甲烷在水-叔丁醇混合溶剂中的溶解度

在303.15 K、313.15 K、323.15 K、333.15 K温度下，0－6 MPa压力范围内测定了甲烷在水－叔丁醇混合溶剂中的溶解度．溶剂中叔丁醇的摩尔分数(x_(TBA))从0到1．结果表明，在温度和溶剂组成一定条件下，甲烷的溶解度随其分区的增加而增大，随x_(TBA)的增加，在富水区内，甲烷的溶解度变化较缓慢，当x_(TBA)超过某值时，甲烷的溶解度随x_(TBA)的增加而增大，并且幅度较大；在x_(TBA)约为0－0.045范围内，甲烷的溶解度随温度增加而减小，x_(TBA)约在0.045－0.15范围内，溶解度随温度增加而增加，x_(TBA)约在0.15～1.0范围内，溶解度随温度增加而减小．根据溶解度与温度和溶剂组成的关系可以推测，在303.15－333.15 K、0－6 MPa范围内，水－叙丁醇混合溶剂中仍存在笼合物结构．根据溶解度与温度、压力的关系讨论了甲烷在此混合溶剂中的亨利常数、偏摩尔体积、标准溶解自由能、标准溶解焓和标准溶解熵．     

反气相色谱法测定离子液体1-己基-3-甲基咪唑三氟甲磺酸盐的热力学参数

采用反气相色谱法研究了343.15~373.15 K温度范围内离子液体1-己基-3-甲基咪唑三氟甲磺酸盐([HMIM]OTF)的热力学参数。根据18种探针溶剂的保留时间计算出探针溶剂与[HMIM]OTF之间的摩尔吸附焓、无限稀释的摩尔混合焓、摩尔蒸发焓、质量部分活度系数、Flory-Huggins相互作用参数及[HMIM]OTF的溶解度参数。结果表明,所选溶剂中正构烷烃、四氢呋喃、乙醚、环己烷和苯为[HMIM]OTF的不良溶剂;二氯甲烷、丙酮、氯仿、乙酸乙酯、四氯化碳、乙酸甲酯、甲苯和甲醇为[HMIM]OTF的良溶剂;运用外推法得到了室温(298.15 K)时[HMIM]OTF的溶解度参数为20.74 (J/cm³)^0.5。本研究为离子液体的应用及相关工作提供了参考。     

反相气相色谱法测定高密度聚乙烯溶解度参数

采用反相气相色谱(IGC)技术测定了高密度聚乙烯(HDPE)在303.15～343.15 K温度范围内的溶解度参数(δ2)及相关指标。以正己烷(n-C6)、正庚烷(n-C7)、正辛烷(n-C8)、正壬烷(n-C9)、三氯甲烷(CHCl3)及乙酸乙酯(EtAc)作为探针分子溶剂,经计算获得了探针溶剂的比保留体积(V0g)、摩尔吸收焓(ΔHS1)、无限稀释摩尔混合焓(ΔH∞l)、摩尔蒸发焓(ΔHv)、无限稀释活度系数(Ω∞1)以及探针溶剂与HDPE的Flory-Huggins相互作用参数(χ∞1,2)等指标。结果表明,上述6种探针溶剂在测定温度范围内均为HDPE的不良溶剂。此外,还推导出了HDPE在室温(298.15 K)下的溶解度参数δ2为19.00 (J/cm3)0.5。     

内压与Henry常数

建立了一个气体溶解度的新模型,它实际上是Pierotti理论的修正,按照这个模型,稀溶液中的溶质被视为虚拟的完全气体,Henry常数则是1mol完全气体的压力与一个Boltzmann因子的乘积,这个因子取决于溶质分子周围溶剂的内压。对若干气体在有机溶剂和聚合物中溶解度数据检验结果表明,这个模型能满意地用来描述Henry常数随温度的变化规律。计算得到的稀溶液形成的偏摩尔热力学函数也与实验值吻合。     

凝固点降低法研究某些脂肪胺的自缔合作用

本工作利用计算机技术改进加热式凝固点测量装置的数据采集系统. 改进后装置的混合物凝固点测量再现性为±0.001 K; 溶剂偏摩尔过量自由能测量再现性为±0.1 J.mol~(-1). 用凝固点降低法测量正丙胺、异丙胺、正丁胺, 异丁胺、正戊胺、异戊胺、二乙胺、二异丙胺、三乙胺、三正丁胺分别与苯和对二甲苯构成二元混合物的溶剂活度系数. 并使用一个包含物理相互作用的三参数连续缔合模型拟合实验数据. 结果表明该模型能较好地刻画所研究的二元缔合混合物。     

超临界二氧化碳与叔丁醇二元体系气液溶解度模型研究

采用固定体积可视观察法测量装置,在50～80℃温度范围内测定了CO2与叔丁醇于不同压力下的平衡数据.通过对高压状态下CO2在液相中的溶解度和叔丁醇在气相中的溶解度模型的研究,对亨利定律和Chrastil半经验溶解度方程进行了改进,提出了分别适合于高压状态下CO2与叔丁醇二元体系的相互溶解度模型.其中CO2在液相中的溶解度可用三次多项式模型关联,其形式为:Pco2=A+B1·xco2+B2·x2co2+b3·x3co2.叔丁醇在O2中的溶解度可用改进的Chrastil半经验溶解度方程进行模拟,其形式为C=ρk·exp(a/T)+b+c·ρm.结果表明,提出的气相溶解度方程和液相溶解度方程与实验数据有着较高的拟合相关系数和精度.     

反气相色谱测定双阳离子型离子液体的溶解度参数

采用反气相色谱法,于343.15 K到363.15 K温度下测定了双阳离子型离子液体1,10-双(N-甲基咪唑鎓)癸烷六氟磷酸盐［C10(MIM)2］［PF6］2的溶解度参数。以正辛烷、正十二烷、正十四烷和正十六烷为探针溶剂,计算了探针溶剂的特性保留体积(V0g)、摩尔吸收焓(ΔHS1)、无限稀释摩尔混合焓(ΔH∞1)、摩尔蒸发焓(ΔHv)、无限稀释活度系数(γ∞12)以及探针溶剂与［C10(MIM)2］［PF6］2的Flory-Huggins相互作用参数(χ∞12),测得该离子液体的溶解度参数(δ2)为15.01 (J\5cm~3)1/2。这一结果对研究离子液体的溶液性质和应用有指导作用。     

反气相色谱法表征离子液体1-己基-3-甲基咪唑四氟硼酸盐的热力学参数

采用反气相色谱法(IGC)表征了离子液体(IL)1-己基-3-甲基咪唑四氟硼酸盐([HMIM]BF₄)在343.15~373.15 K温度范围内的热力学参数.使用了一系列不同化学结构的探针分子测定[HMIM]BF₄与溶剂之间的相互作用力.根据探针分子的保留时间计算得到探针分子与[HMIM]BF₄之间的Flory-Huggins相互作用参数、摩尔吸附焓、无限稀释摩尔混合焓、摩尔蒸发焓、无限稀释活度系数以及[HMIM]BF₄的溶解度参数.结果表明,n-C₆、n-C₇、n-C₈、n-C₉、乙醚、四氢呋喃、苯、环己烷为[HMIM]BF₄的不良溶剂;甲苯、间二甲苯、甲醇、乙醇、二氯甲烷、四氯化碳、氯仿、丙酮、乙酸乙酯、乙酸甲酯为[HMIM]BF₄的良溶剂.运用外推法得到了[HMIM]BF₄在室温(298.15K)时的溶解度参数为23.70 (J·^-3)^0.5.实验结果证明反气相色谱法是一种简便准确的获得离子液体热力学参数的方法.获得的热力学参数体现了这种离子液体与探针分子之间的相互作用力.本研究为离子液体的进一步应用提供了参考.     

溶剂化的热力学集团展开理论

把二元溶液的过剩内能（excess energy）分成溶剂-溶剂、溶剂-溶质及溶质-溶质相互作用部分。利用集团展开方法给出了二元溶液在正则系综的配分函数的表达式,利用该表达式得到了溶质的偏摩尔内能(partial molar energy)和偏摩尔熵(partial molar entropy)的表达式。在无限稀溶液情形,过剩偏摩尔内能的溶剂-溶剂部分又称重组织内能（reorganization energy）,它反映了溶质存在时对其周围溶剂分子之间的相互作用能的影响。研究表明,在溶质的粒子数密度相对较大时,溶质分子之间的相互作用将影响过剩偏摩尔内能的溶剂-溶剂部分,对于稀溶液,过剩偏摩尔内能的溶剂-溶剂部分与溶质的摩尔分数成线性关系。对低密度二元溶液,溶质的过剩偏摩尔内能和过剩偏摩尔熵也与溶质的摩尔分数成线性关系。     

反气相色谱法表征离子液体1-己基-3-甲基咪唑四氟硼酸盐的热力学参数（英文）

采用反气相色谱法(IGC)表征了离子液体(IL)1-己基-3-甲基咪唑四氟硼酸盐([HMIM]BF4)在343.15~373.15 K温度范围内的热力学参数。使用了一系列不同化学结构的探针分子测定[HMIM]BF4与溶剂之间的相互作用力。根据探针分子的保留时间计算得到探针分子与[HMIM]BF4之间的Flory-Huggins相互作用参数、摩尔吸附焓、无限稀释摩尔混合焓、摩尔蒸发焓、无限稀释活度系数以及[HMIM]BF4的溶解度参数。结果表明,n-C6、n-C7、n-C8、n-C9、乙醚、四氢呋喃、苯、环己烷为[HMIM]BF4的不良溶剂;甲苯、间二甲苯、甲醇、乙醇、二氯甲烷、四氯化碳、氯仿、丙酮、乙酸乙酯、乙酸甲酯为[HMIM]BF4的良溶剂。运用外推法得到了[HMIM]BF4在室温(298.15K)时的溶解度参数为23.70(J·cm-3)0.5。实验结果证明反气相色谱法是一种简便准确的获得离子液体热力学参数的方法。获得的热力学参数体现了这种离子液体与探针分子之间的相互作用力。本研究为离子液体的进一步应用提供了参考。     

Solubility of Fumaric Acid in Aqueous Alcohol Solutions

The solubility of fumaric acid in aqueous alcohol solutions was experimentally measured over the temperature range of (278.15–333.15) K by employing an analytical stirred-flask method. The experimental data showed that the solubility of fumaric acid in the binary mixtures increases with increases of both temperature and mass fraction of the organic solvents. The experimental data were well correlated with the modified Apelblat equation and the Buchowski–Ksiazaczak λh equation. In addition, the calculated solubilities showed good agreement with the experimental results. It was found that the modified Apelblat equation gave better correlation results than the Buchowski–Ksiazaczak λh equation. The experimental results should be useful for optimizing the process of purification of fumaric acid in industry.     

The effect of temperature on the solubility of benzoic acid derivatives in water

Using a laser monitoring observation technique, solubilities of o-nitro-benzoic acid, p-hydro-benzoic acid, p-methyl-benzoic acid and m-methyl-benzoic acid in water have been measured in the temperature range 290.15–323.15 K. The experimental data are regressed with the Wilson equation and the λH equation. The experimental results show that solubilities of these compounds in the range of 10⁻⁴–10⁻⁵ mole fraction in water, increase significantly with temperature. Except for o-nitro-benzoic acid, the solubility data are described adequately with the Wilson equation. The λH equation gives good agreement with all experimental data. The results indicate that the molecular structure and interactions affect the solubilities significantly.     

4-(Methylsulfonyl)benzaldehyde Solubility in Binary Solvent Mixtures of Acetonitrile + (Methanol,Ethanol and Isopropanol): Determination and Modelling

The solubilities of 4-(methylsulfonyl)benzaldehyde in the binary mixed solvents acetonitrile + methanol, acetonitrile + ethanol and acetonitrile + isopropanol were determined experimentally using an isothermal dissolution equilibrium method within the temperature range from 283.15 to 318.15 K under atmospheric pressure. The solubility of 4-(methylsulfonyl)benzaldehyde increased with increasing temperature and mass fraction of acetonitrile in each binary system. At the same temperature and mass fraction of acetonitrile, the mole fraction solubility of 4-(methylsulfonyl)benzaldehyde is greater in (acetonitrile + methanol) than in the other two mixed solvents. The solubility data were correlated using the CNIBS/R-K model, Jouyban–Acree model, van’t Hoff–Jouyban–Acree model, Apelblat–Jouyban–Acree model, Ma model and Sun model. The maximum values of relative average deviation (RAD) and root-mean-square deviation (RMSD) are 1.53% and 1.17 × 10^?4, respectively. All of the selected models provided good representation of the experimental solubilities. Furthermore, the standard enthalpies of dissolution were calculated. The dissolution process for 4-(methylsulfonyl)benzaldehyde in these mixed solvents is endothermic. The experimental solubility and the models presented in this work are important for the production and purification of 4-(methylsulfonyl)benzaldehyde.     

Effect of Different Salts on the Solubilities of Benzene and Diphenyl in t—Butyl Alcohol—Water Mixture and Hydrophobic Interaction

The solubilities of benzene and diphenyl in mixed solvents of t-butyl alcohol (TBA) and water with different salts have been determined at T=298.15,303.15,308.15 and 313.15K.The molar fraction of TBA [x(TBA)] in mixed solvent is 0.045,and the molality of the salts (ms) in mixed solvents are 0.000,0.250,0.500,0.750 and 1.000mol/kg ,respectively.The standard Gibbs energies of solution of benzene and diphenyl in the mixed solvents have also been calculated based on the solubility data.The effects of different salts on the hydrophobic interaction (HI) for benzene-benzene pair in the systems were discussed.     

Study on Mass Transfer of Isopropylbenzene and Oxygen in a Two-Phase Partitioning Bioreactor in the Presence of Silicone Oil

A two-phase partitioning bioreactor to treat gas effluents polluted by volatile organic compound has been developed. In this work, both the mass transfer of isopropylbenzene (IPB) and oxygen have been considered in relation to their influence on the hydrodynamics of the reactor and the type of silicone oils used as a second phase. The synergistic effect of silicone oil and stirrer speed on the global oxygen mass transfer coefficient (K _L a) and gas holdup (up to 12%) have been investigated. The addition of 10% of low viscosity silicone oil (10 cSt) in the reactor does not significantly affect the oxygen transfer rate. The very high solubility of IPB in the silicone oil leads to an enhancement of driving force term, especially for high fraction of silicone oil. However, it does not seem useful to exceed a volume fraction of 10% since K _L a _IPB decreases sharply at higher proportions of silicone oil. K _L a _IPB and K _L a _O2 evolve in the same way with the proportion of silicone oil. These results confirm the potentialities of our bioreactor to improve both the oxygen and pollutant gas transfer in the field of the treatment of gaseous pollutants, even for highly concentrated effluents.     

Solubility of gallic acid in liquid mixtures of (ethanol + water) from (293.15 to 318.15) K

The solubility of gallic acid in (water + ethanol) binary solvents was determined from (293.15 to 318.15) K at atmospheric pressure using a thermostatted reactor and UV/vis spectrophotometer analysis. The effects of binary solvents composition and temperature on the solubility were discussed. It was found that gallic acid solubility in (water + ethanol) mixed solvents presents a maximum-solubility effect. Two empirical equations were proposed to correlate the solubility data. The calculated solubilities show good agreement with the experimental data within the studied temperature range. Using the experimentally measured solubilities, the thermodynamic properties of dissolution of the gallic acid such as Gibbs energy (Δ_solG°), molar enthalpy of dissolution (Δ_solH°), and molar entropy of dissolution (Δ_solS°) were calculated.     

Commentary On “Extended Hildebrand Approach: An Empirical Model for Solubility Prediction of Etodolac in 1,4-Dioxane and Water Mixtures”

Several mathematical errors in the published paper by Rathi and Deshpande (J Solution Chem 43:1886–1903, 2014) are identified. The errors concern the incorrect conversion of mass fraction to volume fraction concentrations of 1,4-dioxane, the incorrect conversion of mole fraction solubilities to molar solubilities of Etodolac, and the incorrect calculation of the ideal mole fraction solubility of Etodolac.     

Experimental determination of oxygen and nitrogen solubility in organic solvents up to 10 MPa at temperatures between 298 K and 398 K

Oxygen solubility in methanol, n -propanol, dibutyl ether, toluene, and octane, and nitrogen solubility in ethanol, n -propanol and 2-methyltetrahydrofuran was measured at pressures up to 10 MPa in the temperature range between 298 K and 398 K using the static synthetic method. The experimental results were used to extend the range of applicability of the Soave–Redlich–Kwong (PSRK) model for the prediction of air solubility in organic solvents and solvent mixtures by fitting the missing gas–solvent group interaction parameters. The required pressure range of gas solubility data for fitting the PSRK group interaction parameters was defined by analysing the significance of the data for the optimized parameters. The applied experimental method was analysed in detail since its use at higher pressures requires the consideration of the partial molar volumes of the dissolved gases when solving the mass and volume balance equations during the data treatment.