基团贡献法确定简化空穴理论状态方程的分子参数

本文对作者开发的简化空穴理论状态方程的纯物质参数做了基团贡献处理，得到了１４个基团参数，可以比较好地预测正构烷烃、异构烷烃、环烷烃、芳香烃及部分聚合物的热力学性质。     

基于UNIFAC基团贡献法的计算机辅助分子设计

本文论述了一种基于UNIFAC基团贡献法的计算机辅助分子设计方法。该方法采用UNIFAC模型中的基团概念,借助计算机技术来设计合成分子。主要涉及基团的分类和表征、基团的预选和可行分子结构的合成,同时本文编制了相应的分子设计程序。     

基团贡献法分子设计研究的进展

利用基团贡献法可预测化合物的性质,还能用于化合物的计算机辅助分子设计(CAMD).本文论述了基于基团贡献法CAMD的基本原理,以及在溶剂和聚合物等领域分子设计的应用,对分子设计的计算方法也作了简单的介绍.随着绿色溶剂和新型聚合物材料需求的增加,基团贡献法CAMD将大有应用前景.     

高分子体系基团贡献法研究进展

介绍了高分子溶液中基团贡献活度系数模型、基团贡献状态方程、高分子密度计算的基团贡献法以及它们的最新进展。     

计算正常沸点下液体摩尔体积的基团贡献法

本文建立了一个能够计算各种液体在正常沸点下摩尔体积的基团贡献法。用110种液体加以检验,其计算值与实验值的平均相对误差约为±0.8％,小于目前已有的所有计算法。     

利用基团贡献法计算生物柴油体系临界性质参数

物性数据是进行化工研究、生产、设计和开发的基石,但因实验测量难度较大、实验成本较高以及新物质的数量快速增长等问题,目前物性数据不足仍是普遍存在的情况。本文利用Joback法和C-G法对生物柴油体系的临界参数和偏心因子进行了估算,估算结果表明:对于临界温度和临界压力的估算,Joback要比C-G估算的准确。C-G法对大多数物质的偏心因子的估算是比较精确的,但是对于含有多个醇羟基的物质,偏离较大。     

用改进的金属膜池法测定二元物系液相扩散系数

为进一步缩短液相扩散系数的测定时间,对传统膜池的结构和实验方法作了改进,测定时间缩短为以前金属膜池的一半,仅约1小时。实验测定了苯、乙苯、邻二甲苯、环己烷和环己酮分别与正庚烷所组成的二元物系在25℃的扩散系数,还测定了甲苯+正庚烷物系在20℃、25℃、30℃、35℃的扩散系数以初步考察温度的影响。由实验数据回归得到了各物系微分扩散系数随浓度变化的多项关联式的系数。对上述物系扩散系数的变化规律进行了讨论。     

聚合物浓溶液气平衡估算的基团贡献法

评价了用聚合物浓溶液气液平衡估算的９种基团贡献法的预测模型,即ＡＳＯＧ,ＵＮＩＱＵＡＣ,ＵＮＩＦＡＣ,ＵＮＩＦＡＣ－ＦＶ,Ｆ－Ｈ,Ｅｌｂｒｏ－ＦＶ,ＧＫ－ＦＶ,ＧＣ－ＦｌｏｒｙＥｏＳ和ＧＣＬＦ ＥｏＳ的预测能力,建议使用ＵＮＩＦＡＣ－ＦＶ,Ｅｌｂｒｏ－ＦＶ,ＧＫ－ＦＶ,ＧＣ－ＦｌｏｒｙＥｏＳ（有待简化）４个模型来预测聚合物浓溶液的气液平衡。并展望了其今后的发展趋势。     

聚合物浓溶液气液平衡估算的基团贡献法

评价了用聚合物浓溶液气液平衡估算的９种基团贡献法的预测模型,即ＡＳＯＧ,ＵＮＩＱＵＡＣ,ＵＮＩＦＡＣ,ＵＮＩＦＡＣ－ＦＶ,Ｆ－Ｈ,Ｅｌｂｒｏ－ＦＶ,ＧＫ－ＦＶ,ＧＣ－ＦｌｏｒｙＥｏＳ和ＧＣＬＦＥｏＳ的预测能力,建议使用ＵＮＩＦＡＣ－ＦＶ,Ｅｌｂｒｏ－ＦＶ,ＧＫ－ＦＶ,ＧＣ－ＦｌｏｒｙＥｏＳ（有待简化）４个模型来预测聚合物浓溶液的气液平衡。并展望了其今后的发展趋势。     

从系统工程视角试论基于基团贡献法的树脂基体的分子设计

从系统工程的观点,提出了基于基团贡献法的树脂基体的计算机辅助分子设计的框架轮廓,以图促进潜在地作为传统树脂基体研发方法的有效替代或者至少是有益的补充的树脂基体的计算机辅助分子设计方法的发展。     

Group contribution methods for the prediction of thermophysical and transport properties of ionic liquids

Thermophysical and transport properties of ionic liquids are required for the design of processes and products. Yet the experimental data available are scarce and often contradictory. Based on experimental data collected from the literature, group contribution methods were developed for the estimation of viscosity, electrical conductivity, thermal conductivity, refractive index, isobaric expansivity, and isothermal compressibility, of various families of ionic liquids. Using the Stokes–Einstein relation a correlation for the self‐diffusion coefficients with the viscosity is also proposed. The results of the proposed models show average absolute relative deviations generally of the same order of the experimental accuracy of the data. They are easy to use and can provide predictions of property values for ionic liquids never previously studied. The group contribution basis of these models will allow them to be extended to new groups of cations and anions as further data became available. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

基团贡献法估算物性的进展

本文简述了基团贡献法的原理及其在基础物性估算中的应用，评述了基团贡献法的发展趋势。     

双阳离子型离子液体[C3(MIM)2][PF6]2的热容测定及估算

利用差示扫描热量计(DSC)测定了双阳离子型离子液体1,1′-(丙烷-1,3-二基)-双(3-甲基-1H-咪唑鎓-1-基)双六氟磷酸盐([C3(MIM)2][PF6]2)在293.15-543.15 K温区内的摩尔热容.实验结果表明:在293.15-403.15 K和433.15-543.15 K温区内,该化合物无相变...     

Fluorescence measurements of the diffusion coefficient for butylated hydroxyanisole in low-density polyethylene

Measurement of the diffusion coefficient (D) of butylated hydroxyanisole (BHA) in low density polyethylene at 31°C was made by two techniques. (1) Measurement of diffusion rate in the absence of solvent was made by use of a film stack with BHA-loaded discs on top and bottom. After a given diffusion time, the films were separated and the BHA extracted from the films into 1 -propanol. The fluorescence of the solutions provided values of BHA concentration as a function of film position in the stack, from which the value 3.4 (SD 0.3) × 10^?9 cm² s^?1 for D was calculated. (2) Fluorescence monitoring, under oxygen free conditions, was used to measure rate of BHA extraction from a film into 1 -propanol at 31°C, and gave the value 3.8 × 10^?9 cm² s^?1 for D which agrees well with the value determined by measurement in the absence of solvent.     

脂肪酸在甲基丙烯酸异丁酯凝胶中扩散系数的估测

采用分散质分子染色、跟踪手段,对游离脂肪酸分子在甲基丙烯酸异丁酯高分子凝胶体系中有效扩散系数进行测定和估算,实验测得有效扩散系数为10-11 m2/s数量级范围,处于估测范围之内。同时对比了分散质分子在纯液相中的自由扩散系数,并分析了凝胶体系中脂肪酸分子的扩散机制。结果表明:利用染色、跟踪定量法对大分子分散介质在凝胶体系中扩散行为的研究和有效扩散系数的估测具有可行性。     

Prediction of the effective diffusion coefficient in random porous media using the finite element method

A finite-element-based method is presented for evaluating the effective gas diffusion coefficient of porous solids. Using this method, the 3-D micro-scale geometries of the porous solids are constructed under the ANSYS platform by the parametric code; the relation between effective gas diffusivity and micro-scale features of random-distributed porous solids is established. The results show that in random-distributed pore media, there is a percolation threshold ε _p, and this percolation threshold decreases with increasing coordination number of the pore network. The relationship between the effective diffusivity and porosity is strongly nonlinear when the porosity, ε, is less than a certain value ε _L ; for ε > ε _L , the relationship becomes quasi-linear. This dividing point ε _L decreases with increasing coordination number. The larger the coordination number of the pore network, the higher the effective gas diffusivity. Based on the simulation results and observations, a formula relating the effective diffusion coefficient with porosity is proposed.     

Gamma-Ray method for measuring liquid expansion coefficient at high temperatures and pressures

Expandable vessels were designed to measure the density and thermal expansion coefficients of liquid at elevated temperatures and pressures by the gamma-ray attenuation method. Light Arabian vacuum bottoms was tested from 70°C to 300°C at 13.8 MPa. Results agree well with literature data.     

Comparison of electrochemical methods for triiodide diffusion coefficient measurements and observation of non-Stokesian diffusion behaviour in binary mixtures of two ionic liquids

Results of diffusion coefficient measurements of triiodide in a mixture of two ionic liquids (1-methyl-3-propylimidazolium iodide and 1-butyl-3-methylimidazolium tetrafluoroborate) at 25 °C are described in this paper. Four electrochemical methods for measuring diffusion coefficients of triiodide were evaluated for their reliability and performance, including impedance spectroscopy and polarization measurements at thin layer cells as well as cyclic voltammetry and chronoamperometry at microelectrodes of different radii. Viscosities of the blends were measured to investigate the transport behaviour of triiodide ions used in Grätzel-type dye-sensitized solar cells.     

The modelling and experimental study on molecular diffusion coefficient of CO2 in N-methyl pyrolidone

In this study, batchwise absorption of CO₂ in N-methyl pyrolidone (NMP) was experimentally performed at different conditions using pressure decay method, and as a result, the equilibrium data, Henry’s law constants, and kinetic data were reported. It was shown that solubility and diffusivity are two important factors affecting the kinetic behaviour of the system. This absorption system was mathematically modelled using Fick’s second law accompanied by a time-dependent boundary condition. Thus, the diffusion coefficients of CO₂ in NMP were calculated under different operating conditions by means of the experimental kinetic data. Furthermore, the influence of temperature and pressure on the diffusion coefficient of CO₂ in NMP was analysed.     

人工神经网络基团键贡献法预测烷烃闪点

建立了一个基于人工神经网络方法的基团键贡献模型,用于预测烷烃闪点。该模型既考虑了分子中基团的特性,又考虑了基团之间的连接性(化学键)。以16种烷烃基团键作为神经网络的输入参数,研究了44种烷烃的闪点与分子结构之间的相关性。结果表明,闪点预测值与实验值符合良好,绝对平均绝对误差6.0 K,绝对平均相对误差2.15%,优于传统基团贡献法所得结果。该方法的提出不仅揭示了烷烃闪点与分子结构之间的定量关系,而且为工程上提供了一种预测有机物闪点的新的有效方法。