电动势法在电解质溶液的热力学研究中的应用

本文对１９８０年以来电动势法的改进和发展作一简要综述，并从单一电解质，混合电解质，电解质与非电解质的相互作用以及平衡常数等四个方面评述了电动势法在电解质溶液的热力学研究中的应用。     

拟静态法测定混合溶剂的汽化热和汽化熵

讨论了沸点升高法测定混和溶剂化热和汽化熵的原理，并用拟静态法测定了乙醇－丙酮，并－四氯化碳和苯，甲苯三组混和溶剂在不同组成下的正常沸点，根据沸点数据求得了混和泶微分汽化热和汽化熵，实验结果表明，二元混和溶剂与理想溶液偏离不大时，其正常汽化熵符合Ｔｒｏｕｔｏｎ规则。     

葡萄糖和水混合溶液多组分电解质热力学 Ⅱ.HCl-NaCl-d-Glucose-H_2O体系(5—45℃)

本文续前报在恒定溶液总离子强度I=1.00mol·kg~(-1),改变葡萄糖在混合溶液中的质量百分数x=5%、15%和20%的条件下,应用电动势法测定了无液接界电池(A)和电池(B)的电动势: Pt,H_2(1.013×10~5Pa)|HCl(m),d-Glucose(x),H_2O(1-x)|AgCl-Ag (A) Pt,H_2(1.013×10~5Pa)|HCl(m_A),NaCl(m_B),d-Glucose(x),H_2O(1-x)|AgCl-Ag(B) 其中x代表葡萄糖在水中的质量百分数,m_A和m_B分别是HCl和NaCl在混合溶液中的质量摩浓度。利用电池(A)的电动势数据得到了AgCl-Ag电极在d-Glucose-H_2O混合溶液中的标准电极电势Φ_m~0,讨论了HCl的迁移性质,利用电池(B)的电动势数据,确定了HCl在HCl-NaCl-d-Glucse-H_2O体系中的活度系数γ_A,实验结果表明:在恒定总离子强度下,HCl的活度系数服从Harned规则。HCl的迁移自由能与葡萄糖的质量百分数x成线性关系。计算了HCl     

聚电解质溶液热力学性质的研究

本文采用柱形胞腔模型以及Vink的近似方法, 求解聚电解质溶液的Poisson-Boltzmann方程, 得到不同条件下聚离子周围静电势的分布。进而得到了不同条件下聚离子、反离子和同电荷离子的活度系数及溶剂的渗透系数。所得结果与实验值能较好地吻合。     

葡萄糖和水混合溶液多组分电解质热力学II. HCl-NaCl-d-Glucose-H2O体系(5-45 ℃)

The thermodynamic properties of HCl-NaCl-d-Glueose-H_2O system was studied by emf measurement without liquid junction. Pt, H_2(1.013×10~5 Pa)|Hel(m), d-Glucose(x), H_2O(1-x)| Agel-Ag (A) Pt, H_2(1.013×10~5Pa)|HCl(m_A), NaCl(m_B), d-Glucose(x), H_2O(1-x)|AgCl-Ag (B) at the mass percentage of d-Glucose x=5%, 15% and 20% in the mixed solution, from 5 to 45 ℃, for cell (B) at constant total ionic strength I=1.00 mol·kg~(-1). The standard electrode potential of Ag-AgCI in the mixed solution have been determined from cell (A). The activity coefficients of HCl, γ_A, in the mixed solution system have been determined from cell (B). The results show that the activity coefficients of HCl in HCl-NaCl solutions still obeye Harned Rule. The standard transfer Gibbs free energies of HCl have calculated. The primary, secondary and total medium effect of HCl have been calculated.     

水＋3-甲基吡啶＋溴化钠三元溶液动-静态光散射临界行为研究

对水＋3-甲基吡啶＋溴化钠三元电解质溶液的临界跨接行为的认识存在着争议. 部分研究认为由于三甲基吡啶的聚集, 体系存在从非经典的3D-Ising(三维伊辛)行为向经典的平均场行为的非单调跨接; 另一部分研究发现该体系符合3D-Ising临界行为, 并不存在跨接. 采用动-静态光散射研究了溴化钠, 3-甲基吡啶和水三元溶液的临界性质, 得到动态关联长度和静态关联长度, 发现动态关联长度和静态关联长度一致, 且在实验温度范围内(离临界温度0.01～25 K), 体系不违背3D-Ising行为, 也观测不到显著的临界跨接现象.     

聚电解质-磺化聚砜溶液的光散射

本文采用激光小角光散射法,测定了聚电解质-磺化聚砜(钠盐),在分别舍有NaNO_3、LiNO_3、LiCl、NaBr和NaI的DMF中各试样的表现分子量。结果表明,在含有0.07N NaNO_3的DMF中,磺化聚砜的表观分子量接近于试样的真实分子量。     

硝酸钾电解质溶液水化结构的分子动力学模拟

Molecular dynamics simulations were carried out to study the structure of ion clusters and hydration properties of KNO3 solution. The water molecule was treated as a simple-point-charge (SPC) model, and a four-site model for the nitrate ion was adopted. Both the Coulomb and Lennard-Jones interactions between all the charged sites were considered, and the long-range Coulomb electrostatic interaction was treated using Ewald summation techniques. The configuration of ionic pairs, the radial distribution function of the solution, and the effect of solution concentration on ionic hydration were studied in detail. It was found that there are ionic association phenomena in KNO3 solution and that the dimeric, triplet, solvent-separated ion pairs, and other complex clusters can be observed at high ionic concentration condition. As the concentration of solution decreases, the ionic hydration number increases, 5-7 for cation K+ and 3.5-4.7 for anion NO3-, which is in good agreement with former Monte Carlo and time-of-flight neutron diffraction results.     

电解质溶液的分子热力学模型研究进展

"本文从经典溶液理论及半经验模型、近代统计力学理论和分子模拟三大方面阐述了近年来国内外电解质溶液热力学的研究进展。指出电解质溶液的研究已逐渐从经典的溶液理论和半经验模型转向用统计力学理论进行研究, 从电解质的原始模型转向非原始模型。从分子和离子的微观参数出发建立高水平的热力学理论模型, 以预测电解质溶液体系的宏观热力学性质, 是发展的必然趋势。     

Osmotic Coefficients and Activity Coefficients of Nonaqueous Electrolyte Solutions. Part 4. Lithium Bromide, Tetrabutylammonium Bromide, and Tetrabutylammonium Perchlorate in Acetone

Vapor pressure lowering by the addition of lithium bromide (0.03–0.8m), tetrabutylammonium bromide (0.01–0.8m), and tetrabutylammonium perchlorate (0.02–3.6m) to acetone was measured at 25°C with high precision. The experimental data of the corresponding osmotic coefficients are compared to those obtained by the use of Pitzer equations and chemical model calculations. Mean activity coefficients are derived from the osmotic coefficients.     

Osmotic Coefficients and Activity Coefficients of Nonaqueous Electrolyte Solutions. Part 3. Tetraalkylammonium Bromides in Ethanol and 2-Propanol

Vapor pressure lowering by the addition of tetraethylammonium bromide (0.04 to 2.3 m), tetrapropylammonium bromide (0.04–2.7 m), tetrabutylammonium bromide (0.05–2.5 m), bispiperidinium bromide (0.04–0.7 m) to ethanol and tetrapropylammonium bromide (0.04–1.3 m) and tetrabutylammonium bromide (0.03–1.9 m) to 2-propanol was measured at 25°C with high precision. The experimental data of the corresponding osmotic coefficients are compared to those obtained by the use of Pitzer equations and chemical model calculations. Mean activity coefficients are derived from the osmotic coefficients.     

多羟基化合物水溶液渗透系数的测定

The determination of the osmotic coefficients of the aqueous solution of polyhydroxylated compounds such as glycol, glycerol, sucrose and glucose by Vapour Pressure Osmometry at 313, 323 and 333K was carried out over the concentration range of 0.0-2.1mol﹒kg-1 and 0.0-2.0 mol﹒kg-1 respectively. By using a linear least-square fitting routine, the osmotic coefficients were fitted by a simple polynomial equation, It was found that the relation between the experimental results of molal osmotic coefficients Φ and the mass molal concentration of the solution m are in agreement with that from the polynomial fitting at different temperature. Factors which influence the osmotic coefficient such as the number of hydroxyl of polyhydroxylated compounds or the molecule weight of the solute molecules should be further studied, this work will also contribute to the studies of other thermodynamical properties of the aqueous solution of polyhydroxylated compound.     

Osmotic Coefficients and Activity Coefficients of Nonaqueous Electrolyte Solutions. Part 2. Lithium Perchlorate in the Aprotic Solvents Acetone, Acetonitrile, Dimethoxyethane, and Dimethylcarbonate

Vapor pressure lowering by the addition of lithium perchlorate to the aprotic solvents acetone (0.02–0.6 m), acetonitrile (0.05–1.2 m), dimethoxyethane (0.02–0.4 m), and dimethylcarbonate (0.03–1.8 m) was measured at 25°C with high precision. The experimental data for the corresponding osmotic coefficients are compared to those obtained from the Pitzer equations and chemical model calculations. Mean activity coefficients are derived from the osmotic coefficients.     

Osmotic and Activity Coefficients of Nonaqueous Electrolyte Solutions. 1. Lithium Perchlorate in the Protic Solvents Methanol, Ethanol, and 2-Propanol

Vapor pressure lowering by the addition of LiClO₄ to the protic solvents methanol (0.04–5.1 m), ethanol (0.03–1.5 m), and 2-propanol (0.05–1.5 m) was measured at 25°C with high precision. The experimental data of the corresponding osmotic coefficients are compared to those obtained by the use of Pitzer equations and chemical model calculations. Mean activity coefficients are derived from the osmotic coefficients.     

强电解质稀溶液的依数性公式导出及实验验证

讨论了强电解质稀溶液的依数性,即凝固点降低、沸点升高和渗透压。以稀溶液的凝固点降低为例,利用Gibbs-Duhem公式,推导了强电解质稀溶液的凝固点降低公式,并利用Na Cl水溶液的凝固点降低实验验证了该公式的正确性。     

LiCl-NaCl-KCl-H2O溶液体系渗透压的分子动力学模拟

盐湖卤水中含有大量的锂、 钾资源, 发展卤水的渗透压预测模型和方法, 对于资源的综合利用具有重要的指导意义. 本文采用分子动力学(MD)方法结合水溶液渗透压模拟(OPAS)技术, 研究了LiCl-NaCl-KCl-H₂O体系的渗透压模拟方法, 计算了298.15 K下体系多种组成和浓度的渗透压, 并将计算结果与实验值和Pitzer模型计算值进行了对比. 结果显示, 模拟计算值与实验值和Pitzer模型计算值渗透压的趋势基本一致, 包括同种溶液不同浓度和同浓度不同溶液之间的渗透压关系. 该方法可以应用于多元混合物体系对渗透压进行定性和半定量的计算.     

A New Set of Gas/Water Partition Coefficients for the Chloromethanes

Summary. In the literature, there is a considerable number of articles and reviews providing data and information on the solubility of chloromethanes in water. However, the substantial difference between the numerical values given by various authors hinders their practical application. In the current work we present the harmonized results of experimentally determined gas/water partition coefficients of CH₂Cl₂, CHCl₃, and CCl₄, in the temperature range from 278 to 343 K, and with on uncertainty limit of less than 10%.     

在电解质溶液中测定非电解质溶解度的新方法

提出了一种可以同时测定电解质溶液中非电解质的溶解度和饱和溶液水活度的新方法。该法把等压平衡与传统化学分析统一起来,其优点是：（1）将多元饱和溶液中非电解质溶解度的测定转变为共存离子的溶度测定,避开了对非电解质难于进行精确化学分析的难题;（2）可以同时确定所测饱和体系的水活度。用该法测定了NaCl和KCl溶液中甘露醇的溶解度并与文献值进行了比较,结果表明二者符合得很好。     

高分子溶液特性粘度测定的新方法

提出了一个新的一点法测定高分子溶液的特性粘度的经验公式, 并根据文献的一些数据将该公式和常用的程镕时公式进行了比较研究. 结果表明, 该公式具有比程氏公式更高的准确性和广谱性, 还有简单易于操作的优点.