随机共聚高分子凝胶溶胀和体积相变行为的分子热力学模型

基于随机共聚高分子溶液的格子模型,建立了一个可以描述温度和pH双重响应的随机共聚高分子凝胶溶胀行为的分子热力学模型。该模型考虑了溶剂与不同高分子的混合、高分子网络的弹性以及包含小分子离子在凝胶内外分布的Donnan平衡和聚合物网络上的大分子离子及其反离子之间的静电相互作用的离子影响对化学势的贡献。与其他模型不同的是,该模型还考虑了高分子的组成f。该模型有两类可调的模型参数,一类是溶剂与不同高分子网络之间的相互作用能参数ε槇ij,另一类是高分子网络自身的尺寸参数Mc。研究结果表明,该分子热力学模型只需较少的模型参数就可较好地描述温度和pH双重敏感的随机共聚高分子凝胶的溶胀行为。     

共聚高分子溶液的分子热力学模型

引　言共聚高分子因具有很多均聚高分子所没有的性质而受到人们的广泛关注 .但文献中发表的有关共聚高分子系统的汽液相平衡 (ＶＬＥ)数据较少 ,能够用于关联或预测的分子热力学模型也不多 .最常用的模型是基于密堆积格子模型的Ｆｌｏｒｙ -Ｈｕｇｇｉｎｓ理论及其改进模型 .近年来 ,在严格的统计力学理论基础上建立非格子的链状流体状态方程引起了人们更大的兴趣 ,并相继建立了一些具有实用价值的状态方程[1～ 5] .对于共聚高分子系统 ,Ｈｉｎｏ等人[6 ]建立了实用的状态方程 ,Ｂａｎａｓｚａｋ等人[7] 在热力学微扰理论 (ＴＰＴ1)的基础上…     

乙腈对LLDPE催化剂活性影响的考察

用ＢＰＺ－Ｎ催化剂研究了共聚单体１－丁烯中乙腈含量分别为０，０．０００３５％（Ｖ），０．０００６９％（Ｖ），０．００１２３％（Ｖ），０．００１７６％（Ｖ）时对乙烯与１－丁烯共聚活性的影响。结果表明：当乙腈含量在０．０００３５％（Ｖ）以上时，随乙腈含量的增加，催化剂活性呈直线下降趋势，当达到０．００１７６％（Ｖ）时，活性保有率已不足不含乙腈时的５０％。     

《高等化工热力学》教材介绍

《高等化工热力学》一书既是一本研究生教材,也是一本分子热力学专著。教材深入浅出地阐述了统计热力学的基本原理,同时以较大篇幅详细介绍了液体状态方程,以及电解质溶液、高分子溶液和生物大分子溶液的分子热力学模型、前沿进展和工程应用。     

水溶性淬火剂用共聚醚的合成研究

研究了以ＫＯＨ为催化剂，二元或三元醇为起始剂，采用阴离子开环聚合合成淬火剂用共聚醚。结果表明：产物的分子量随起始剂和杂质量的减少而增加；聚醚的组成取决于投料比；其浊点随环氧乙烷含量增加而升高。起始剂用量≤８．０ｍｍｏｌＯＨ／１００ｇ单体；反应温度以１０５±５℃为宜；单体水分含量＜０．１％，醛含量＜０．１７％，环氧乙烷含量为８０±３ｍｏｌ％，合成的共聚醚分子量可大于１．０×１０４。     

高分子分子设计与PMMA改性

以高分子分子设计理论为指导，以PMMA为基材，在大分子链中引进甲基丙烯酸钆及其他单体，经本体共聚制得改性的PMMA．既可保留原有的某些性能，又可增添所期望的新功能，有望成为具有特殊功能的透明材料。     

复杂材料的微相分离和结构演变

共聚高分子和表面活性剂系统常常能够形成不同尺度的复杂结构,在材料和生物技术领域具有广泛的用途.这种结构及其形成过程与自然界中大量存在的斑图及其演化过程具有非常类似的机理,受到不同学科研究者的广泛关注.在高分子系统的分子热力学、微相分离及结构演变过程领域已经开展了大量的研究工作,已成为凝聚态物理、高分子物理、统计力学理论和计算机模拟的热点之一.在分子尺度上,基于格子和自由空间的分子热力学模型、计算机分子模拟方法可以用于描述高分子系统的相平衡和分子的聚集形态.在介观尺度上,时间相关的Ginzberg-Landau理论、元胞动力学方法等可以有效地研究微相分离结构的演变过程及其受外场的影响.而耗散粒子动力学模拟则可以将分子尺度和介观尺度的研究结合起来,是一种跨尺度的研究方法.多尺度研究方法的发展将成为今后研究的重点.本文总结了该领域的某些研究进展.     

链状流体的分子热力学模型(Ⅰ)──纯物质

实际链状流体的分子热力学模型表示为参考流体（硬球链流体）的贡献与一微扰项之和.作者先前建立的硬球链流体的状态方程用于计算参考流体的性质，用Alder等人对方阱流体的计算机模拟结果计算微扰项的贡献，从而建立了实际链状纯流体的分子热力学模型.该模型具有非常简单的形式，用三个与温度无关的分子参数（分子的链数，链节的直径和链节间的方阱位能阱深）可以较好地关联从球形小分子到链状高分子、分子间没有氢键作用的流体的饱和蒸汽压、饱和液体体积和pVT关系     

锦纶6切片萃取装置生产工艺探讨

介绍了从Ｉｎｖｅｎｔａ公司引进的锦纶６切片萃取装置的生产过程，分析了萃取温度、水浴比及萃取塔上段水溶液中低分子物浓度等对切片中低分子物含量的影响。指出，要降低切片中低分子物含量，必须选择合适的萃取温度，控制水浴比在（１．２０～１．４０）∶１．０之内，同时控制萃取塔上段水溶液中低分子物浓度为６．０％～８．０％。     

共缩聚反应中链段序列长度调控的分子模拟研究

利用分子模拟研究了共缩聚反应得到的高分子链上的嵌段长度分布。通过控制参加反应的两种组分的浓度比和共聚单体的反应活性,可得到与理论值差别很大的序列分布。有助于合成嵌段长度可控的共聚高分子。     

SIMPLIFIED HARD-SPHERE AND HARD-SPHERE CHAIN EQUATIONS OF STATE FOR ENGINEERING APPLICATIONS

A simple hard-sphere equation of state is proposed. This hard-sphere equation is a ratio of second-order polynomials that meets the ideal gas and close-packed density limits. It predicts the compressibility of hard-sphere fluids at low and medium densities to within a degree of quality similar to the widely used Carnahan-Starling equation. In addition, the proposed equation performs better at high densities, particularly near the close-packed density. An expression is also derived to relate the site-site correlation function at contact for hard dimers with the site-site correlation function at contact for hard spheres. With this relationship, the thermodynamic perturbation-dimer theory (TPT-D) of hard-sphere chains is simplified. The new theory performs comparably with the TPT-D when the compressibility factors of hard-sphere chain fluids containing up to 201-mer are predicted, however, it has the advantages of both simplicity and accuracy. From a practical perspective, this theory can be used to construct equations of state for polymer solutions or fluid systems containing short- and long-chain molecules.     

SIMPLIFIED HARD-SPHERE AND HARD-SPHERE CHAIN EQUATIONS OF STATE FOR ENGINEERING APPLICATIONS

A simple hard-sphere equation of state is proposed. This hard-sphere equation is a ratio of second-order polynomials that meets the ideal gas and close-packed density limits. It predicts the compressibility of hard-sphere fluids at low and medium densities to within a degree of quality similar to the widely used Carnahan-Starling equation. In addition, the proposed equation performs better at high densities, particularly near the close-packed density. An expression is also derived to relate the site-site correlation function at contact for hard dimers with the site-site correlation function at contact for hard spheres. With this relationship, the thermodynamic perturbation-dimer theory (TPT-D) of hard-sphere chains is simplified. The new theory performs comparably with the TPT-D when the compressibility factors of hard-sphere chain fluids containing up to 201-mer are predicted, however, it has the advantages of both simplicity and accuracy. From a practical perspective, this theory can be used to construct equations of state for polymer solutions or fluid systems containing short- and long-chain molecules.     

A CUBIC EQUATION OF STATE BASED ON A SIMPLIFIED HARD-CORE MODEL

The Redlich-Kwong (RK) equation of state introduced in 1949 has been considered the most accurate two-constant-parameter cubic equation of state. The other cubic equations which are more accurate than the RK equation contain either three, or more, parameters and/or their parameters are temperature- dependent. A New two-constant-parameter cubic equation of state, $ is introduced using a simplified molecular theory of hard-sphere fluids for its repulsive term. This two-constant-parameter cubic equation of state appreciably increases the accuracy of thermodynamic property predictions and phase equilibria of pure fluids and flluid mixtures over the equations of this category.     

硬球链流体在平板和硬球表面分布的密度泛函理论

采用Yethiraj和Woodward的密度泛函理论方法,结合胡英和刘洪来等发展的硬球链流体状态方程,得到了自由连接硬球链流体在平板狭缝中和球形固体颗粒表面附近的密度分布表达式,并计算了在两平行壁所组成的狭缝中和直径大小不同的球形固体颗粒周围硬球链分子的链节密度分布.理论计算结果与作者采用Dickman 和Hall 的方法进行Monte Carlo计算机模拟结果非常吻合.颗粒直径对链状分子的密度分布有一定的影响,随着固体颗粒直径的增加,靠近颗粒表面附近的链节密度降低.     

环状和支链硬球链流体的状态方程

以单体缔合的统计力学理论为基础，建立了链状分子亥氏孙数和状态方程和空们相关函数的关系，并应用于环 状和支链硬球链流体。对这两类流体压缩因子的预测结果与计算机模型值相吻合。     

高压下长链分子的自扩散系数研究

在Lennard-Jones流体自扩散系数方程的基础上,结合链状硬球流体自扩散系数的分子模拟数据,提出了链状Lennard-Jones流体的自扩散系数方程。将所提出的方程应用于计算长链烷烃和硅油在0.1-600MPa下的自扩散系数,其平均相对偏差在10％以内,计算结果优于自扩散系数的粗糙Lennard-Jones模型。     

Phase equilibria of associating fluid mixtures using the perturbed-hard-sphere-chain equation of state combined with the association model

For developing the equation of state which can be applicable to associating fluids, the Perturbed-Hard-Sphere-Chain-Association (PHSC-AS) equation of state is proposed by incorporating the association term of the SAFT model into the PHSC equation of state which has been widely used to describe phase equilibria for the fluid system containing a large molecule such as polymer. In this work, two different types of PHSC models have been examined. One is the original model proposed by Song et al., and the other is the modified model by Kim and Bae whose chain term was replaced with that of the SAFT model. As a result, two types of PHSC-AS models are obtained, and applied to the calculation of phase equilibria for the binary system containing a self-associating compound such as alcohol, amine and carboxylic acid, etc. The calculated results of vapour-liquid equilibria are in good agreement with the experimental data. The proposed models (PHSC-AS) are also compared to the PC-SAFT model.     

EQUATIONS OF STATE FOR HARD-SPHERE CHAIN FLUIDS AND SQUARE-WELL CHAIN FLUIDS

Based on the statistical theory for chemical association,equations of state for hard-spherechain fluids(HSCFs)and square-well chain fluids(SWCFs)can be derived through the n-particlecavity correlation function(CCF)of the corresponding reference system,where n is the chain lengthor the number of segments of a chain molecule.The reference system is a fluid composed of only cor-responding monomers.In this work,the n-particle CCF is approximated by a product of effectivetwo-particle CCFs which accounts for correlations in nearest-neighbour and next-to-nearest-neighboursegment pairs.The CCFs for SWCFs may be expressed by a product of the corresponding functionfor HSCFs and a perturbation term originated from the square-well attractive potential.All these ef-fective two-particle CCFs and perturbation terms are density dependent.The dependence is determinedmainly by using computer-simulation results.The obtained equations can excellently describecompressibility factors and second Virial coefficients for HSCFs     

基团贡献状态方程的开发与热力学模型参数的理论预测

热力学模型是研究流体相行为和热力学性质的重要工具。理论模型的有效应用离不开模型参数的确定。为赋予热力学模型的预测功能，目前的策略一是建立基团贡献(GC)状态方程(EOS)，二是探索热力学模型参数的理论预测方法。围绕先前开发的变阱宽方阱链流体状态方程(SWCF-VR)，采用基团贡献法思路获得了不同基团对模型参数的贡献值，建立了GC-SWCF方程，证实GC-SWCF方程能满意预测纯物质的密度。进一步将似导体屏蔽模型(COSMO)与SWCF结合，基于COSMO方法获得了192种有机化合物的SWCF方程的模型参数，这是一种不依赖实验数据确定模型参数的理论方法。发现COSMO+SWCF能较好地预测纯物质的密度。引入一个与温度无关的二元交互作用可调参数后，GC-SWCF与COSMO+SWCF都可应用于二元混合物密度与气液相平衡的计算中。     

一个新的基团贡献型状态方程——GC-MCSPT方程

将超额Gibbs函数模型与修正的硬球三参数状态方程(MCSPT方程)相结合,导出由基团贡献模型定义的状态方程参数混合规则.直接利用低温下的基团贡献模型参数,如UNIFAC模型、修正的UNIFAC模型(简称MUNIFAC)的交互作用参数,分别预测了二元强极性物系的低压和高压相平衡以及三元强极性物系的汽液相平衡.结果表明,新模型具有广泛的预测能力和满意的预测精度.