Evaluation of the Electrostatic Effect on Ionic Reactions in Charged Polyion Systems

带电聚离子系统中离子反应的静电效应评估

基本信息

批准号：
05804036
负责人：
MIYAJIMA Tohru
金额：
$ 1.28万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05804036/
关键词：
Polyelectrolytes Ion-Exchange Complexation equilibria Carboxymethyldextran Gel デキストラン硫酸

项目摘要

An electrostatic effect attributable to counterions being concentrated around the polymer skeleton makes the binding equilibria of polyion-counterions complicated. The objective of the present research project is to examine the applicability of a Gibbs-Donnan concept to evaluate the electrostatic effect in the binding equilibria of linear and cross-linked linear polyions (polyion gels). Dextran sulfate (DxS) and carboxymethyldextran (CmDx) have been used as examples of linear polyions, and sulfopropyl dextran gel and carboxymethyldextran gel have been usesd as examples of cross-linked linear polyion gels. Introduction of a volume term for the counterion concentrating region permits definition of the averaged concentrations of the ionic species in the vicinity of the polyion skeleton. Results of the counterion binding equilibrium analysis of DxS and CmDx revealed that both the Donnan potential term and the volume term for the counterion concentrating region can be expressed simply as a function of the linear charge separation of the polyion and the added salt concentration. The ionic atmosphere in the polyion domain is considered to correspond to a homogeneous concentrated electrolyte solution composed of fixed ions, counterions, and co-ions. By defining the standard state of each phase to be the same, valid insights with respect to the measured properties of the various species in the polyion domain are facilitated. Agreement of the values of the intrinsic binding constants of the monodentate complexes of CmDx and its gel analogs determined with this approach, with those of the corresponding metal complexes of their monomer analogs demonstrate the value of this approach. It has been proved by the present systematic work that the Gibbs-Donnan concept can be applied to the thermodynamic expression of the counterion binding equilibria of any polyions, irrespective of their shapes, appearances, and the nature of the fixed ions.

归因于聚合物骨骼周围的抗衡值的静电效应使得Polyion-Counterions的结合平衡变得复杂。本研究项目的目的是检查Gibbs-Donnan概念的适用性，以评估线性和交联线性Polyix（Polyion Gels）的结合平衡中的静电效应。硫酸葡萄酸盐（DXS）和羧甲基二克（CMDX）已被用作线性多元素的示例，硫丙基葡萄糖凝胶和羧甲基二十一凝胶已被用作交联线性聚校凝胶的示例。引入相反浓缩区域的体积项允许对波利奥骨架附近离子物种的平均浓度进行定义。 DXS和CMDX的反子结合平衡分析的结果表明，Donnan电位项和反子浓缩区域的体积项都可以简单地表示是Polyour的线性电荷分离和添加的盐浓度的函数。 Polyion结构域中的离子气氛被认为对应于由固定离子，柜台和CO-ION组成的均匀浓缩电解质溶液。通过将每个阶段的标准状态定义为相同的，就Polyion域中各种物种的测量特性而言，有效的见解得到了促进。用这种方法确定的CMDX单次结合复合物及其凝胶类似物的固有结合常数的值，其单体类似物的相应金属复合物的值证明了这种方法的值。目前的系统工作证明了吉布斯 - 唐南概念可以应用于任何多元素的反子结合平衡的热力学表达，无论其形状，外观和固定离子的性质如何。