权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Development of ion-exchange resins with pendant groups promoting dehydration of hydrophilic anions

开发具有促进亲水阴离子脱水的侧基的离子交换树脂

基本信息

批准号：
16550135
负责人：
YUCHI Akio
金额：
$ 1.92万
依托单位：
Nagoya Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16550135/
关键词：
ion-exchange resin dehydration coadsorption anion cation hydration number hydrogen bond bridging coordination

项目摘要

The hydration numbers of anions were determined on two strongly basic anion exchange resins (tetramethylammonium- and hydroxyethyltrimethylammonium-types, hereafter referred to as SBA1 and SBA2) and one weakly basic anion exchange resin (trimethylamino-type, hereafter referred to as WBA), which were dried in the air at a relative humidity of 35% at 298 K. The anions on SBA1 had increasing hydration numbers with a decrease in Gibbs hydration energy (ΔG_<hyd>) in water, with a limiting hydration number of 3 observed in the range of ΔG_<hyd><-400 kJ mol^<-1>. The selectivity coefficient of the anions accordingly decreased with the decrease in ΔG_<hyd>, to a limiting value of 10^<-1> in the range of ΔG_<hyd><-400 kJ mol^<-1>. The anions on WBA were more dehydrated than those on SBA1. The remarkably smaller hydration numbers of H_2P0_<4^->,F^-, and HCOO^- on WBA are ascribed to the hydrogen bonding between the H atom on the protonated amine group and the negatively charged basic sites on the anions. There were, however, no significant differences between the selectivity coefficients of such anions on WBA and those on SBA1. In contrast, only H_2P0_<4^-> was extremely dehydrated on SBA2 and SBA3 with an increase in selectivity coefficient. The PM3 calculation suggested the hydrogen bonding between the H atom on the hydroxyethyl group and the O atom of H_2PO_<4^->. The hydrogen bonding which occurs at a different site from the electrostatic attraction sites is effective to enhance the dehydration and adsorption of hydrophilic polyatomic anions. The hydration states of the anions on SBA1 may well simulate those of the anions distributed in benzene together with counter cations.

测定了两种强碱性阴离子交换树脂（四甲基铵型和羟乙基三甲铵型，以下简称SBA1和SBA2）和一种弱碱性阴离子交换树脂（三甲胺型，以下简称WBA）在298 K下相对湿度为35%的空气中干燥后阴离子的水化数。SBA1上阴离子的水化数随着水中吉布斯水化能（ΔG_<hyd>）的降低而增加，在ΔG_<hyd><-400 kJ mol^<-1>范围内的极限水化数为3。阴离子的选择性系数随ΔG_<hyd>的减小而减小，在ΔG_<hyd><-400 kJ mol^<-1>范围内达到10^<-1>的极限值。WBA上的阴离子比SBA1上的阴离子脱水更严重。WBA上的H_2P0_<4^->、F^-和HCOO^-水化数明显较小，这是由于质子化胺基上的H原子与阴离子上带负电的碱性位之间的氢键作用所致。然而，这些阴离子在WBA和SBA1上的选择性系数没有显著差异。相比之下，只有H_2P0_<4^->在SBA2和SBA3上极度脱水，选择性系数增加。PM3计算表明H_2PO_<4^->的羟基上的H原子与O原子之间存在氢键。发生在不同于静电吸引位点的氢键可以有效地增强亲水性多原子阴离子的脱水和吸附。SBA1上阴离子的水合状态很好地模拟了苯中阴离子与反阳离子的水合状态。