CAREER: Mechanistic understanding of the nanoscale interactions of structurally tunable 3D assemblies of MXenes-polyelectrolytes

职业：对 MXenes-聚电解质结构可调 3D 组件的纳米级相互作用的机理理解

• 批准号: 2238908
• 负责人: Nader Taheri Qazvini
• 金额: $ 62.32万
• 依托单位: University of South Carolina at Columbia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2028-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2238908&HistoricalAwards=false
• 关键词: CAREER; Mechanistic; understanding; nanoscale; interactions

Functional materials that predominantly absorb electromagnetic waves are desired for several applications relevant to the security and prosperity of the United States. These materials have a wide range of applications, including but not limited to preventing the interference of aircraft digital instruments, mitigating signal jamming, enhancing the performance of wireless devices, and safeguarding control of electronics for power grid systems. Most of the electromagnetic shields that are widely used at present rely mainly on reflecting the incident waves, which can result in secondary pollution. This Faculty Early Career Development project will combine experimental and computational studies to investigate how the molecular interactions between charge-containing polymers and two-dimensional carbides MXenes can be utilized to create functional materials with tunable electromagnetic wave absorption. This project will develop a science-based connection between the chemistry of charged macromolecules and MXenes and the mechanisms by which they interact, and form intricate, hierarchical nanoscale structures. In addition, this project will provide opportunities for high school, undergraduate, and graduate students, as well as STEM teachers, to engage in hands-on experiments and workshops. The project also involves curriculum development related to the synthesis, characterization, and application of hybrid functional materials based on nanoscale interactions. Regional research symposia on two-dimensional materials will also be organized to facilitate knowledge-sharing among the broader scientific community.The integration of MXenes and charged polymers within three-dimensional hybrid structures presents an enticing prospect for developing hybrid materials with adjustable mechanical and electrochemical properties. Nevertheless, creating such three-dimensional assemblies can prove difficult due to the complex surface chemistry of MXenes, which can result in uncontrolled interactions and, ultimately, aggregation. A key challenge in the field of MXene nanomaterials is gaining a fundamental understanding of these interactions and discovering methods to manipulate them effectively. This CAREER project addresses this challenge by integrating experimental and computational modeling through three interconnected research thrusts. The first thrust focuses on comprehending the nanoscale interactions between MXenes and polyelectrolytes, while the second thrust aims to exploit these interactions to direct the 3D bottom-up assembly. The third thrust involves the bottom-up structural modulation of electromagnetic wave absorption. The dynamics of assembly and the development of morphology and composition will be studied at multiple length scales. The regulation of morphology is accomplished by managing the conformation of the adsorbed polymer chains on MXene nanosheets, which controls the nanostructure of the MXene-polyelectrolyte heterointerface. The impact of various molecular characteristics of polyelectrolytes and MXenes, as well as hydrodynamic forces, on their interactions at heterointerfaces and the assembly of MXenes-polyelectrolyte into hybrid structures will be explored. This project will also demonstrate how controlling the interface nanostructure can lead to the creation of hybrid materials with improved microwave absorption, which arises from tunable electrical conductivity and interfacial polarization. The fundamental knowledge obtained from this research has the potential to inform the development of other MXene-based hybrids for applications in antimicrobial materials and water treatment. This project will integrate research, teaching, and outreach initiatives to advance scientific innovation while educating and inspiring a diverse, inclusive group of future STEM students and researchers.This project is jointly funded by the CBET Nanoscale Interactions Program and the Established Program to Stimulate Competitive Research (EPSCoR).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.

主要吸收电磁波的功能材料是与美国的安全和繁荣有关的几种应用所需要的。这些材料具有广泛的应用，包括但不限于防止飞机数字仪表的干扰，减轻信号干扰，增强无线设备的性能，以及保障电网系统的电子控制。目前广泛使用的电磁屏蔽主要依靠反射入射波，会造成二次污染。这个教师早期职业发展项目将结合实验和计算研究来研究如何利用含电荷聚合物和二维碳化物MXenes之间的分子相互作用来创造具有可调谐电磁波吸收的功能材料。该项目将在带电大分子和MXenes的化学性质及其相互作用机制之间建立科学联系，并形成复杂的、分层的纳米级结构。此外，该项目将为高中生、本科生和研究生以及STEM教师提供参与动手实验和研讨会的机会。该项目还包括与基于纳米级相互作用的杂化功能材料的合成、表征和应用相关的课程开发。还将组织关于二维材料的区域研究专题讨论会，以促进更广泛的科学界之间的知识共享。MXenes和带电聚合物在三维杂化结构中的集成为开发具有可调节机械和电化学性能的杂化材料提供了诱人的前景。然而，由于MXenes复杂的表面化学性质，可能导致不受控制的相互作用，最终导致聚集，因此创建这样的三维组件可能是困难的。MXene纳米材料领域的一个关键挑战是获得对这些相互作用的基本理解，并发现有效操纵它们的方法。CAREER项目通过三个相互关联的研究重点，将实验和计算建模相结合，解决了这一挑战。第一个推力侧重于理解MXenes和聚电解质之间的纳米级相互作用，而第二个推力旨在利用这些相互作用来指导三维自下而上的组装。第三个推力涉及电磁波吸收的自下而上的结构调制。组装的动力学以及形态和组成的发展将在多个长度尺度上进行研究。通过控制MXene纳米片上吸附的聚合物链的构象来调控形貌，从而控制MXene-聚电解质异质界面的纳米结构。将探讨聚电解质和MXenes的各种分子特性以及水动力对它们在异质界面上的相互作用以及MXenes-聚电解质组装成杂化结构的影响。该项目还将展示如何控制界面纳米结构，从而创造出具有改进微波吸收的混合材料，这源于可调谐的导电性和界面极化。从这项研究中获得的基本知识有可能为开发其他基于mxeni的杂化材料提供信息，用于抗菌材料和水处理。该项目将整合研究、教学和外展活动，以推进科学创新，同时教育和激励多元化、包容性的未来STEM学生和研究人员。该项目由CBET纳米尺度相互作用项目和促进竞争性研究的既定项目（EPSCoR）共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。