EAGER: Development of a Mechanistic Framework Correlating Quantum Dot Surface Chemistry and Subsurface Environmental Fate and Transport

EAGER：开发将量子点表面化学与地下环境归宿和传输相关的机制框架

• 批准号: 1505718
• 负责人: Jillian Goldfarb
• 金额: $ 10万
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1505718&HistoricalAwards=false
• 关键词: EAGER; Development; Mechanistic; Framework; Correlating

1505718Goldfarb, JillianThe interfacial interactions between quantum dots (QD) surface coatings and ecological surfaces are critical determinants of the environmental fate and transport of these materials. However, currently there is no foundational understanding of the mechanisms by which such interactions occur. Therefore it is necessary to examine and test every nanomaterial using a battery of tests to predict resulting subsurface behavior. This proposal will lay a foundation for a mechanistic understanding of the interplay between QD surface coatings and their subsurface reactions. Multivariate statistical analysis tools will be used to analyze data in a framework that reduces the experimental burden by correlating the composition of QD coatings with the environmental factors that influence nanoparticle behavior. By laying a mechanistic foundation for understanding of how QDs with varying structures respond to different environmental stimuli, the project may transform our approach to evaluating the environmental impacts of emerging nanomaterials from the test-and-observe approach to one of predict-and-verify. The long-term goal is to enable assessment of environmental impacts of manufactured nanomaterials in a combined computational and experimental framework. This is a radically different approach from the existing strategy of thoroughly test every new nanomaterial and involves an innovative methodology for developing a novel predictive tool.Core/shell semiconductor quantum dots (QDs) are heterogeneous nanomaterials with seemingly infinite applications and unknown potential effects on human health and the environment. As QDs transition from specialized research laboratories to components in consumer and biological devices, there is a need to develop an understanding of how they will interact, persist, and degrade in the environment. The objective of this proposal is to develop an experimental framework to enable a mechanistic understanding of the relationships between QD surface characteristics and the physico-chemical properties of the subsurface environment on the agglomeration, adsorption, and partitioning of core/shell QDs. This objective will be met by synthesizing QDs with four organic coating combinations (hydrophobic interactions or dative bonding, paired with electrostatic repulsions or steric hindrance). The nanoparticles will be fully characterized to assess their size, morphology, monodispersity, concentration, quantum yield and photoluminescence, crystalline structure, ratio of core and shell atoms, and ratio of coating to particle. To develop this mechanistic understanding, the agglomeration kinetics of QDs with common soil colloids, their partitioning behavior between octanol and water, and their adsorption to saturated porous media, all as a function of ionic strength and pH, will be measured. An initial framework using multivariate statistical analysis will enable the modeling and quantification of relationships between pH and ionic strength and the partitioning, agglomeration, and adsorption for each of the four coating possibilities.

量子点(QD)表面涂层和生态表面之间的界面相互作用是这些材料的环境命运和运输的关键决定因素。然而，目前对这种相互作用发生的机制还没有基本的了解。因此，有必要使用一系列测试来检测和测试每一种纳米材料，以预测由此产生的地下行为。这一建议将为从机理上理解量子点表面涂层与其亚表面反应之间的相互作用奠定基础。多元统计分析工具将被用来在一个框架内分析数据，该框架通过将量子点涂层的组成与影响纳米颗粒行为的环境因素相关联来减少实验负担。通过为理解具有不同结构的量子点如何响应不同的环境刺激奠定了机制基础，该项目可能会将我们评估新兴纳米材料对环境影响的方法从测试和观察方法转变为预测和验证方法。长期目标是能够在计算和实验相结合的框架内评估人造纳米材料对环境的影响。这是一种与现有的彻底测试每一种新的纳米材料的策略截然不同的方法，涉及到开发一种新型预测工具的创新方法。核/壳半导体量子点(QD)是一种似乎具有无限应用和对人类健康和环境的未知潜在影响的异质纳米材料。随着量子点从专门的研究实验室过渡到消费和生物设备中的组件，有必要了解它们将如何在环境中相互作用、持久存在和降解。这项提议的目的是建立一个实验框架，以便能够从机理上理解量子点表面特征和地下环境的物理化学性质对核/壳量子点的聚集、吸附和分配的关系。这一目标将通过四种有机涂层组合(疏水相互作用或配位键，与静电斥力或空间位阻配对)来合成量子点。将对纳米颗粒进行全面表征，以评估其尺寸、形貌、单分散性、浓度、量子产率和光致发光、晶体结构、核/壳原子比以及涂层/颗粒比。为了加深对这一机理的理解，我们将测量量子点与常见土壤胶体的团聚动力学，它们在辛醇和水中的分配行为，以及它们在饱和多孔介质中的吸附，所有这些都是离子强度和pH的函数。使用多元统计分析的初始框架将能够建模和量化pH和离子强度之间的关系，以及四种涂层可能性的分配、团聚和吸附。