Collaborative Research: Cyclodextrin-Based 2D Materials for the Treatment of Legacy and Emerging Perfluoroalkyl Substances

供水中的全氟烷基物质和多氟烷基物质(PFAS)对环境和人类健康构成威胁。标准的净水方法一般不能有效去除全氟辛烷磺酸。这项研究将探索一种潜在的变革性方法，设计环境相容的吸附剂用于去除全氟辛烷磺酸，研究活动将直接促进对选择性去除饮用水水源中全氟辛烷磺酸的材料的发现和基本了解。佛罗里达国际大学和北卡罗来纳州立大学之间的这项研究合作将通过汇集一个由本科生、研究生、博士后研究助理和来自不同州两个机构的研究人员组成的研究团队来促进教学、培训和学习。该项目将通过多学科研究经验、参加科学研讨会、专业发展和参与外联活动，为代表人数不足的学生提供一个宝贵的环境。项目成果将通过同行评议的出版物、在科学会议上的陈述以及特别陈述和研讨会广泛传播。此外，还计划举办一系列网络研讨会，以提高公众对全氟辛烷磺酸的健康风险的认识，并教育供水商有关去除全氟辛烷磺酸的有效方法，以保护人类健康和帮助确保国家的供水。这项研究的总体目标是探索环境友好型氨基-β-环糊精(Am-β-CD)与氧化石墨烯材料的组合，用于修复遗留和新兴的全氟辛烷磺酸。氧化石墨烯将与官能化的环糊精(CDS)相连，用于修复传统的全氟烷基醚酸和新兴的全氟烷基醚酸，如GenX和短链全氟烷基醚。初步研究结果表明，β-环糊精(β-CD)能很好地包裹各种PFAS，其结合常数高达10^5M^-1，在溶液中对PFAS的络合率高达95%。尽管该小组展示了结合使用β-CD和活性碳来强化全氟辛酸(PFOA)的去除，但对全氟辛酸的Cd络合以及如何利用Cd：PFAS的复合性质进行修复还缺乏基本的了解。这一知识差距阻碍了对全氟辛烷磺酸监测和水处理的这些系统的优化。这项研究将检验这样一种假设，即Am-β-Cd：PFAS络合物将在与环境相关的条件下持续存在，这样基于Am-β-Cd的石墨烯氧化物吸附剂可以用于修复PFAS。在强有力的初步证据和聚集的研究人员的广泛经验的指导下，该小组将追求两个具体目标：(1)测定am-beta-CD：PFAS络合物的结合常数和详细表征；(2)使用am-beta-CD附着的石墨烯-氧化物基质修复PFAS。取消短链和新兴的全氟辛烷磺酸将是最高优先事项。这项研究将有助于从根本上理解PFASs和Cd之间的分子相互作用，以及Cd基二维纳米吸附剂的应用。该项目预计将提供对制定可持续的PFAS补救战略至关重要的信息。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The presence of per- and polyfluoroalkyl substances (PFASs) in water supplies is a threat to environmental and human health. Standard water purification methods are generally ineffective for PFAS removal. This research will explore a potentially transformative approach to engineering environmentally compatible adsorbents for PFAS removal, and the research activities will directly advance discovery and fundamental understanding of materials that selectively remove PFASs from drinking water sources. This research collaboration between Florida International University and North Carolina State University will promote teaching, training, and learning by bringing together a research team composed of undergraduate students, graduate students, a postdoctoral research associate, and researchers from two institutions in different states. This project will provide a valuable environment for underrepresented students through multidisciplinary research experiences, participation in scientific workshops, professional development, and engagement in outreach activities. Project results will be broadly disseminated through peer-reviewed publications, presentations at scientific meetings, and special presentations and seminars. Additional a web seminar series is planned to enhance the public awareness of the health risks of PFASs and educate water suppliers on effective methodologies for PFAS removal to protect human health and help secure the Nation's water supply. The overall objective of the research is to explore the combination of environmentally friendly amino beta-cyclodextrins (am-beta-CDs) and graphene oxide-based materials for the remediation of legacy and emerging PFASs. Graphene oxide will be linked to functionalized cyclodextrins (CDs) for the remediation of legacy PFASs and emerging perfluoroalkylether acids, such as GenX, and short-chain PFASs. Preliminary results show that beta-cyclodextrin (beta-CD) readily encapsulates a variety of PFASs with association constants up to 10^5 M^-1, resulting in complexation of up to 95% of PFAS in solution. While the team has demonstrated enhanced removal of perfluoro octanoic acid (PFOA) using beta-CD in combination with activated carbon, there is a lack in the fundamental understanding about the CD complexation of PFASs and how the CD:PFAS complex properties may be exploited for remediation. This knowledge gap prevents the optimization of these systems for PFAS monitoring and water treatment. This research will test the hypothesis that am-beta-CD:PFAS complexes will persist in environmentally relevant conditions such that am-beta-CD-based graphene oxide adsorbents can be utilized for PFAS remediation. Guided by strong preliminary evidence and the extensive experience of the assembled researchers, the group will pursue two specific objectives: (1) Determination of binding constants for and detailed characterization of am-beta-CD:PFAS complexes; and (2) employ am-beta-CD-attached graphene-oxide matrices for remediation of PFASs. Removal of short-chain and emerging PFASs will be the highest priority. The study will contribute to the fundamental understanding of the molecular interactions of PFASs and CDs and the utility of CD-based two-dimensional nano-adsorbents. The project is expected to provide information critical for the development of sustainable strategies for PFAS remediation.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.