Densities,conductivities, and viscosities of aqueous solutions of N-hexyl,methylpyrrolidinium bromide and N-butyl,methylpyrrolidinium bromide at different temperatures

The densities, conductivities, and viscosities were measured for ternary solutions of N-hexyl, methylpyrrolidinium bromide ([PP1,6]Br)-N-butyl,methylpyrrolidinium bromide ([PP1,4]Br)-H2O and its binary...     

298.15K时甘露醇-山梨醇-葡萄糖-水四元系及其三元系的密度和黏度

To check the applicabilities of the simple density equation and viscosity equation in the semi-ideal solution theory to nonelectrolyte solutions, the densities and viscosities were measured for the quaternary system mannitol-sorbitol-D-glucose-HzO and its ternary subsystems mannitol-D-glucose-H2O and sorbitol-D-glucose-H2O at 298.15K. The results were used to test the applicability of the simple equations for the density and viscosity of the multicomponent nonelectrolyte solution. The agreements between the predicted and measured results are good.     

由二元亚系的数据预测混合电解质水溶液的活度系数

The simple equation relating the activity coefficient of each solute in mixed electrolyte solution to its value in binary solutions under isopiestic equilibrium was tested by comparison with the experimental data for the 18 electrolyte solutions consisting of 1：1, 1：2, and 1：3 electrolytes. The isopiestic measurements were made on the quaternary system BaCl2-NH4Br-NaI-H2O and its ternary subsystems NaI-NH4Br-H2O, NaI-BaCl2-H2O, and NH4Br-BaCl2-H2O at 298.15K. The results were used to test the applicability of the Zdanovskii＇s rule to the mixed electrolyte solutions which contain no common ions, and the agreement is excellent. The activity coefficients of the solutes in the above quaternary and ternary systems calculated from the above-mentioned simple equation are in good agreement with the Pitzer＇s equation.     

Electrical conductivities for four ternary electrolyte aqueous solutions with one or two ionic liquid components at ambient temperatures and pressure

Thiswork provides amethod to explore the transport property of the electrolyte aqueous solutionswith one or two ionic liquids, especially focus on their electrical conductivity. The conductivities were measured for the ternary systems NaCl–[C₆mim][Cl] (1-hexyl-3-methylimidazolium chloride)–H₂O, [C₆mim][BF₄]–[C₆mim][Cl]–H₂O, NaNO₃–[C₆mim][BF₄](1-hexyl-3-methylimidazolium tetrafluoroborate)–H₂O, and [C₄mim][BF₄] (1-butyl-3- methylimidazolium tetrafluoroborate)–[C₆mim][BF₄]–H₂O, and their binary subsystems NaNO₃–H₂O, NaCl–H₂O, [C₆mim][BF₄]–H₂O, [C₆mim][Cl]–H₂O, and [C₄mim][BF₄]–H₂O, respectively. The conductivities of the ternary systems were also determined using generalized Young's rule and semi-ideal solution theory in terms of the data of their binary solutions. The comparison showed that the two simple equations provide good predictions for conductivity of mixed electrolyte solutions and the mixed ionic liquid solutions based on the conductivity of their binary subsystems.     

含离子液体溴化1-丙基-3-甲基咪唑的二元和三元体系的蒸气压测定

Vapor pressure values of binary systems water ＋ ethanol, water ＋ ionic liquid 1-propyl-3- methylimidazolium bromide （[PMIM] [Br]）, ethanol ＋ [PMIM] [Br] and ternary system water ＋ ethanol ＋ [PMIM] [Br] at different temperatures were measured by using a modified boiling point method in various concentrations of （16.66%, 33.7%）, （17.4%, 33.9%） and （16.5%, 32%） mass percent of ionic liquid, respectively. The experimental vapor pressures of solvent were well correlated by the Antoine-type equation, and the overall average absolute deviation （AAD） was found to be 0.39%. The experimental results for mixtures containing ionic liquid indicate that the vapor pressure of the solvents can be decreased noticeably to different extent due to the affinity difference between ionic liquid and solvent, which is similar to the salt effect of common inorganic salts. As a result, ionic liquid may find industrial applications in extractive distillations for the system with a low separation factor or even for an azeotropic mixture.     

Measurement of thermal conductivity,viscosity and density of ionic liquid [EMIM][DEP]-based nanofluids☆

This article studied experimentally the effect of multi-wall carbon nanotubes(MWCNTs)on the thermo physical properties of ionic liquid-based nanofluids.The nanofluids were composed of ionic liquid,1-ethyl-3-methylimidazolium diethylphosphate [EMIM][DEP],or its aqueous solution[EMIM][DEP](1)+ H_2O(2)and MWCNTs without any surfactants.The thermal conductivity,viscosity and density of the nanofluids were measured experimentally.The effects of the mass fraction of MWCNTs,temperature and the mole fraction of water on the thermo physical properties of nanofluids were studied.Results show that the thermal conductivity of nanofluids increases within the range of 1.3%–9.7% compared to their base liquids,and have a well linear dependence on temperature.The viscosity and density of the nanofluids exhibit a remarkable increase compared with those of the base liquids.Finally,the correlation of the effective thermal conductivity and viscosity of the nanofluids was made using the models in the literatures.     

Determination of physical properties for the mixtures of [BMIM]Cl with different organic solvents

Physical properties including refractive index, density, viscosity and conductivity for binary mixtures of 1-butyl-3-methyl imidazolium chloride ([BMIM]Cl) and different organic solvents at 298.15 K have been investigated. Ex-cess molar volumes have been calculated and obtained data has been fitted by the Redlich–Kister equation. The density and refractive index were found to increase with increasing concentration of [BMIM]Cl, however, excep-tions do exist as in the case of dimethyl sulfoxide (DMSO)/[BMIM]Cl. For DMSO/[BMIM]Cl, the density decreases with increasing concentration. The addition of different organic solvents was able to disrupt the interactions within mixtures, leading to free mobility of ions. The free mobility of ions has been found to enhance conductivity and decrease viscosity to varying extents in al mixtures studied. It has been observed that solubility parameters, dielectric constants and composition of the solvents used play a vital role in determining the resultant properties. The data obtained wil play an important role in understanding the effect of the addition of organic solvents in ILs to enhance their applicability.     

对二甲苯与环己烷、正庚烷、正辛烷、环丁砜和N-甲基-2-吡咯烷酮和乙酸二元混合物在303．15K和323．15K的超额体积和黏度

Experimental data on density and viscosity at 303.15K and 323.15K are presented for the binary mixtures of p-xylene with cyclohexane, n-heptane, n-octane, sulfolane, N-methyl-2-pyrrolidone and acetic acid. From these data, the excess molar volume and deviations in viscosity have been calculated. The computed quantities have been fitted to the Redlich-Kister Equation to derive coefficients and estimate the standard error values. Results are discussed in terms of intermolecular interactions.     

离子液体[BMIM][DBP]+水+甲醇/乙醇三元工质溶液蒸汽压的测量和预测(英文)

The ionic liquid, 1-butyl-3-methylimidazolium dibutylphosphate ([BMIM][DBP]) was prepared and the vapor pressures of three set of binary solutions H2O(1)/CH3OH(1)/C2H5OH(1) + [BMIM][DBP](2) were measured at different temperature and in the ILs mole fraction range from 0.1 to 0.6 with a static equilibrium apparatus. The measured vapor pressures were correlated with Non-Random Two Liquid (NRTL) activity coefficient model and the average relative deviations (ARD) between experimental and correlated vapor pressures for these binary solutions were 3.19%, 2.42% and 2.95%, respectively. Then, the vapor pressures of two set of ternary solutions H2O(1) + CH3OH(2)/C2H5OH(2) + [BMIM][DBP](3) were measured with an inclined boiling apparatus and further predicted with NRTL activity coefficient model based on the binary interaction parameters coming from fitting the vapor pressures of the binary solutions. The results indicated that the ternary solutions containing [BMIM][DBP] were shown a strong negative deviation from Raoult’s Law when the mole fraction of [BMIM][DBP] was larger than 0.2, which meant that ternary solutions could absorb the refrigerant vapors at the same or below solution temperature. Meanwhile, the average relative deviations between experimental and predicted vapor pressures for ternary solutions were 2.92% and 3.06%, respectively. Consequently, the NRTL active coefficient model used for non-electrolyte solutions was still valid for predicting vapor-liquid equilibrium of binary or ternary solutions containing ILs.     

Determination of Vapor Pressures for Binary and Ternary Mixtures Containing Ionic Liquid 1-propyl-3-methylimidazolium Bromide

Vapor pressure values of binary systems water + ethanol, water + ionic liquid 1-propyl-3-methylimidazolium bromide ([PMIM][Br]), ethanol + [PMIM][Br] and ternary system water + ethanol + [PMIM][Br] at different temperatures were measured by using a modified boiling point method in various concentrations of (16.66%, 33.7%), (17.4%, 33.9%) and (16.5%, 32%) mass percent of ionic liquid, respectively. The experimental vapor pressures of solvent were well correlated by the Antoine-type equation, and the overall average absolute deviation (AAD) was found to be 0.39%. The experimental results for mixtures containing ionic liquid indicate that the vapor pressure of the solvents can be decreased noticeably to different extent due to the affinity difference between ionic liquid and solvent, which is similar to the salt effect of common inorganic salts. As a result, ionic liquid may find industrial applications in extractive distillations for the system with a low separation factor or even for an azeotropic mixture.     

Physical and electrochemical properties of 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium iodide,and 1-butyl-3-methylimidazolium tetrafluoroborate

The density, viscosity, refractive index, heat capacity, heat of dilution, ionic conductivity, and electrochemical stability of 1-butyl-3-methylimidazolium bromide ([bmim][Br]), 1-butyl-3-methylimidazolium iodide ([bmim][I]), and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF₄]) were measured at room temperature or over a temperature range of 293.2 to 323.2 K. The density and refractive index values of [bmim][I] appeared to be the highest among three ionic liquids (ILs). However, the experimental viscosity values of [bmim][Br] were higher than those of [bmim][BF₄], while the heat capacities and heats of dilution of [bmim][BF₄] were higher than those of [bmim][Br]. The cyclic voltammogram of [bmim][br] and [bmim][BF₄] indicated electrochemical windows in the stability range from 2.7 V of [bmim][[Br] to 4.7 V of [bmim][BF₄].     

Thermal and electrochemical properties of morpholinium salts with bromide anion

The present work is a study of the thermal properties and electrochemical stabilities of N-ethyl-N-methylmorpholinium bromide ([Mor_1,2][Br]), N-butyl-N-methylmorpholinium bromide ([Mor1_1,4][Br]), N-octyl-N-methylmorpholinium bromide ([Mor1_1,8][Br]), N-dodecyl-N-methylmorpholinium bromide ([Mor1_1,12][Br]), and N,N-dihydroxyethylmorpholinium bromide ([DHEMor][Br]). The melting points, decomposition temperatures, and electrochemical stabilities of the salts were measured by DSC (differential scanning calorimetry), TGA (thermogravimetric analysis), and CV (cyclic voltammogram), respectively. All salts were decomposed below approximately 230.00 °C and their melting points were above 100.00 °C except [DHEMor][Br], which melted at 75.17 °C. [DHEMor][Br] appeared to possess the most wide liquid-phase range between melting point and decomposition temperature. The electrochemical windows of salts ranged from 3.3 V for [Mor_1,8][Br] to 3.6 V for [Mor_1,4][Br] and thus did not show any noticeable variation with cations used for salt synthesis.     

[NH2-emim]Br/[Bmim]BF4离子液体中二氧化碳的电化学还原

以2-溴乙胺氢溴酸和N-甲基咪唑盐为原料合成了氨基功能化离子液体1-（2-胺乙基）-3-甲基咪唑溴盐（[NH₂-emim]Br）,用¹H NMR和IR对所制备的离子液体进行了表征,测得25℃下[NH₂-emim]Br的黏度26.691 Pa·s、电导率0.1130 mS·cm^-1,CO₂的溶解饱和度82%（摩尔分数）,将不同含量的[NH₂-emim]Br与[Emim]BF₄、[Bmim]BF₄、[Bmim]PF₆组成二元复合离子液体,并用于CO₂电化学还原研究,循环伏安研究表明,CO₂在[NH₂-emim]Br（0.5%）-[Bmim]BF₄复合离子液体中的还原峰电位较[Bmim]BF₄正移0.4 V,还原峰电流增大9倍,黏度降低为0.08227 Pa·s,电导率增大至1.317 mS·cm^-1,是一种较好的CO₂电化学还原离子液体体系。     

Effects of 1-n-tetradecyl-3-methylimidazolium bromide on the properties of polypropylene

In this study, 1-n-tetradecyl-3-methylimidazolium bromide ([C₁₄mim]Br), one kind of imidazolium ionic liquids (imi-IL), was incorporated into polypropylene (PP) via melting blend. The structure and properties of PP/[C₁₄mim]Br blend were investigated by differential scanning calorimetry (DSC), dynamical mechanical analysis (DMA), and thermogravimetric analysis (TGA). DSC results show that the [C₁₄mim]Br has effects on the melting and crystallization process so that PP and PP/[C₁₄mim]Br blends (weight ratio is 100/3) have different melting and crystallization temperature. Results of DMA show that the [C₁₄mim]Br has the effects on the plasticization and crystallization of PP, and the glass transition temperature (T_g) of PP decreases around 11°C when 3 weight shares of [C₁₄mim]Br were incorporated into 100 weight shares of PP. Moreover, both tensile strength and impact strength of PP have been improved reasonably in this situation. TGA also shows the thermal stability of PP is not affected by the [C₁₄mim]Br, which was incorporated into it though its molecule is small. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

[aP4443][Gly]-H2O两元体系物性测定及CO2吸收性能

采用两步法合成了双氨基功能化季鏻类离子液体3-丙胺基-三丁基鏻甘氨酸盐([aP4443][Gly])、3-丙氨基-三丁基鏻丙氨酸盐([aP4443][Ala])和3-丙氨基-三丁基鏻缬氨酸盐([aP4443][Val]),研究了[aP4443][Gly]与水构成的两元体系的粘度和电导率的变化. 结果表明,在298.15~343.15 K温度范围内,随阴离子烷基链增长离子液体粘度增大、电导率减小;随温度升高、含水量增加,[aP4443][Gly]-H2O两元体系的粘度减小、电导率增大. CO2吸收实验表明,添加水后离子液体[aP4443][Gly]对CO2的吸收速率均提高;当水摩尔分数小于0.50时,饱和吸收量增大;当水摩尔分数从0.50增大到0.75时,饱和吸收量减小,说明添加适量水可大幅改善[aP4443][Gly]吸收CO2的行为.     

溴化锂及离子液体水溶液密度、黏度和表面张力测定与计算

常压条件下,实验测定了不同温度（283.15~343.15 K）下吸收制冷/热泵工质对——溴化锂（LiBr）、1-乙基-3-甲基咪唑醋酸盐（[EMIM][OAC]）和1-丁基-3-甲基咪唑硫氰酸盐（[BMIM][SCN]）水溶液的密度、黏度和表面张力,借助线性方程和Vogel-Tammann-Fulcher（VTF）模型,分别成功关联了密度和黏度实验值。研究结果表明：在相同条件下,溴化锂水溶液的密度大于离子液体水溶液的密度,而前者的黏度小于后者;对表面张力,随着溴化锂含量增加,其水溶液的表面张力值增加,而少量离子液体可使水的表面张力快速下降。根据实验黏度和表面张力分别获得了能量势垒和表面熵/焓,表明各水溶液中分子或离子迁移难易程度遵循[EMIM][OAC] > [BMIM][SCN] > LiBr,表面有序性遵循[BMIM][SCN] > [EMIM][OAC] > LiBr。研究结果可为吸收制冷/热泵工质对及低温余热回收系统的设计和计算提供可靠的数据支撑。     

1-氨丙基-3-甲基咪唑溴盐水溶液的汽液相平衡

1-氨丙基-3-甲基咪唑溴盐([APMIm][Br])是一种对CO₂有良好吸收性能的功能型离子液体,在工业中可采用水溶液来实现高效能的吸收和解吸循环过程,因此对其水溶液特性的研究至关重要。对[APMIm][Br]水溶液在中低温度下的汽液相平衡进行了测量,获得可靠的实验数据,从而揭示其水溶液特性。实验温度范围为278.15～348.15 K,[APMIm][Br]在水溶液中质量分数分别为10.0%、20.3%、29.5%、40.0%、57.5%、75.3%、84.0%、88.9%、90.9%。考虑了低温下离子液体分子在水溶液中的强缔合特性,采用带缔合惰化因子的离子液体水溶液活度模型对实验数据进行了拟合,实验值与计算结果符合很好,平均相对误差为2.15%。     

MBr(M=Na,K)在离子液体[Bmim]Br水溶液中的溶解度

为探索溴化1-丁基-3-甲基咪唑([Bmim]Br)离子液体对无机溴化物MBr(M=Na,K)在水中溶解度的影响,采用等温溶解平衡法在常压下测定了298.15~328.15 K范围内MBr在[Bmim]Br(1)+H₂O(2)溶液中的溶解度,考察了离子液体含量对溶解度的影响。实验结果表明,[Bmim]Br的加入会显著降低MBr(M=Na,K)在水中的溶解度,离子液体[Bmim]Br对KBr的盐析作用比对NaBr的盐析作用大。不同温度下的溶解度数据可用Pitzer混合电解质溶液模型进行关联,得到了混合离子相互作用参数以及MBr在混合溶剂中的平均活度因子和溶剂的渗透系数。模型计算的溶解度与实验结果吻合良好,平均活度因子和溶剂的渗透系数均随离子液体含量的增加而增加。