NSF-DFG: Nonequilibrium Thermal Processing of Nanoparticles via Laser Melting and Fragmentation in Liquid

NSF-DFG：通过激光熔化和液体破碎对纳米颗粒进行非平衡热处理

• 批准号: 2302577
• 负责人: Leonid Zhigilei
• 金额: $ 43.25万
• 依托单位: University of Virginia Main Campus
• 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 2026-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2302577&HistoricalAwards=false
• 关键词: NSF; DFG; Nonequilibrium; Thermal; Processing

The widespread and rapidly expanding use of nanoparticles in the manufacturing of advanced nanomaterials for applications in catalysis and biomedicine calls for the development of nanoparticle manufacturing techniques capable of meeting the sharp rise in global demand. Laser processing of colloidal solutions of nanoparticles is a unique green chemistry technique, working at room temperature and ambient pressure without the need for any chemical additives or reactants, saving resources and minimizing waste. To fully unleash the potential of this scalable nanomanufacturing technique, this award supports fundamental research to reveal, through tightly integrated computer modeling and experiments, the fundamental mechanisms of the laser-induced modification of nanoparticles in a liquid environment. These insights into mechanisms of nanoparticle formation foster the advancement of manufacturing techniques for environment-friendly and energy-efficient generation of nanoparticles with sizes and structural characteristics that meet the high demand of future developments in catalysis and biomedicine. The multidisciplinary nature of the research and the international collaboration with the University of Duisburg Essen, Germany facilitate the professional preparation of a new generation of researchers ready for work at the forefront of the rapidly expanding fields of laser-based advanced manufacturing and scientific computing. The impact of the project is augmented by bringing an established International Conference on Advanced Nanoparticle Generation and Excitation by Lasers in Liquids to the US for the first time and broadening participation of US students in the Venice International School on Lasers in Materials Science.Laser fragmentation in liquids and laser melting in liquids are two nonequilibrium thermal processing techniques to fabricate chemically clean nanoparticles for catalysis and biomedicine. However, the underlying nanoparticle formation mechanisms are poorly understood. This project tackles the challenge of probing the rapid highly nonequilibrium processes triggered by short pulse laser irradiation by combining multiscale and multiphysics modeling, time-resolved optical probing, and ex situ characterization of nanoparticle phase composition and defect density. An advanced computational model for investigation of the nanoparticle fragmentation and melting dynamics is developed and verified in experiments using a continuous-flow flat jet laser processing setup that ensures precise control over the pulse number and laser fluence exposure of dispersed nanoparticles. Transient optical properties are calculated for nanoparticles undergoing laser-induced melting and disintegration to facilitate the connections to the results of time-resolved experimental optical probing (pump-probe) and to reveal optimum conditions for the energy-efficient nanoparticle processing in a novel double-pulse irradiation strategy. These optimum conditions are key for better nanoparticle size, shape, and structure control, as well as for further upscaling.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.

纳米粒子在催化和生物医学应用的先进纳米材料的制造中的广泛和快速扩展的使用要求开发能够满足全球需求急剧增长的纳米粒子制造技术。纳米粒子胶体溶液的激光加工是一种独特的绿色化学技术，在室温和环境压力下工作，不需要任何化学添加剂或反应物，节省资源并最大限度地减少浪费。为了充分释放这种可扩展的纳米制造技术的潜力，该奖项支持基础研究，通过紧密集成的计算机建模和实验揭示液体环境中纳米颗粒激光诱导改性的基本机制。这些对纳米颗粒形成机制的见解促进了制造技术的进步，以环境友好和节能的方式生成纳米颗粒，其尺寸和结构特征可以满足催化和生物医学未来发展的高需求。该研究的多学科性质以及与德国杜伊斯堡埃森大学的国际合作促进了新一代研究人员的专业准备，为在快速扩展的基于激光的先进制造和科学计算领域的前沿工作做好准备。通过首次在美国举办关于液体中激光产生和激发先进纳米颗粒的国际会议，以及扩大威尼斯材料科学激光国际学校的美国学生的参与，增强了该项目的影响力。液体和液体中的激光熔化是两种非平衡热处理技术，用于制造用于催化和生物医学的化学清洁纳米颗粒。然而，人们对潜在的纳米颗粒形成机制知之甚少。该项目通过结合多尺度和多物理场建模、时间分辨光学探测以及纳米粒子相组成和缺陷密度的非原位表征，解决了探测由短脉冲激光照射引发的快速高度非平衡过程的挑战。使用连续流平面射流激光加工装置开发并在实验中验证了用于研究纳米粒子破碎和熔化动力学的先进计算模型，该模型确保了对分散纳米粒子的脉冲数和激光注量暴露的精确控制。计算经历激光诱导熔化和分解的纳米颗粒的瞬态光学特性，以促进与时间分辨实验光学探测（泵浦探针）结果的连接，并揭示新型双通道中节能纳米颗粒加工的最佳条件。脉冲照射策略。这些最佳条件是更好地控制纳米颗粒尺寸、形状和结构以及进一步升级的关键。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。