UNS: Role of dopant concentration and distribution in the environmental behavior of indium tin oxide nanoparticles

UNS：掺杂剂浓度和分布在氧化铟锡纳米粒子环境行为中的作用

• 批准号: 1511826
• 负责人: Navid Saleh
• 金额: $ 29.99万
• 依托单位: University of Texas at Austin
• 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: 2015-06-15 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1511826&HistoricalAwards=false
• 关键词: UNS; Role; dopant; concentration; distribution

#1511826Saleh, Navid Nano-scale metal oxides are one of the most prepared and used engineered nanomaterials with applications in electronics, optical devices, and medical processes and devices. Nano-scale indium tin oxide (nITO) is one such doped metal oxide particle that is used heavily in electronic display modules such as touch screens, electronic inks, and organic light-emitting diodes. Manufacturing processes and end-of-life disposal events for these products might serve as exposure pathways of nITO to humans and the natural environment and thus raise concerns for eco- and nano-toxicity. This project systematically assesses the influence of crystal properties (at the atomic scale) on the environmental health and safety of nITO. The purpose of this project is to determine key physicochemical properties and band gap energetics of nITO as a function of the concentration and distribution of tin doping and to elucidate mechanisms for fate, transport, transformation, and toxicity of these nano-scale bimetallics. This study will address the following aims: (1) synthesize nITO with tunable band structure via control over dopant concentration and distribution; (2) sample preparation and characterization of nITO for a range of tin doping to gain detailed understanding of crystal structure, bimetallic morphology, and colloidal properties; (3) examination of aggregation kinetics, fractal dimension, and porous media transport as a function of ionic strength and organic matter composition; (4) evaluation of microbial toxicity (to planktonic and biofilm cells) and toxicity mechanisms using band gap energetics and ROS measurements; (5) assessment of chemical transformation of nITO and evaluation of fate and toxicity of the transformed materials. This study will be the first of its kind, using changes in fundamental electronic and physicochemical properties of nITO caused by controlled variations in tin doping distribution and concentration at the atomistic level to elucidate mechanisms of fate, transport, and toxicity in aquatic environments. The proposed work will generate critical and fundamental knowledge to better understand the environmental implications of a highly concerning and commercially important next- generation nanomaterial, nITO. nITO, that are utilized as transparent catalysts in touch-screen devices with higher recycling rate and relatively short lifetime, necessitate understanding their environmental safety. The results obtained from this project will result in direct societal benefit by providing better understanding of nTO environmental health and safety. In outreach and education aspects, the PIs will continue their strong track records of recruiting students from underrepresented groups. At least one graduate student from an underrepresented group will be attracted via the University of Texas at Austin?s Diversity Mentoring Fellowship, while undergraduate women and minority students will be brought into this cutting-edge nanomaterial and microbiology research utilizing the University's Graduates Linked with Undergraduates in Engineering (GLUE) and the Texas Research Experience (TREX) programs. Multi-pronged outreach activities at San Juan Diego High School (which has 85% Hispanic students) will have profound educational impact on the high school students through seminars and hands-on experiments.

#1511826Saleh，Navid 纳米级金属氧化物是制备和使用最多的工程纳米材料之一，应用于电子、光学设备以及医疗工艺和设备。纳米级氧化铟锡 (nITO) 就是一种这样的掺杂金属氧化物颗粒，广泛用于触摸屏、电子墨水和有机发光二极管等电子显示模块。 这些产品的制造过程和报废处理事件可能是 nITO 接触人类和自然环境的途径，从而引发对生态和纳米毒性的担忧。该项目系统评估了晶体特性（原子尺度）对 nITO 环境健康和安全的影响。该项目的目的是确定 nITO 的关键物理化学性质和带隙能量与锡掺杂浓度和分布的关系，并阐明这些纳米级双金属的命运、传输、转化和毒性机制。本研究将实现以下目标：（1）通过控制掺杂浓度和分布来合成具有可调谐能带结构的nITO； (2) 一系列锡掺杂的 nITO 的样品制备和表征，以详细了解晶体结构、双金属形态和胶体特性； (3) 检查聚集动力学、分形维数和多孔介质传输作为离子强度和有机物组成的函数； (4) 使用带隙能量学和 ROS 测量评估微生物毒性（对浮游和生物膜细胞）和毒性机制； (5)nITO化学转化的评估以及转化材料的归宿和毒性评价。 这项研究将是同类研究中的第一项，利用原子水平上锡掺杂分布和浓度的受控变化引起的 nITO 基本电子和物理化学性质的变化来阐明水生环境中的归宿、运输和毒性机制。拟议的工作将产生关键和基础知识，以更好地理解高度关注且具有商业重要性的下一代纳米材料 nITO 对环境的影响。 nITO 在触摸屏设备中用作透明催化剂，具有较高的回收率和相对较短的使用寿命，因此有必要了解其环境安全性。 该项目获得的结果将通过提供对 nTO 环境健康和安全的更好理解而产生直接的社会效益。 在外展和教育方面，PI 将继续其从代表性不足的群体中招收学生的良好记录。 德克萨斯大学奥斯汀分校的多样性指导奖学金将吸引至少一名来自代表性不足群体的研究生，而本科生女性和少数族裔学生将利用该大学的毕业生与本科生相关的方式参与这项尖端的纳米材料和微生物学研究工程（GLUE）和德克萨斯研究经验（TREX）项目。 圣胡安迭戈高中（该校有 85% 的西班牙裔学生）的多管齐下的外展活动将通过研讨会和实践实验对高中生产生深远的教育影响。