甲酰胺溶剂中溶质间的过量Gibbs自由能相互作用参数

利用气液色谱方法测定了２９８．１５Ｋ时若干非电解质溶质在甲酰胺－乙酰胺、甲酰胺－尿素、甲酰胺－高氯酸钠固定液中的保留参数，采用ＭｃＭｉｌａａｎ－Ｍａｙｅｒ理论，将溶液热力学过量性质与溶液中粒子的对相互作用，参相互作用参数相联系，利用热力学方法求得了溶质的保留参数与Ｇｉｂｌｓ自由能相互作用参数的关系，并就溶质－溶质间的相互作用及溶剂性质的影响进行了讨论。     

应用反气相色谱法研究高分子-溶剂相互作用

应用反气相色谱法研究了聚乙二醇和若干溶剂的相互作用。实验表明以表面处理多孔硅胶为担体,为获得准确的保留体积,需考虑作固定相在担体上涂布量外推。据此计算出相互作用参数X和 ,可和静态蒸汽吸附法或混合体积测定等所得数据相比,并反映了聚乙二醇和溶剂相互作用的某些特点。     

聚合物-溶剂的相互作用参数

在溶解度参数理论中,聚合物-溶剂的相互作用参数X_1计算式为: X_1=V_1/RT(δ_1-δ_2)~2+β (1)式中V_1为溶剂的摩尔体积,δ_1和δ_2分别为溶剂和聚合物的溶解度参数。经验常数β是作为对Flory组合熵的改进而计入X_1中的。     

液-液溶解度法与气-液色谱法研究溶剂-溶剂的相互作用

测量了角鲨烷(B)+邻苯二甲酸二丁酯(C)的溶解度相图, 应用HSFH二元系公式推算得相互作用参数Abc; 用气-液色谱测量了若干正构烷烃、环烷烃用作探测溶质(A)在(B+C)混合溶剂中的无限稀活度系数, 应用HSFH三元系公式推算得相互作用参数Abc, 两者符合热力学一致性。     

溶剂化热力学的理论研究(Ⅴ)——含水混合溶剂中AgCl、AgBrO3溶度积的理论计算

本文以AgCl、AgBrO₃在一系列浓度的MeOH-H₂O、EtOH-H₂O、PrOH-H₂O、Me₂CO-H₂O及DMSO-H₂O混合溶剂中的离解平衡为研究对象,从离子溶剂化能的角度计算了这些难溶盐的溶度积,计算结果与文献值吻合较好.     

溶剂-导体界面电子转移溶剂重组能的球-界面模型

在连续介质理论基础上, 根据热力学基本原理, 用一个外加电场Eex将非平衡态2[Enon2, Dnon2]变成约束平衡态[E*2, D*2], 推导出了正确普适的溶剂重组能公式. 基于球-界面近似, 推导出了正确的溶剂-导体界面电子转移溶剂重组能公式. 和Marcus的公式相比, 本文的结果多了(εs-εop)/(εop(εs-1))因子. 对极性溶剂, 预测的溶剂重组能约为Marcus模型所得结果的一半. 以C343(Coumarin 343)-TiO2体系为算例, 计算了溶剂重组能并与实验值进行了比较.     

二价离子溶剂化自由能的计算—玻恩方程的应用

离子溶剂化自由能是一个很重要的热力学参数,求得溶剂化自由能后,不仅可以了解离子溶剂化的性质,而且由此还可以计算其它热力学函数。由于单个离子不能独立存在,所以不能由实验直接测得单个离子的溶剂化自由能。1920年,玻恩根据静电模型,提出计算单个离子溶剂化自由能的公式如下:     

四苯硼钾由单-到不同混合溶剂的迁移自由能

KBPh4作为一种典型的大阴离子电解质 ,在研究与计算大分子电解质的迁移热力学性质中起着重要的作用 .讨论大分子电解质与不同溶剂间的作用 ,还可以为萃取、色谱及表面活性剂的研究提供理论依据 .一些文献及我们前文曾对四苯硼盐由水到一些纯溶剂 [1,2]及从水到某些水-有机混合溶剂中的标准迁移自由能进行了研究 [3],但对四苯硼盐在有机-有机混合溶剂中的研究报导极少 .本文对 KBPh4由水到水-异丙醇和由甲醇到甲醇-异丙醇混合溶剂的标准迁移自由能进行了研究和探讨 .1实验部分 1.1实验仪器及方法 　　用 CS501型超级恒温槽恒温 ;用 WF…     

Evaluation of the polymer-solvent interaction parameter χ for the system cured styrene butadiene rubber and toluene

One of the most popular cured rubbers used in industrial applications is styrene butadiene rubber (SBR) and frequently its network structure is studied by means of swelling techniques in solvent. Normally, toluene is used as solvent in this test. In order to estimate the crosslink density from the equilibrium volume fraction of rubber in the swollen state, the correct evaluation of the Flory-Huggins interaction parameter χ is necessary. This work covers the swelling behavior of cured SBR in toluene. The rubber was vulcanized with different amounts sulfur and accelerator at 433 K in order to obtain several network structures and crosslink densities. Network characterisations of the compounds were made by swelling measurements in the frame of the Flory-Rehner relationship using the molecular weight of the network chain between chemical crosslinks obtained previously by mechanical tests. A relationship between χ and v_r, the polymer volume fraction at equilibrium (maximum) degree of swelling, was established for the cured SBR/toluene system. It was found that χ is not a constant but depends on the crosslink density in the sample. The types of crosslinks in these samples where estimated applying this function to the swelling behavior of the compounds previously treated with the thiol probe method.     

Rationalizing the meaning of coefficients in Flory-Huggins approach to polymer-solvent interactions

The Flory-Huggins interaction parameter for a polymer solution can be represented as the product of two functions, which separately take into account the effects of the polymer volume fraction and temperature. The latter factor contains three constants, usually viewed as best-fit coefficients. They are expressed in terms of two thermodynamic quantities, namely, the excess partial molar heat capacity of the solution and a reference temperature, thus allowing to guess their physical meaning. The formulae so obtained were tested with satisfactory results for two solutions of polystyrene in acetone and for two polymer blends (PC/PMMA and PS/PVME.) Furthermore, an attempt was made to calculate the above-mentioned reference temperature from data referring to the phases in solution.     

四元系溶液中溶质间的Gibbs自由能相互作用参数的研究

用气液色谱法测定２９８．１５Ｋ下，有机溶质在尿素＋高氯酸钠＋甲酰胺固定液中的保留参数，用ＭｃＭｉｌｌａｎ－Ｍａｙｅｒ理论，将溶液的势力学过量性质与溶液中粒子间的对相互作用、三相互作用参数相联系，用热力学方法求得该四元体系中溶质的气液色谱保留参数与Ｇｉｂｂｓ自由能相互作用参数的联系，并就溶质间的相互作用及混合溶剂性质的影响进行了讨论。     

Determination of Polymer Compatibility by Viscometric Measurements on Ternary Solutions of the Two Polymers

Results on the intrinsic viscosity [η] are reported for the system solvent(1)/polymer(2)/polymer(3) in which the solvent was benzene, polymer(2) was polystyrene (PS), and polymer(3) was poly(dimethylsiloxane) PDMS. The values of [η] were then used to determine the likely compatibility of polymer blends of PS and PDMS. Initial focus was on the traditional interaction parameter b ₂₃ ⁽¹⁾ used by several authors to predict compatibilities, it but depends on the molar mass, weight fractions, and concentrations of each polymer. A new interaction parameter b ₂₃ ⁽²⁾ that is independent of polymer(3) concentration and molar mass was evaluated for determinations of polymer compatibility.     

Anomalous solubility parameter and probe dependency of polymer-polymer interaction parameter in inverse gas chromatography

Inverse gas chromatography (IGC) has been widely used to measure the Flory-Huggins interaction parameters, χ, between two polymers. For over two decades studies have shown the polymer-polymer interaction parameter to be probe dependent. This study found that the solubility parameters of miscible polymer blends measured by IGC were lower than the volume average values of the components. This led to the conclusion that when specific interactions occur between two polymers the probes have less probability to contact the functional groups of the polymers, leading to a lower apparent solubility parameter. Using the solubility parameter model this deviation was shown to cause the probe dependency. Two methods were proposed to test the miscibility. One was to examine the deviation of the specific retention volume from the weight average rule. The other was to plot ?₂?₃RT(χ₂₃/V₂) vs. the solubility parameters of probes. For miscible blends a linear trend with negative slope was observed. The slope was proportional to the deviation of solubility parameter of the polymer mixtures from the volume average, which could be used as a measurement for miscibility.     

计算高聚物增塑体系混合自由能新方法

高聚物增塑体系混合自由能与浓度关系 ΔGm=f(ω1) ,不仅反映了增塑体系热力学稳定性好坏 ,而且可以预测溶液各组分间的作用能力 [1,2 ] .通过实验可直接得到增塑体系混合自由能的相关数据 ,其中包括偏蒸气压值测量法、渗透压法、反相气相色谱法及小角 X射线散射法等[3～ 8] .这些方法可以测量增塑体系挥发性组分的偏摩尔化学位值 ,利用下面公式计算Δμ1/RT =ln(p1/p1,S)式中 p1,p1,S是某温度下增塑体系增塑剂的偏蒸气压值和纯增塑剂的饱和蒸气压 .1　现有的高聚物混合体系自由能 ηGm计算方法对于低分子溶液体系各组分的偏摩尔化学位Δ…     

Micellisation behaviour of mixtures of sodium dodecylsulphate and sodium lauroylsarcosinate in water

The critical micelle concentrations of binary mixtures of sodium dodecylsulphate (SDS) and sodium lauroylsarcosinate (SLAS) have been determined in water by conductivity measurements at different mole fractions for each of the components. The critical micelle concentrations were slightly lower than that predicted from ideal mixing theory indicating positive synergistic interactions in mixed micelle formation. The results of the mixed systems were analysed using the Regular Solution Theory and the approach based on the Gibbs–Duhem equation which allowed for the determination of the composition of the mixed micelle, the activity coefficients and the pair-wise molecular interaction parameter β. The β values were all negative at all mole fractions investigated, showing a slight deviation from ideality, with an average value of –0.27. The excess free energy of the mixed systems was also calculated and the values were all negative for the mixed systems studied, an indication that the mixed micelles are thermodynamically stable relative to the individual component. This thermodynamic parameter also exhibits symmetrical behaviour with respect to micellar composition suggestive of a regular solution behaviour of the mixed surfactant system.     

Determination of pair interaction parameters for multicomponent polymer blends

Pair interaction parameters for multicomponent polymer blends were found to be determined by analyzing the sorption isotherms of common solvent.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2494–2496, November, 2004.     

Thermodynamic analysis on the cononsolvency of poly (vinyl alcohol) in water–DMSO mixtures through the ternary interaction parameter

Isothermal phase diagrams for the semicrystalline poly (vinyl alcohol) (PVA) in solutions composed of water and dimethylsulfoxide (DMSO) was studied at 25 °C. From the observed phase behavior, PVA was soluble in either water or DMSO individually but crystallization-induced gelation and liquid–liquid demixing were observed in water–DMSO mixtures. Flory–Huggins formalism including three binary interaction parameters and one ternary interaction parameter was used to study the phenomenon of the cononsolvency, i.e. the formation of nonsolvents by mixing two solvents. The equilibrium crystallization line in the DMSO-rich region and the total calculated binodals agreed well with the measured results when a composition-dependent ternary interaction parameter was included into calculations. In contrast, calculations yielded crystallization-induced gelation in the water-rich region, but experiments indicated that PVA remained well dissolved even 1 year after preparation. The discrepancy was explained by the temperature-induced changes in the relative interaction between water and PVA. In addition, the role of the ternary interaction parameter in the cononsolvent ternary polymer systems was discussed. It was found the contribution of the ternary interaction parameter in the cononsolvent system under study is to decline the degree of the cononsolvency. The driving force for cononsolvency is the strong interaction between water and DMSO to form the stable DMSO hydrate to exclude PVA segments in the vicinity of the hydrate.