Mechanisms of Nanoparticle Generation by Laser Ablation of Thin Films in Liquids

这笔拨款将支持一个整合良好的协作实验？液体环境中短脉冲激光烧蚀金属薄膜和多层膜中纳米粒子产生机理的计算研究。控制纳米粒子产生的关键过程将通过大规模的原子模拟和实验来研究，这些实验针对嵌入在水、丙酮和甲苯等常见液体中的薄膜目标，并在短(飞秒到纳秒)激光脉冲照射下进行。在模拟中揭示的关于激光烧蚀和纳米颗粒形成的高度非平衡过程的详细微观信息将被用于指导确保对纳米颗粒的尺寸分布、结构和组成进行精细控制的条件的实验探索。沉积激光能量在被辐照薄膜中的空间约束作用以及被抛射的烧蚀羽流与液体环境的相互作用是有待计算和实验研究的关键问题之一。本研究结果将为优化实验装置的设计提供指导，以产生满足特定应用需要的结构和组成的纳米粒子。这将使个人研究人员能够为他们的研究项目生产纳米颗粒，而这些纳米颗粒并不容易在商业上获得，或者如果商业上可以获得的话，成本很高。具有窄尺寸分布和无污染的纳米粒子的产生具有很好的潜在影响，包括生物医学研究、先进材料的纳米工程、光电子学和表面催化。以本科生为主的罗格斯-卡姆登大学和以研究为导向的弗吉尼亚大学之间的密切互动，将为不同的本科生和研究生群体提供独特的教育机会。

This grant will support a well-integrated collaborative experimental ? computational study of the mechanisms of nanoparticle generation in short pulse laser ablation of thin metal films and multi-layers in a liquid environment. The key processes that control the generation of nanoparticles will be investigated in large-scale atomistic simulations and experiments performed for thin film targets embedded in common liquids, such as water, acetone, and toluene, and irradiated by short (femtosecond to nanosecond) laser pulses. The detailed microscopic information on highly non-equilibrium processes of laser ablation and nanoparticle formation, revealed in the simulations, will be used to guide the experimental exploration of conditions that ensure fine control over the nanoparticle size distribution, structure and composition. The role of the spatial confinement of the deposited laser energy within the irradiated films and the interaction of the ejected ablation plume with liquid environment are among the key questions to be investigated computationally and in experiments.The results of this study will provide guidance for the design of experimental setups optimized for the generation of nanoparticles with structure and composition meeting the needs of particular applications. This will enable individual researchers to produce nanoparticles for their research projects that are not readily available commercially, or if they are, at a great cost. The generation of nanoparticles with a narrow size distribution and free of contaminants has a good potential to impact many applications, including biomedical research, nanoengineering of advanced materials, optoelectronics, and surface catalysis. The close interaction between Rutgers-Camden, a predominantly undergraduate institution, and the University of Virginia, a research-oriented institution, will provide unique educational opportunities to a diverse group of undergraduate and graduate students.