Design of Safer Carbon-Based Nanomaterials: The Impact of Surface Modifications on Toxicity and Environmental Fate and Transport

提案标题： 更安全的碳基纳米材料的设计：表面改性对毒性和环境归宿及运输的影响 朱莉齐默尔曼机构：耶鲁大学提案编号：CBET-0854373该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。本研究的目的是发展设计碳纳米管所需的基本理解，降低对人类健康和环境的风险。 支持这一目标的知识将通过对具有良好特征的原始和功能化碳纳米管（单壁碳纳米管和多壁碳纳米管）的生物毒性测试来收集。 然后将评估改性的CNT在代表性环境条件下的稳定性，并且将重新评估在环境条件下经历转化的那些CNT的毒性特性。 完成拟议的工作将涉及以下任务：（i）CNT的合成，（ii）CNT的表面官能化，（iii）CNT的表征，（iv）CNT生物毒性的评价，（v）CNT在水生系统中的环境转化的表征，（vi）CNT的聚集，（vii）分析由环境条件引起的变化对毒性的影响，及（viii）考虑政策影响。 他们将合成定义明确的SWCNTs和MWCNTs。 除了测试原始CNT外，他们还将测试一系列功能化，这些功能化导致CNT具有增强的溶解性和一系列极性。 这些包括氨基、羟基、羧基、磺酸根、烷基和吡咯烷基官能化的CNT，以及氟化的SWCNT，迄今为止已知的最密集官能化的CNT。 仔细表征的合成和功能化的碳纳米管是至关重要的，从生物毒性研究形成有意义的结论。 他们将使用先进的表征工具来获得有关CNT纯度和物理化学性质的信息，包括拉曼、FTIR和近红外荧光光谱; TEM、TGA和zeta电位测量。 然后，他们将测试原始和功能化CNT的生物毒性，以深入了解CNT化学和物理性质对其毒性的作用。 一旦释放到水环境中，功能化的CNT将经历化学和物理转化。 他们将研究化学功能化在环境条件下的稳定性以及这些转化对CNT生物毒性的影响。 最后，将讨论的结果的影响，有关政策的设计更安全的碳纳米管。 本研究的结果将提供有关以下方面的信息：（i）导致毒性降低或无毒性的CNT表面改性，以及（ii）这些改性在环境条件下的稳定性，以长期保护人类健康和环境。 最终，这些信息将用于设计下一代CNT。目前的研究表明，在科学和工程课程和专业中，如果将该项目所关注的问题纳入课程，则有可能增加妇女和代表性不足群体的招聘和保留。 预计耶鲁大学也将出现类似的趋势，该大学的工程专业女本科生毕业率在全国最高。 虽然这个项目将作为本科生和研究生的研究机会的来源，以及被整合到耶鲁大学现有的课程，他们也有一个独特的和创新的贡献，以扩大这个项目的影响。 与耶鲁大学的教职员工和相关学生一起？在皮博迪自然历史博物馆，项目小组将致力于为7-12年级的学校课程开发一个适合年龄的模块，其中包括绿色产品设计和环保制造。 通过这种经验，这些学生将获得与设计和开发符合环境，经济和社会目标的产品和工艺以及消费者在系统中的作用相关的挑战有更好的理解。

Proposal Title: Design of Safer Carbon-Based Nanomaterials: The Impact of Surface Modifications on Toxicity and Environmental Fate and TransportPrincipal Investigator: Julie Zimmerman Institution: Yale UniversityProposal No: CBET- 0854373This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The objective of this study is to develop the fundamental understanding necessary to design carbon nanotubes with reduced risk to human health and the environment. Knowledge to support this goal will be gathered through biotoxicity testing of well-characterized pristine and functionalized carbon nanotubes, both single-walled carbon nanotubes, SWCNTs, and multi-walled carbon nanotubes, MWCNTs. The modified CNTs will then be evaluated for stability under representative environmental conditions, and those CNTs that undergo a transformation in environmental conditions will be reevaluated for toxic characteristics. Completion of the proposed work will involve the following tasks: (i) synthesis of CNTs, (ii) surface functionalization of CNTs, (iii) characterization of CNTs, (iv) evaluation of CNT biotoxicity, (v) characterization of environmental transformations of CNTs in aquatic systems, (vi) aggregation of CNTs, (vii) analysis of the impacts of changes resulting from environmental conditions on toxicity, and (viii) consideration of policy implications. They will synthesize well-defined SWCNTs and MWCNTs. In addition to the testing of pristine CNTs, they will test a range of functionalizations that result in CNTs with enhanced solubility and a range of polarities. These include amino, hydroxyl, carboxy, sulfonate, alkyl, and pyrrolidinyl functionalized CNTs, as well as fluorinated SWCNTs, the most densely functionalized CNTs known to date. Careful characterization of the synthesized and functionalized CNTs is critical for the formation of meaningful conclusions from the biotoxicity studies. They will use advanced characterization tools to obtain information about the CNT purity and physical and chemical properties, including Raman, FTIR, and Near IR fluorescence spectroscopy; TEM, TGA, and zeta potential measurement. They will then test the biotoxicity of the pristine and functionalized CNTs to gain insights into the role of CNT chemical and physical properties on their toxicity. Once released into the aquatic environment, functionalized CNTs will undergo chemical and physical transformations. They will investigate the stability of the chemical functionalizations under environmental conditions and the impact of these transformations on CNT biotoxicity. Finally, the implications of the results for policies regarding the design of safer CNTs will be discussed. The results from this study will provide information on (i) surface modifications to CNTs that result in reduced or no toxicity, and (ii) the stability of these modifications in environmental conditions for long-term protection of human health and the environment. Ultimately, the information will be used to design the next generation of CNTs. Current research demonstrates the potential for an increase in the recruitment and retention of women and underrepresented groups in science and engineering courses and majors when the type of issues this project is focused on are introduced into the curriculum. It is anticipated that similar trends will be observed at Yale University, which already graduates the highest percentage of female undergraduate engineering students in the country. While this project will serve as a source of research opportunities for undergraduate and graduate students as well as be integrated into existing courses at Yale, they also have a unique and innovative contribution to broaden the impacts of this project. Together with staff and associated students at Yale?s Peabody Museum of Natural History, the project team will be working to develop an age appropriate module for their School Programs for grades 7-12 on sustainability to include components on green product design and environmentally benign manufacturing. Through this experience, these students would gain a better understanding of the challenges associated with designing and developing products and processes that meet environmental, economic, and social goals as well as the role of consumers in the system.