Influence of alkali metal counterions on the charging behavior of poly(acrylic acid)
Influence of alkali metal counterions on the charging behavior of poly(acrylic acid)
复制标题
碱金属抗衡离子对聚丙烯酸带电行为的影响
DOI：
10.1016/j.polymer.2009.06.032
复制
发表时间：
2009
期刊：
影响因子：
4.6
通讯作者：
M. Borkovec
中科院分区：
文献类型：
--
作者：
A. Sadeghpour;Andrea Vaccaro;S. Rentsch;M. Borkovec
用精密电位滴定法研究了不同碱金属反离子存在下，聚丙烯酸(PAA)的荷电行为。充电行为可以用一种新的圆柱体-斯特恩模型来定量描述。该模型基于圆柱体几何中的泊松-玻尔兹曼方程和一个恒定的斯特恩电容。我们发现，随着碱金属离子质量的增加，圆柱体半径增大，斯特恩电容相应减小。未带电聚合物的本征电离常数随离子强度的增加而减小，与低分子质量的弱酸相似。
Charging of poly(acrylic acid) (PAA) in the presence of different alkali metal counterions was studied by precision potentiometric titration. The charging behavior can be described with a novel cylinder Stern model quantitatively. This model is based on the Poisson–Boltzmann equation in the cylinder geometry and a constant Stern capacitance. One finds an increasing cylinder radius with increasing mass of the alkali metal ion and a correspondingly decreasing Stern capacitance. The intrinsic ionization constants for the uncharged polymer are found to decrease with ionic strength, similarly to weak acids of low molecular mass.