Studies of the Conformation of Polyelectrolytes and Excluded-Volume Effects on Them

聚电解质的构象及其排阻体积效应的研究

基本信息

批准号：
09450363
负责人：
NORISUYE Takashi
金额：
$ 8万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

The present study was undertaken to elucidate the effects of electrostatic interactions on chain stiffness (or conformation) and excluded-volume effect in naturally occurring and synthetic polyelectrolytes. The radii of gyration, intrinsic viscosities, and translational diffusion coefficients of sodium hyaluronate (HA), succinoglycan (Na salt), Na poly (styrenesulfonate) (NaPSS), and Na poly (isoprenesulfonate) (NaPI) in aqueous NaCl determined by static and dynamic light scattering, small-angle X-ray scattering, and viscometry were analyzed by the current theories for unperturbed wormlike chains combined with the quasi-two-parameter theory for excluded-volume effects. The analysis substantiated that for intrinsically flexible or weakly stiff polymers (HA, NaPSS, and NAPI), electrostatic stiffening and volume effects are responsible for the observed increases in molecular size with lowering ionic strength. The molecular weight dependence of each property was found to be explained almost quantitatively by the above-mentioned theories for uncharged polymers if the ionic strength is not lower than 0.01-0.05M. On the other hand, the chain dimensions of succinoglycan were almost independent of ionic strength above 0.05M because of the high stiffness comparable to that of double-stranded DNA. The data analysis strongly suggested that the ordered structure of this polysaccharide (stable below 40。・ be double-helical.

本研究的目的是阐明静电刚度（或组成）和自然发生的多电解质中链刚度（或组成）和排除体积效应的影响。陀螺仪（HA），琥珀酸酯（HA），琥珀酸酯（Na盐），Na Poly（Na poly（styrenenesulfonate）（NAPS）和Na poly（等肾上腺磺酸盐）（NAPI）在静态和动态散射中散布的散布量（NA），旋转，内在粘度的半径和翻译的差异系数（ha），琥珀酸酯（Na盐），Na Poly（Na poly（NA）和Na poly（Na photerrenes磺酸盐）（na poly（inaps））通过当前的不受干扰的虫状链的理论结合了排除体积效应的准参数理论。该分析证实，对于本质上的柔性或弱刚性聚合物（HA，NAPS和NAPI），静电僵硬和体积效应是导致观察到的分子大小的增加，而离子强度降低。如果离子强度不低于0.01-0.055m，则发现每个特性的分子量依赖性几乎是通过上述未加成聚合物的理论来定量解释的。另一方面，由于高刚度与双链DNA相当的高刚度，琥珀糖糖的链尺寸几乎独立于高于0.05m的离子强度。数据分析强烈表明该多糖的有序结构（稳定在40以下。