在纳米过过程中,离子水结构和选择性运输行为对水溶液化学的反应
Chenghai Lu1,2, Zhibin Chen1,2, You Wu1,2
1State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Environmental science & technology
|June 13, 2024
概括
溶液化学影响离子水结构和纳米过 (NF) 选择性. 了解离子-水相互作用是控制离子运输和提高NF膜性能的关键.
科学领域:
- 环境科学 环境科学
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
背景情况:
- 通过纳米过 (NF) 膜的离子选择性传输对于水净化和分离过程至关重要.
- 水溶液化学对离子水结构的影响及其对NF选择性的影响仍然是一个重要的研究缺口.
- 了解离子水化如何影响运输对于优化NF膜性能至关重要.
研究的目的:
- 在不同的水溶液条件下研究化物 (Cl-) 和酸盐 (NO3-) 离子的水合分布.
- 在纳米过过程中将离子水结构与跨膜选择性相关联.
- 通过操纵水化相互作用来阐明调节离子跨膜运输的机制.
主要方法:
- 使用 *in situ* 液体飞行时间二次离子质谱法 (TOF-SIMS) 来分析水化结构.
- 采用分子动力学 (MD) 模拟来补充实验发现和模拟离子行为.
- 研究了盐度,共存离子和pH对阳离子水合和NF选择性的影响.
主要成果:
- 证明了离子水结构,膜毛孔内的硬质效应和NF选择性之间的直接联系.
- 表明离子运输是由水-水结合和离子-水相互作用之间的平衡来调节的.
- 观察到强水化Cl-在盐度增加时表现出更高的排斥,而弱水化NO3-则表现出相反的趋势. 由于OH-竞争,较高的pH值降低了两个离子的水合数.
结论:
- 该研究更深入地了解了控制NF分离的机制,强调了离子水结构的关键作用.
- 研究结果强调,操纵离子-水和水-水相互作用可以有效地控制离子运输和膜选择性.
- 这项研究为设计具有定制离子选择性的先进NF膜所需的基本知识做出了贡献.
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