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合作实验。液体环境下短脉冲激光烧蚀金属薄膜和多层膜纳米颗粒生成机制的计算研究。控制纳米颗粒生成的关键过程将在大规模原子模拟和实验中进行研究，这些实验是对嵌入在普通液体（如水、丙酮和甲苯）中的薄膜目标进行的，并由短（飞秒到纳秒）激光脉冲照射。模拟中揭示的激光烧蚀和纳米颗粒形成高度非平衡过程的详细微观信息，将用于指导实验探索确保对纳米颗粒尺寸分布、结构和组成进行精细控制的条件。沉积的激光能量在辐照膜内的空间约束作用以及喷射的烧蚀羽流与液体环境的相互作用是需要在计算和实验中研究的关键问题。本研究的结果将为实验装置的设计提供指导，以优化纳米颗粒的结构和组成，满足特定应用的需要。这将使个别研究人员能够为他们的研究项目生产纳米颗粒，这些纳米颗粒不容易在商业上获得，或者即使有，也要付出很大的代价。纳米颗粒的生成具有狭窄的尺寸分布和无污染物，具有良好的潜力影响许多应用，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，将为不同群体的本科生和研究生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.