that the heteroaromatic nitrogen/sulphur compounds are completely miscible in [EMIM][MeSO₃]. The surface tension values were found to increase while the refractive index decreases with increasing mole fraction of [EMIM][MeSO₃]. The experimental values for surface tension increased in the order: pyridine > thiophene > pyrrole > indoline > quinoline > water and for refractive index: pyridine > pyrrole > indoline > quinoline > thiophene > water. It was found that the composition of [EMIM][MeSO₃] has a greater influence than temperature in deciding the surface, optical and thermodynamic properties for similar molecular interaction such as IL–thiophene and IL–pyrrole than dissimilar molecules such as IL–water. Further quantum chemical‐based COSMO‐RS tool was used to estimate the activity coefficient at different composition. © 2012 Canadian Society for Chemical Engineering