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。     

理想稀溶液的分子模型与Henry系数

提出了一个理想稀溶液的分子模型,并利用Boltzmann分布定律和Laplace方程导出一个简单的Henry系数表示式,它与溶质分子周围溶剂的内压力或溶剂压密切相关。利用Hildebrand内压力方程,并以纯溶剂的摩尔体积代人,关联了11种气体在正十六烷中的Henry系数随温度变化的实验数据。     

从定标粒子理论计算气体的盐效应常数和温度对它的影响

在本刊1979年第1期的“气体在水和非水溶剂中的溶度的定标粒子理论”一文中,作者指出应用气体在盐水溶液中的Henry常数的表式:     

单原子离子溶剂化的研究 Ⅱ. 离子溶剂化吉布斯自由能的理论计算

本文采用单层结构模型的思想, 吸取Born模型的优点, 提出一种新的处理离子与第一溶剂化层溶剂分子间相互作用的方法。所得到的离子溶剂化吉布斯自由能的计算公式考虑了离子-溶剂相互作用能、离子内能和溶剂分子间相互作用能的贡献。对水、DMF和PC中各种类型的离子的计算与实验值符合得比较好。     

十六烷基氯化吡啶溶剂气浮的热力学及动力学研究

研究了表面活性剂十六烷基氯化吡啶(HPC)的溶剂气浮回收动力学及热力学规律。通过测定不同温度及浓度下HPC的表面张力, 得到了HPC在气-液界面的标准吸附表面自由能为-33.17 kJ/mol。HPC的溶剂气浮过程符合一级动力学方程,表观速率常数k的值随气体流速升高而增加,随温度升高而降低。     

气体在水中的溶解机理及溶解度方程

提出气体在水中的两种溶解机理——间隙填充和水合作用。推导出气体溶解度方程的一般形式。讨论了Henry常数与温度、压力、气体的水合平衡常数和气体的分子体积的关系。用甲烷溶解度的实验数据验证了上述理论,结果表明,在20～160℃和小于60MPa条件下,甲烷溶解度的理论计算值与实验值基本一致。     

有机共轭体系电子转移反应的溶剂重组能

应用Marcus双球模型计算溶剂重组能λs时,在AM1法优化给受体几何构型基础上,提出了共轭体系电子云分布的扁球模型,并用统计的方法求出了rD/A.同时依照Miller等的处理办法,结合其他理论及实验证据将电子转移交叉反应中联苯分子的扭转能计入溶剂重组能λs中,从而用实验速率常数拟合出含扭转能的λs值.此实验拟合值与扁球法得到的λs计算值吻合得很好.通过比较理论值与实验值,发现了给受体间距的大小、受体分子的变化、溶剂的不同对λs计算值相对λs实验值的偏差的影响,直接证实了电子给受体的耦合作用,溶剂分子参与的超交换电子转移及溶质溶剂分子表面相互作用等量子因素造成的实际反应体系对溶剂经典连续介质模型的偏离.     

RbCl由H2O至混合溶剂(H2O-DMF)标准迁移熵的测定

电解质迁移热力学性质的测定,对于离子溶剂化的研究具有重要意义.迁移自由能主要反映离子与溶剂分子间的相互作用,迁移熵则主要反映不同溶剂分子间的相互作用,迁移熵随温度及溶剂组成的改变可为溶剂的原有结构推测及溶液秩序改变提供信息.我们曾运用离子选择性电极测定了部分碱金属卤化物在水及含水混合溶剂中的热力学性质[1-3].本文用离子选择性电极方法,通过测定不同温度下电池的标准电动势,根据溶液热力学原理,求得ＲｂＣｌ由Ｈ2Ｏ至混合溶剂(Ｈ2ＯＤＭＦ)的标准迁移自由能ΔＧｔ及其温度系数,计算ＲｂＣｌ的标准迁移熵ΔＳｔ.结果尚未见…     

扩散系数与内压

本文将Eyring的液体粘性流动分子模型推广到了液体混合物,并用热力学方法导出一个无限稀释溶液中溶质的的放散系数与溶剂内压间的关系式.推导表明,扩散所需的空穴大小适为一个溶质分子所占液体的体积.扩散的活化能不仅取决于溶剂对溶质分子的作用能,而且还与在溶剂中形成空穴的难易程度有关.     

278.15至318.15K下二氧化碳在氯化钠葡萄糖水溶液中的溶解度和活度系数

用自行研制的二氧化碳溶解度测量仪在不同温度下测定了二氧化碳在不同氯化钠浓度15%葡萄糖水溶液中的溶解度和活度系数,确定了Henry常数和盐析常数,Henry常数与温度关系的经验方程为lgS=A/T+B+CT,并计算了二氧化碳溶解过程的各个热力学量。     

Solubility of tetrafluoromethane in the ionic liquid [hmim][Tf2N

Experimental results for the solubility of tetrafluoromethane (CF4, R14) in the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([hmim][Tf2N]) are presented for temperatures between 293.3 and 413.3 K, at pressures (gas molalities) up to 9.6 MPa (0.22 mol kg-1). The experimental results were determined with a high-pressure view-cell technique operating on the synthetic method. The experimental data were used to determine Henry's constant of tetrafluoromethane in [hmim][Tf2N]. The results for the Henry's constant (at zero pressure) are correlated (on the molality scale) within the experimental uncertainty (i.e., about 1.1%) by ln(k(0)(H,CF4)/MPa) = 7.537 - 893.8/(T/K) - 0.003977(T/K). Henry's law was also extended to describe the gas solubility at higher pressures. Furthermore, a cubic equation of state was used to correlate the gas solubility over the entire range of experimentally investigated temperature and pressure. Both methods proved suited for a reliable correlation of the new experimental data.     

Solid–liquid phase equilibrium and mixing thermodynamic analysis of coumarin in binary solvent mixtures

The solubility of coumarin in three aqueous solvent mixtures (methanol + water, ethanol + water and acetone + water) was experimentally determined by a gravimetric method at atmospheric pressure. The experimental solubility data were fitted using the modified Apelblat equation, non-random two-liquid (NRTL) equation, the combined nearly ideal binary solvent/Redlich–Kister equation and the Jouyban?Acree equation, respectively. All the equations were proven to be able to correlate the experimental data, and the modified Apelblat equation could obtain better correlation results than the other three models. The solubility of coumarin increases with increase in temperature. At the same temperature, the solubility increases with increase in mole fraction of organic solvents except for the ethanol–water system which shows a unimodal curve. In addition, the apparent thermodynamic properties of the mixing process were calculated based on the NRTL model and the experimental solubility data.     

Prediction of Henry''s constants by the UNIFAC-FV model for hydrocarbon gases and vapors in high-boiling hydrocarbon solvents

The design of absorption processes and gas liquid reactors requires the knowledge of gas solubility data. It is shown that a modified UNIFAC-FV model can be applied to predict Henry's constants for hydrocarbon gases and vapors in high-boiling hydrocarbon solvents. Very good agreement with experimental data has been achieved.     

Interactions of fluorinated gases with ionic liquids: solubility of CF4, C2F6, and C3F8 in trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)amide

The interactions between ionic liquids and totally fluorinated alkanes are investigated by associating gas solubility measurements with molecular simulation calculations. Experimental values for the solubility of perfluoromethane, perfluoroethane, and perfluoropropane in one ionic liquidtrihexyltetradecylphophonium bis(trifluoromethylsulfonyl)amide [P 6,6,6,14][Ntf 2]are reported between 303 and 343 K and close to atmospheric pressure. All mole fraction solubilities decrease with increasing temperature. From the variation of Henry's law constants with temperature, the thermodynamic functions of solvation were calculated. The precision of the experimental data, considered as the average absolute deviation of the Henry's law constants from appropriate smoothing equations, is always better than +/-3%. By the analysis of the differences between the solute-solvent radial distribution functions of perfluoromethane and perfluoropropane obtained by molecular simulation, it was possible to explain why solubility increases with the size of the perfluoroalkane. The trend of solubility is explained on the basis of the location of the solute with respect to the solvent ions as well as on the differences in the solute-solvent energies of interaction.     

环境化工中微弱溶解度测定的新方法

将激光透射原理与化工中溶解度测定方法相结合,提出了一种激光法测定固体在液体中微弱溶解度的新方法.由于激光的稳定性、单向性和灵敏性,使得该种溶解度的测定比传统的目测法更加客观准确.这种新型测定方法除了可以解决传统化工中的数据测定问题,还可以应用于新兴的交叉学科——环境化工领域,尤其适用于环境化工中水溶解度方面的测定.例如,可针对环境保护中有毒有害腐蚀性物质的微弱水溶解度做准确测定.以对苯二甲酸分别在水和醋酸中的溶解为例,测定了300到 445 K温度范围内的微弱溶解度,并采用Wilson和Wilson-T模型关联.后者精度较好,可以作数据内插使用.     

Adsorption of bovine serum albumin on nanosized magnetic particles

A new model was proposed to predict the adsorption equilibrium of mixtures composed of supercritical gases. The adsorbed phase was visualized as a two-dimensional nonideal compressed gas. Pore size distribution was used to describe the energetic heterogeneity of the surface, and the two-dimensional virial equation was used as the local adsorption isotherm. The new model obtained is thermodynamically rigorous because it reduces to Henry's law as pressure approaches zero. The prediction performance of the new model was verified and compared with other models using the experimental data of a ternary mixture of CH4/N2/H2 and two binary mixtures of CH4/C2H4 and CH4/N2. Better performance was shown for all systems tested.     

The influence of gas phase fugacity and solubility on correlation of gas-hydrate formation pressure

The dissociation pressure for single gas-hydrate systems is correlated by van der Waals and Platteeuw's model with a Kihara spherical-core potential for the interaction between water and the guest molecule. By fitting to dissociation pressures along the hydrate-ice-gas-line, Kihara parameters are obtained independent of the mutual solubility of the gas and water. Further, the fugacity coefficients m that region are close to unity so that the Kihara parameters are rather insensitive to the choice of equation of state. By fitting to the ice-line only, we can investigate to what extent the equation of state fugacities influence the calculated dissociation pressures along the hydrate-water gas and hydrate-water-condensate equilibrium lines. By comparing the calculated equilibrium data to the experimental data we can conclude that an accurate prediction of hydrate dissociation pressures requires an equation of stat which gives an accurate correlation of fugacities rather than densities, and that it is necessary to take gas solubility into account even for non-polar gases like nitrogen and methane. Such investigation has not been reported previously. The Kihara parameters for the single gas-hydrate systems are estimated using the thermodynamically stable hydrate structure.     

Fluid phase equilibria in the system n-butane + water

Although the phase equilibria in the system n-butane + water have been studied frequently, a review of the experimental results has revealed serious disagreement among the various investigators. In this work, the data from the literature are supplemented with some new solubility data. These data are then used construct a model, based on Henry's law, for the phase equilibria.