LEAPS-MPS: Photodynamic Hybrid Polymer Network Sponges and their Structure-Property Relationships

该奖项的全部或部分资金来自《2021年美国救援计划法案》(公法117-2)。非技术概述：这项研究的目标是对一系列选择性的、光激活的智能材料海绵有一个基本的了解，这些海绵有助于环境修复无处不在的有毒污染物，如全氟烷基(PFAS)和永久化学品。该项目还将整合一支不同的研究团队来开展这项工作，并影响、培训和指导广泛的初中生、高中生和本科生，以招募和培训他们，为未来在美国科学工作中的成功做准备。具体地说，PI的团队将合成硅基光敏海绵，这种海绵可以捕获特定物质并经历独特的可逆收缩现象，然后根据需要以特定的光波长和能量驱逐它们。这种光驱动的过程在硅网络等固体材料中非常复杂，这项研究将有助于了解这些响应海绵在具有不同的构建块时的行为，这些构建块要么改变形状，要么用光分解。调查还将确定材料的结构如何影响它们的行为，以及根据需要选择性地吸收和释放显性物质的能力。最后，将详细介绍它们在修复难以从水源中选择性分离的全氟辛烷磺酸类化合物方面的能力和效率。不同种族和民族的高中生和本科生将有机会为这一项目的发展做出贡献，并与北卡罗来纳州立大学的科学家一起接受实验室培训，以帮助学生群体向以科学为基础的职业转变。将在少数族裔(密西西比州沃伦/俄亥俄州托莱多)高度集中的地区举办一系列研讨会，重点是智能光响应材料、环境补救和健康优先事项，以及在实验室中花时间跟踪实习科学家的机会。这些机会将有助于吸引和留住大批科学家。技术概述：PI和他的团队将开发可重复使用、坚固耐用的高孔率“智能”海绵，这种海绵在光照射后可以经历巨大的体积变化，最终用于持久性污染物的环境修复(如全氟辛烷磺酸)。Q-倍半硅氧烷网络的凝胶和固体将与设计的以烯丙基或乙烯基官能化为特征的可光切换和动态基团进行交联。这些新型光响应材料的结构-性能关系将被确定以改善光响应行为，决定什么构成高性能材料及其物质吸收/释放能力(即石化产品)。与传统聚合物相比，倍半硅氧烷作为动态材料的研究仍然较少，原因是官能化的复杂性和倍半硅氧烷固有的刚性，尽管有机硅材料在各种家用和工业产品中很普遍。这些材料克服了合成、结构和驱动方面的限制，比典型的光动力海绵(如水凝胶、有机凝胶)具有优势。这些包括由于硅氧烷核心提高了环境稳定性和更好的机械性能，出色地控制了与许多目标物质一起工作的可调性，以及容易的结构组装。这项研究还将扩大探索改进的方法，以捕获致癌的永久化学品，如全氟烷基物质(PFAS)，以改善人类和环境健康。对于教育活动，大学生将参与与地区公司的科学努力，以建立职业发展关系，并体验现实世界的科学挑战，作为公共影响外联的一部分。将为不同的初中生和高中生提供指导，帮助他们参加聚合物研讨会和实验室研究经验，以深入了解科学的重要性，以及拟议的研究可能如何在个人和更广泛的范围内影响社会。这些倡议旨在通过动手互动、建立联系并与来自不同背景的不同科学家群体合作，增加青年在STEM领域的参与。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。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).NON-TECHNICAL SUMMARY:The goal of this research is to develop a fundamental understanding of a series of selective, light activated smart material sponges useful for environmental remediation of omnipresent toxic pollutants such as perfluoroalkyl (PFAS) “forever chemicals.” This project will also meld together a diverse team of researchers to carry out this work and to influence, train, and mentor a broad representation of middle, high school and undergraduate students to recruit and train them for future success in the U.S. science workforce.Specifically the PI's group will synthesize silicon-based light-responsive sponges that can capture specific substances and undergo unique reversible shrinking phenomena to then expel them on demand with certain light wavelengths and energies. This light-driven process is quite complex in solid materials such as silicon networks and this research will aid in gaining an understanding of how these responsive sponges behave when having different building blocks that either change shape or break apart using light. The investigation will also determine how the structures of the material influence their behavior and ability to selectively soak up and release explicit substances on demand. Lastly, their abilities and efficiencies in remediation of PFAS type compounds, which are difficult to selectively isolate from water sources, will be detailed. Racially and ethnically diverse high school and undergraduate students will have the opportunity to contribute to the development of this project and gain laboratory training with scientists at BGSU to aid in the diversification of the student body toward science-based careers. A series of workshops focused on smart light responsive materials, environmental remediation and health priorities as well as the opportunity to spend time shadowing student scientists in the laboratory will be conducted in local areas with high concentrations of under-represented minorities (Warren, MI / Toledo, OH). These opportunities will assist in both attracting and retaining an expansive array of scientists. TECHNICAL SUMMARY:The PI and his group will develop reusable and robust high porosity "smart" sponges that can experience large volume changes after light irradiation to ultimately be used for environmental remediation of persistent pollutants (e.g. PFAS). Gels and solids of Q-silsesquioxane networks will be cross-linked with designed photoswitchable and dynamic groups that feature allyl or vinyl functionalization. Structure-property relationships of these novel photoresponsive materials will be determined to improve photoresponsive behaviors, determine what makes a high-performance material and its substance uptake/release ability (i.e. petrochemicals). Silsesquioxanes’ use as dynamic materials remains less explored than traditional polymers due to the intricacies of functionalization and silsesquioxanes’ inherent rigidity, despite the prevalence of silicone materials in a variety of household and industrial products. These materials offer advantages over typical photodynamic sponges (i.e. hydrogels, organogels), by overcoming synthetic, structural, and actuation limitations. These include increased environmental stabilities and better mechanical properties due to siloxane cores, excellent control of tunability to work with many target substances, and facile structural assembly. This research will also expand the exploration of improved methods for the capture of cancer-causing persistent “forever chemicals” such as perfluoroalkyl substances (PFAS) for the improvement of human and environmental health. For educational initiatives, university students will participate in scientific endeavors with regional companies to build career development relationships and experience real-world scientific challenges as part of public impact outreach. Mentorship will be given to a diverse set of middle and high school students as they participate in polymer workshops and laboratory research experiences to provide insight on the importance of science and how the proposed research may impact society on an individual and broader scale. These initiatives aim to increase youth involvement in the STEM fields by hands-on interactions, connections, and working with a diverse group of scientists from various backgrounds..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.