Ion Exchange and Protonation Equilibria of an Amphoteric Ion-exchange Resin in the Presence of Simple Salt
Ion Exchange and Protonation Equilibria of an Amphoteric Ion-exchange Resin in the Presence of Simple Salt
复制标题
简单盐存在下两性离子交换树脂的离子交换和质子化平衡
DOI：
10.2116/analsci.24.1123
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发表时间：
2008
影响因子：
1.6
通讯作者：
Junko Konaka
中科院分区：
文献类型：
--
作者：
Y. Miyazaki;H. Qu;Junko Konaka
本文研究了一种两性离子交换树脂的离子交换和质子化平衡，研究了简单盐对该树脂的离子交换和质子化平衡的影响。用~(23)Na核磁共振谱测定了两性离子交换树脂与不同钠盐溶液平衡时的离子物种浓度。对于NaClO4体系，树脂相中钠离子浓度与平衡溶液中钠离子浓度之比大于1，且随盐浓度的降低而增大。与普通阳离子交换树脂不同，两性离子交换树脂对Mg~(2+)和Ca~(2+)的离子交换行为明显依赖于盐的种类：在氯化钠体系中的分配系数与盐浓度无关，而在NaClO_4体系中的对数D与对数[Na~(++)]呈线性关系，斜率既不为-2也不为0。与NaClO4溶液平衡时，树脂官能团中羧酸盐的表观质子化常数大于与NaClO4溶液平衡时的表观质子化常数。根据核磁共振方法估算的树脂相中盐浓度的信息，阐明了两性离子交换树脂的离子交换和质子化性质。
The influence of simple salts on the ion exchange and protonation equilibria of an amphoteric ion-exchange resin, which has strong base and weak acid moieties in a single functional group fixed onto the styrene-DVB matrix, has been investigated. Concentrations of ionic species in the amphoteric ion-exchange resin in equilibrium with various sodium salt solutions were estimated by ^23Na NMR spectroscopy. For the NaClO_4 system, the ratio of sodium ion concentration in the resin phase to that in the equilibrium solution was greater than 1 and increased with a decrease in the salt concentration. In contrast to an ordinary cation-exchange resin, the ion exchange behavior of Mg^2+ and Ca^2+ on the amphoteric ion-exchange resin showed a marked dependence on the kinds of salts: the distribution coefficients for the NaCl system were independent of the salt concentration, while the log D vs. log[Na^+] plots for the NaClO_4 system showed linear relationships with slopes being neither –2 nor 0. Apparent protonation constants of the carboxylate in the functional group of the resin in equilibrium with NaClO_4 solutions were greater than those with NaCl solutions. The ion exchange and protonation properties of the amphoteric ion-exchange resin were elucidated on the basis of the information about the salt concentrations in the resin phase estimated by the NMR method.
离子交换树脂/溶液界面离子的局部结构
DOI：
--
发表时间：
2005
期刊：
Journal of Chromatography A 1085
影响因子：
--
作者：
Makoto Harada;Tetsuo Okada
通讯作者：
Tetsuo Okada