Heavy Metal Recognition and Separation from Aqueous Media with Surface-Embedded Hosts

该项目的目标是开发一种分离系统，可以有效地从水中提取重金属，特别是锕系元素和镧系元素，以解决环境污染问题。由于重金属对生态系统的持续风险和对人类健康的潜在危害，从环境水源中去除重金属是一项紧迫的研究挑战。这样的重金属分离过程需要能够选择性结合锕系元素的分子。然而，设计这些分子是困难的，因为重元素的配位谱在很大程度上是相似的。此外，液-液萃取系统不如固相萃取系统理想。研究人员将采用一种更简单、更有效、易于重复使用的基于流的方法。研究方法包括开发一种利用柔性空腔和分子的创新金属提取系统。这些分子具有基于形状的分子识别和高亲和力的金属结合能力，能够捕获和去除环境水中的重金属。该项目还为研究生和本科生提供有机、环境和分析化学与材料工程领域的跨学科研究培训。该项目旨在开发嵌入表面的柔性小分子含腔分子，称为腔体。空腔和受体可以在没有有机溶剂的情况下直接从水相中选择性地识别和分离重金属离子。腔体和受体的灵活性和可调性将提供一个独特的平台，将允许结合金属的强选择性。选择性可以通过在空腔和分子中加入外部小分子客体来调节；这些来宾可以用来触发从空腔中释放金属。该研究方法结合了该团队在基于表面的分子识别和柱分离方面的专业知识，以：(1)将空腔结合到涂层毛细管中进行选择性金属离子结合和提取，(2)研究这种选择性识别背后的动力学和热力学因素，以及(3)进行锕系元素和重金属分离，并在与水流动的界面上触发释放。这些研究将扩展到更大规模的应用，即填充柱将被用于选择性金属分离和触发释放。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The goal of this project is to develop a separation system that can effectively extract heavy metals, specifically actinides and lanthanides, from water to address environmental contamination. Removing heavy metals from environmental water sources is a pressing research challenge due to their persistent risk to ecosystems and potential harm to human health. Such a heavy metal separation process requires molecules that can selectively bind actinides. However, designing these molecules is difficult, as the coordination profiles of heavy elements are largely similar. Additionally, liquid-liquid extraction systems are less desirable than solid-phase extractions. The investigators will apply a simpler and more efficient flow-based method that can be easily reused. The research approach involves developing an innovative metal extraction system utilizing flexible cavitand molecules. These molecules are capable of shape-based molecular recognition and high-affinity metal binding, enabling the capture and removal of heavy metals from environmental water. This project also provides graduate and undergraduate students with interdisciplinary research training in areas that bridge organic, environmental, and analytical chemistry with materials engineering.This project aims to develop flexible, small molecule cavity-containing molecules known as cavitands that are embedded at surfaces. The cavitand receptors enable the selective molecular recognition and separation of heavy metal ions directly from the aqueous phase without organic solvents. The flexibility and tunability of the cavitand receptors will provide a unique platform that will allow strong selectivity for binding metals. The selectivity can be tuned by adding external small molecule guests to the cavitand molecule; these guests can be used to trigger the release of the metals from the cavitand. The research approach combines the team’s expertise in surface-based molecular recognition and column separation to (1) incorporate the cavitands in coated capillaries for selective metal ion binding and extractions, (2) study the kinetic and thermodynamic factors behind this selective recognition, and (3) perform actinide and heavy metal separations and triggered release at interfaces with aqueous flow. These studies will be extended to larger-scale applications, whereby packed columns will be exploited for selective metal separation and triggered release.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.