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

纳米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、光学设备以及医疗过程和设备。纳米氧化铟(NIO)是一种掺杂的金属氧化物颗粒，广泛应用于触摸屏、电子墨水和有机发光二极管等电子显示模块中。这些产品的制造过程和报废事件可能会成为硝化氮对人类和自然环境的暴露途径，从而引起对生态和纳米毒性的关注。该项目系统地评估了晶体性质(在原子尺度上)对硝基的环境健康和安全的影响。本项目的目的是确定硝酸根的主要物理化学性质和禁带能量学随锡掺杂浓度和分布的变化，并阐明这些纳米双金属的去向、传输、转化和毒性的机理。本研究将针对下列目标：(1)通过控制掺杂浓度和分布合成具有可调带结构的硝酸根；(2)制备和表征各种锡掺杂的硝酸根样品，以获得详细的晶体结构、双金属形貌和胶体性质；(3)检测聚集动力学、分维以及多孔介质的传输随离子强度和有机质组成的变化；(4)利用带隙能量学和ROS测量方法评估微生物毒性(对浮游生物膜细胞)和毒性机制；(5)评估硝酸根的化学转化以及转化材料的命运和毒性。这项研究将是此类研究的第一次，利用原子水平上锡掺杂分布和浓度的受控变化引起的硝酸根的基本电子和物理化学性质的变化来阐明水环境中的命运、传输和毒性的机制。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和具有商业重要性的下一代纳米材料Nito的环境影响。Nito被用作触摸屏设备中的透明催化剂，具有较高的回收效率和相对较短的寿命，因此有必要了解它们的环境安全性。该项目取得的成果将使人们更好地了解环境、健康和安全，从而产生直接的社会效益。在外展和教育方面，督学将继续从代表性不足的组别招收学生的良好纪录。得克萨斯大学奥斯汀分校S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被引入这一尖端纳米材料和微生物学研究，利用该大学的毕业生与工程本科生(GLUE)和德克萨斯研究经验(TREX)项目相联系。圣胡安-迭戈高中(有85%的拉美裔学生)的多管齐下的外展活动将通过研讨会和动手实验对高中生产生深远的教育影响。

#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.