非电解质水溶液黏度的关联

许多化工过程的设计需要估算含水体系的黏度,但目前的黏度关联方法用于含水体系时误差较大.今以作者所在课题组近期提出的非水液体混合物黏度关联方程为基础,通过引入形状因子,得出了一个非电解质水溶液的黏度方程.该方程可用于二元非电解质水溶液黏度的关联,且能利用二元黏度得到的关联参数推算三元非电解质水溶液的黏度.该方程对54个二元非电解质水溶液体系黏度(总计2876个黏度数据点)关联的总平均相对偏差为4.60%;对7个三元非电解质水溶液体系黏度(总计352个黏度数据点)推算的总平均相对偏差为3.75%.结果表明,该方程具有较高的关联精度和推算精度.     

两个四元体系液体混合物表面张力的测定及预测

测定了两个四元体系液体混合物醋酸-丙酮-乙醇-水及醋酸-苯-乙醇-乙酸乙酯在25℃下不同组成的表面张力.测得的数据与作者以前提出的预测公式所计算的结果符合甚佳.     

立方型状态方程结合Eyring理论在液体混合物黏度计算中的应用

Cubic equations of state (EOS) have been combined with the absolute rate theory of Eyring to calculate viscosities of liquid mixtures. A modified Huron Vidal gE-mixing rule is employed in the calculation and in comparison with the van Laar and the Redlich-Kister-type mixing rule. The EOS method gives an accurate correlation of liquid viscosities with an overall average deviation less than 1% for 67 binary systems including aqueous solutions. It is also successful in extrapolating viscosity data over a certain temperature range using parameters obtained from the isotherm at a given temperature and in predicting viscosities of ternary solutions from binary parameters for either polar or associated systems.     

Properties of aqueous salt solutions of polyvinylpyrrolidone. I. Viscosity characteristics

The properties of dilute solutions of polyvinylpyrrolidone (PVP) in aqueous salt solutions have been studied by measurements of intrinsic viscosity [η] in theta and nontheta solvents. Intrinsic viscosities of the polymer solutions were observed to decrease upon addition of a variety of inorganic salts (phosphates, monohydrogen phosphates, carbonates, sulfates, and dihydrogen phosphates). Values of the Huggins constant, k_H, were found to be higher than 0.35 for PVP in pure water at 298 K, whereas in salt solutions they varied from 0.85 to 1.28 in nontheta solvents. Kraemer's constant, k_K, was also determined and k_H-k_K was calculated as 0.78 for PVP in pure water and for aqueous salt solutions of PVP, k_H-k_K = 0.61 at 298 K. k_H values were also higher than the predicted range of 0.5–0.7, and k_H-k_K values were noted to be 0.73 in theta solvents. © 1996 John Wiley & Sons, Inc.     

3-庚3-庚酮+乙酸乙酯、3-庚酮+乙酸丁酯、3-庚酮+TBP、MIBK+TBP二元体系的过量摩尔体积和黏度

常压下测定了3-庚酮+乙酸乙酯、3-庚酮+乙酸丁酯、3-庚酮+磷酸三丁酯（TBP）、4-甲基-2-戊酮（MIBK）+磷酸三丁酯4个二元体系在293.15～318.15 K下的密度和黏度值,计算了二元体系的过量摩尔体积V^E和过量黏度Δη,并用Redlich-Kister方程对V^E和Δη进行了关联。混合溶剂的黏度数据采用Orrick-Erbar(O-E)基团贡献法进行了关联和预测,增加了O-E方法中的(-O)₃-P=O 基团贡献值。结果表明,O-E方法可根据现有的纯溶剂的黏度数据预测得到混合溶剂的黏度,平均误差小于15%。     

Electrochemical preparation and characterization of poly(1-amino-9,10-anthraquinone) films

Poly(1-amino-9,10-anthraquinone), PAAQ, films were prepared by electrochemical oxidation of the monomer, AAQ, in acetonitrile using LiClO₄ as supporting electrolyte. The influence of scan repetition, scan rate and monomer concentration on the formation of polymer film was studied. The electrochemical behavior of the formed polymer films was investigated in both non-aqueous and aqueous media. The prepared films were found to be more stable in organic solvents than in aqueous solutions. The investigated organic solvents are methanol, ethanol, acetone, carbon tetrachloride, benzene, and chloroform. The polymer film shows electrochemical response in both non-aqueous and aqueous media. In non-aqueous solutions it has a wide potential range of electroactivity (from −1.5 to +1.3 V). In aqueous media the polymer film shows electrochemical response in the potential range between −0.3 and +1.3 V only. The presence of quinone units suggests potential applications in diverse areas such as electrocatalytic processes and lithium ion batteries.     

含盐体系汽液平衡数据的检验

引　言在含盐体系ＶＬＥ实验中 ,数据精确度一般比无盐体系差 ,其检验更为必要 .为对含盐体系ＶＬＥ数据进行检验 ,Ｊａｑｕｅｓ与Ｆｕｒｔｅｒ[1] 曾将虚拟二元法与Ｈｅｒｉｎｇｔｏｎ法相结合提出一个饱和盐溶液恒压ＶＬＥ数据的检验方法 .该方法不仅在应用上有较大局限 ,其理论依据也是近似性的 .目前文献中积累了许多盐未饱和条件下的ＶＬＥ数据 ,其中绝大部分是在双液比固定条件下测定的 .由于缺少检验方法 ,以致这些数据在测定及使用过程中均未能得到检验 .对无盐体系而言 ,Ｇｉｂｂｓ -Ｄｕｈｅｍ方程可以作为ＶＬＥ数据普遍满足的必…     

Surface tension prediction and thermodynamic analysis of the surface for binary solutions

The surface tensions of 100 aqueous and 200 non-aqueous binary solutions are correlated by Shereshefsky model and excellent results are obtained. The average percent deviations are about ∼1.8% for aqueous and ∼0.56% for non-aqueous binary solutions. The free energy change in the surface region is calculated and is used to obtain the excess number of molecular layers in the surface region. Furthermore, the model is used to derive an equation for the standard Gibbs energy of adsorption. Where experimental data is available for the standard Gibbs energy of adsorption, the agreement between the calculated and the experimental data is found to be very good.     

Interaction of polyvinylpyrrolidone with small cosolutes in aqueous and non aqueous media

The properties of dilute solutions of polyvinylpyrrolidone (PVP) in aqueous and non-aqueous solvents in the presence of small molecules are studied by measurements of intrinsic viscosity, [η]. The unperturbed dimensions are determined in pure solvents and in solvent mixtures. There are different unperturbed states, depending on the solvent and the solvent/cosolute mixture. These results are discussed on the basis of the nature of the side group interaction with the solvent and the cosolute. The role of the preferential adsorption of one of the cosolute on the polymer was considered. It would seem that the solvent plays an important role in the type of interaction.     

Studies on syntheses and permeabilities of special polymer membranes. 27. Concentration of poly(styrene sulphonic acid) in various aqueous solutions using poly(vinylidene fluoride) membranes

The permeation characteristics of poly(vinylidene fluoride) membranes in the separation and concentration of poly(styrene sulphonic acid), from various aqueous solutions were investigated under various conditions. The rejection of the polymer from its aqueous solution was high, because electrostatic repulsions between the charges along polymer chains cause chain extension. When a salt, such as sodium chloride, and sulphuric acid were added to the aqueous solution and the pH was changed, the configuration of the poly(styrene sulphonic acid) molecules changed significantly with the added amounts of salt. The permeation characteristics were influenced markedly by the conformational changes of polymer molecules and the viscosities of permeating liquids. The rejections were dependent on the conformational changes: the permeation rates were mainly governed by the viscosities. Poly(vinylidene fluoride) membranes had much superior resistance to acid, i.e. even when immersed in concentrated sulphuric acid for 7 days, the permeation characteristics did not change at all. The membranes were also effective for the concentration of poly(styrene sulphonic acid) and the removal of sulphuric acid from aqueous mixtures since the concentration of these solutes were optimum.     

Calculation of Viscosities of Liquid Mixtures Using Eyring’s Theory in Combination with Cubic Equations of State

1 INTRODUCTON The viscosity, particularly that of liquid mixtures is very important in engineering calculations involved in the process design for petroleum and other chemica industries. Since the successful development of a one-parameter equation for correlating the liquid vis cosity of nonpolar mixtures by Grunberg and Nissan[1] many other models have been proposed. Most of them are based on the corresponding state principle, the absolute rate theory of Eyring[2], or the free volume the…     

Weighted intrinsic viscosity relationships for polysaccharide mixtures in dilute aqueous solutions

The weighted intrinsic viscosities of polysaccharide mixtures in dilute aqueous solutions have been studied. The purpose of this investigation is to demonstrate that average intrinsic viscosities would scale with the weight fraction of the individual components for polysaccharide mixtures in 0.5N NaOH_(aq). The polysaccharides examined in this study were composed of polymers differing in their molecular weights, degree of branching, and bond linkages. Excellent agreement between theory and experiment was observed for the three different mixed polymer systems examined. This observation validates certain aspects of proposed theoretical treatments which employ this fundamental assumption and allows for further advances in experimental analytical developments of water-soluble polymer systems.     

均三甲苯/二异丁基甲醇混合溶剂黏度测定及关联

采用乌氏黏度仪,在常压和293.15～323.15 K温度范围内测定了均三甲苯与二异丁基甲醇混合溶剂以及两种纯溶剂的黏度,计算了不同温度和组成下混合溶剂的超额黏度。用Redlich-Kister方程对超额黏度进行了关联;用Andrade方程、UNIFA-VISCO模型以及Grunberg-Nissan模型对黏度进行了关联与预测。结果表明,混合溶剂的黏度随温度升高和均三甲苯含量增加而减小。超额黏度均为负值,且随均三甲苯含量增加呈U形变化,约在均三甲苯摩尔分数为0.3时达到最低。Grunberg-Nissan模型对黏度数据的关联和预测性最好,预测值与实测值的最大和平均相对偏差分别为12.96%和5.74%。     

An IR study on ion-specific and solvent-specific swelling of poly(N-vinyl-2-pyrrolidone) gel

Swelling degrees of poly(N-vinyl-2-pyrrolidone) (PVP) gel were measured in aqueous salt solutions and in water/organic solvent mixtures to find marked ion- and solvent-specificities. In order to investigate any correlation of those specificities with hydration or solvation of PVP, IR spectra band of the CO group was monitored by means of ATR method both for PVP gel and the relevant solution systems. Dependence of the peak frequency on the swelling ratio suggested that hydration of PVP carbonyl group in deswollen gel systems is different from that in the corresponding solution systems. In the solution systems, PVP carbonyl band showed a high-wavenumber shift for deswollen systems, which can be well correlated with changes in water proton charge through ionic hydration and with Gutmann's acceptor number of organic solvents. In the deswollen gel systems, the CO band showed a low-wavenumber shift, suggesting a strong hydration or doubly hydrated state. This unexpected behavior was interpreted by assuming an intermolecular hydrogen bond of two carbonyl groups intermediated by water molecules.     

Einführung in die Transportvorgänge in konzentrierten wäßrigen Elektrolytlösungen und Salzschmelzen

Introduction to transport phenomena in concentrated aqueous electrolyte solutions and molten salt mixtures . Up to this day there is no general theory of liquids. Since water-free molten salt mixtures are simpler in their structure than concentrated aqueous electrolyte solutions, it would be reasonable first to develop a theory for molten salts and then to apply this to aqueous electrolyte solutions by approximation. Such a theory does not yet exist. In this paper the system water + salt is therefore considered in the concentration range between pure water and pure salt in the liquid state. The phenomenological coefficients and friction coefficients of the different species of the system calculated from transport data are characteristic parameters for the entire concentration range which will probably offer possibilities for the analysis of transport phenomena, in close relation with the structure of the water + salt mixture. Common and essentially different properties, such as reference system and condition of electric neutrality, are discussed for concentrated aqueous electrolyte solutions and molten salt mixtures. The investigation of transport numbers from concentration cells with transference and the determination of the interdiffusion coefficients are illustrated for the system H₂O + CaCl₂ (highly concentrated electrolyte solution) and LiNO₃ + AgNO₃ (molten salt mixture). The phenomenological coefficients and the friction coefficients are calculated from the measured transport data.     

Mixed micelles of cationic surfactants and bile acid salts in aqueous media

Critical micelle concentrations of cetyltrimethylammonium-p-toluene sulfonate (CTAT) and cetylpyridinium chloride (CPC) with sodium cholate (NaC) and sodium deoxycholate (NaDC) were determined in aqueous solutions by surface tension measurements. Interaction parameters and mole fraction of the components in mixed micelles were estimated using Rubingh's theory. Strong interaction was observed for each mixed system, a common feature shown by anionic-cationic mixtures. Dramatic effects on the viscosities of these cationic surfactant-bile salt mixtures were seen, and were markedly dependent upon the counterion of the cationic surfactant and the nature of bile salts. Micelles are small and spherical for cationic surfactants in the presence of NaC. Micelle growth was seen for CPC in the presence of NaDC by an increase in viscosity, but a CTAT solution showed an opposite effect on addition of NaDC. Conductance results supported this view. Different behavior of the two bile salts is explained on the basis of their orientation in cationic micelles.     

Diffusion Coefficients ofl-Lysine Hydrochloride and l-Arginine Hydrochloride in Their Aqueous Solutions at 25℃

The diffusion coefficients** ofl-lysine hydrochloride andl-arginine hydrochloride in their aqueous solu- tions at 25℃ were determined by the metallic diaphragm cell method which is characterized by accuracy, promptness and convenience. Meanwhile, the densities and viscosities of the solutions were also determined. Based on all these data a semi-empirical model for correlating the diffusion coefficients of solid organic salts in their aqueous solutions at 25℃ was proposed. The fitting result of this model is comparatively satisfactory. Compared to a former model, Gordon Model, this model can avoid a number of difficulties and arduous work.     

Correlation and prediction of the viscosity of defined and undefined hydrocarbon liquids

A new method based on the effective carbon number is presented for the correlation and prediction of the viscosity of liquid hydrocarbons and hydrocarbon mixtures. It is proposed that the effective carbon number for the substance of interest be obtained from a single viscosity datum in the liquid range. The viscosity-temperature relationships of sixty-nine hydrocarbons, eleven defined hydrocarbon mixtures and eight crude oil fractions were studied in the present work. In general, calculated viscosities compared favorably with experimental data for all the systems studied. The calculated viscosities were also found to compare favorably with the results of the widely-used TRAPP method.     

Solution properties of ionic hydrophobically associating polyacrylamide with an arylalkyl group

Copolymers of acrylamide, 2‐acrylamide‐2‐methylpropanesulfate (AMPS), and hydrophobic monomer N‐arylalkylacrylamide (BAAM) were synthesized by free‐radical micellar copolymerization. The effects of the copolymer, BAAM, AMPS, and NaCl concentrations and the pH value on the apparent viscosity of the copolymers were studied. The solution viscosities increased sharply when the copolymer concentration was higher than the critical associating concentration. The apparent viscosities of aqueous solutions of poly(N‐arylalkylacrylamide‐co‐acrylamide‐co‐2‐acrylamide‐2‐methylpropanesulfate) (PBAMS) increased with increasing BAAM and AMPS concentrations. PBAMS exhibited good salt resistance. With increasing pH, the apparent viscosities first increased and then decreased. Dilute PBAMS solutions exhibited Newtonian behavior, whereas semidilute aqueous and salt solutions exhibited shear‐thickening behavior at a lower shear rate and pseudoplastic behavior at a higher rate. Upon the removal of shear, the aqueous solution viscosities recovered and became even greater than the original viscosity, but the salt solution viscosities could not recover instantaneously. The elastic properties of PBAMS solutions were more dominant than the viscous properties, and this suggested a significant buildup of a network structure. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 316–321, 2005     

Water Content of Organic Solvents and their Relationship to Extraction of Nitric and Acetic Acid from UREX+ Streams

This study investigates the equilibrium absorption of water in various solvents and solvent-mixtures being considered for the counter-current solvent extraction of acetic acid from improved Uranium Extraction (UREX+) process solutions. It then seeks to determine if there is any correlation between the equilibrium water content of these solvents and their equilibrium extraction of 0.25 M nitric and 0.025 M acetic acid. The UREX+ process is a proliferation resistant version of the Plutonium Uranium Extraction (PUREX) process. The solvents studied were n-Dodecane (nDD), 1,2 Dichloroethane (DCE), and Phenyltrifluoromethyl Sulfone (FS-13), and mixtures of these solvents with Tributyl Phosphate (TBP). After studying both pure water and acidified aqueous systems, it seems the water absorption mechanism is independent of the diluent used and remains constant with the addition of the 0.25 M nitric and 0.025 M acetic acid.