Collaborative Research: Studies of light-responsive novel metal and lanthanide-based nanocomposites: X-ray radiation enhancing and radioluminescence properties

纳米尺度的材料已经证明了一系列广泛而显著的特性，使它们适合于许多应用。纳米材料在温度、机械力、pH等外界刺激下的行为已经得到了广泛的研究。然而，纳米材料与电离辐射（如x射线）的相互作用在很大程度上仍未被探索。在纳米尺度上研究潜在的现象和理解电离辐射与物质的相互作用机制是材料化学中的一个未知问题，将产生有价值的信息，允许在核科学和技术中使用这种结构，用于医学、功率传感器、能量存储、辐射传感器和执行器。这项合作研究计划将研究一种对低能和高能x射线均有响应的新型多组分纳米材料。这项研究将对弗吉尼亚联邦大学（VCU）的机械与核工程专业产生巨大的教育影响。材料与辐射化学、先进纳米材料合成与制造的新知识将在本科和研究生课程中传播。这里提出的研究也将是詹姆斯麦迪逊大学（JMU）核科学的重大恩惠，并将包括本科生参与跨学科研究项目。在这个跨学科项目中，学生们将获得丰富的经验，为那些在核工程、应用光子科学、纳米科学、加速器物理或医学物理领域寻求职业发展的人，以及那些直接进入核工业或政府工作的人，创造大量的机会。本研究项目将促进对辐射剂量增强的基本机制和纳米复合材料与高能光子相互作用时的辐射发光响应的基本认识。本工作将建立在辐射与物质相互作用理论的基础上，并扩展到水介质中导致辐射增强现象的表面和界面效应。本项目重点研究三个方面：1)拓展多组分纳米材料的受控合成，探索其与电离辐射相互作用的机制；2)研究其放射发光和增强辐射性能；3)实施基于蒙特卡罗模拟的计算模型，根据纳米材料的化学成分和形态来评估物理增强对其放射敏化性能的贡献。实验工作将涉及化学、电化学和光谱技术，以量化辐射增强和材料光学特性中涉及的反应物质。计算工作将使用GEANT4粒子传输代码来模拟x射线与所研究的纳米结构的相互作用。最终，本研究将在固态中建立材料结构和性能之间的相关性，特别是考虑x射线参数（如x射线束的能谱和能量传递到系统的速率）对材料系统行为的影响。总的来说，所提出的实验和计算工具将导致对纳米材料的结构-性质关系的理解，并将推进辐射增强和辐射发光纳米材料的合成，评估和模拟，使其能够在各个领域实现。总体而言，参与这项工作的本科生和研究生都将有机会在JMU麦迪逊加速器实验室的加速器环境中获得实践经验，同时参与VCU和JMU的前沿跨学科研究。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。

Non-Technical SummaryMaterials at the nanoscale have evidenced a wide and remarkable set of properties that make them suitable for many applications. The behavior of nanomaterials under various external stimuli, such as temperature, mechanical forces, pH, etc., has been widely investigated. However, the interaction of nanomaterials with ionizing radiation, such as X-rays, remains largely unexplored. Investigating potential phenomena and understanding the interaction mechanisms of ionizing radiation with matter at the nanoscale is an unknown question in materials chemistry and will generate valuable information to allow the use of such structures in nuclear science and technology for applications in medicine, power transducers, energy storage, radiation sensors, and actuators. This collaborative research proposal will investigate a novel class of multicomponent nanomaterials responsive to both low and high energy X-rays. This research will have a tremendous educational impact on the Mechanical and Nuclear Engineering program at Virginia Commonwealth University (VCU). The new knowledge in materials and radiation chemistry, advanced nanomaterials synthesis, and manufacturing will be disseminated in the undergraduate and graduate courses. The research proposed here will also be a significant boon for the nuclear science at James Madison University (JMU) and will include undergraduates in the interdisciplinary-research projects. The diverse experience the students will gain while working on this interdisciplinary project will create a multitude of opportunities for those seeking careers in nuclear engineering, applied photon science, nanoscience, accelerator physics, or medical physics, as well as for those directly entering the workforce in nuclear industry or government.Technical SummaryThis research project will advance both the fundamental understanding of the underlying mechanism of radiation dose enhancement and the radioluminescence response upon the nanocomposites interacting with high-energy photons. The work will build upon the theory of radiation interaction with matter and expand on the surface and interfacial effects in aqueous media that lead to the radiation enhancement phenomenon. This project focuses on three key areas: 1) Expand on the controlled synthesis of multicomponent nanomaterials to explore their mechanisms of interaction with ionizing radiation; 2) Investigate their radioluminescence and radiation enhancing properties; 3) Implement computational models based on Monte Carlo simulations to assess the contribution of the physical enhancement to the radiosensitization properties of the nanomaterials based on their chemical compositions and morphologies. The experimental work will involve chemical, electrochemical, and spectroscopic techniques to quantify reactive species involved in the radiation enhancement and the materials' optical properties. Computational work will be carried out using GEANT4 particle transport code to model the interaction of the X-rays with the studied nanostructures. Ultimately, this research will establish correlations between the material structure and properties in the solid-state, specifically considering the effects of the X-ray parameters such as the energy spectrum of the X-ray beam and the rate at which the energy is delivered to the system have on the behavior of the materials systems. Overall, the proposed experimental and computational tools will lead to an understanding of the structure-property relationships of the nanomaterials and will advance the synthesis, evaluation, and simulation of radiation enhancing and radioluminescent nanomaterials to enable their implementation in various fields. Overall, both the undergraduate and graduate students involved in this work will have the opportunity to get hands-on experience in an accelerator-based environment at the JMU's Madison Accelerator Laboratory while participating in cutting-edge interdisciplinary research both at VCU and JMU.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.