NSF-DFG: Nonequilibrium thermal processing of nanoparticles: Laser melting and fragmentation in liquid

NSF-DFG：纳米粒子的非平衡热处理：液体中的激光熔化和破碎

• 批准号: 521278458
• 负责人: Professor Dr.-Ing. Stephan Barcikowski
• 金额: --
• 依托单位: Lehrstuhl für Technische Chemie I
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/521278458?language=en
• 关键词: NSF; DFG; Nonequilibrium; thermal; processing

Laser fragmentation in liquids (LFL) and laser melting in liquids (LML) are nonequilibrium thermal processing techniques to fabricate highly pure nanoparticles (NPs) for catalysis, optics, and biomedicine. However, the underlying NP formation mechanisms are still poorly understood. The twofold objective of the proposed NSF-DFG-funded joint computational and experimental study is (1) to deepen the understanding of the fundamental mechanisms of the laser-induced modification of NPs in liquid and (2) to facilitate the advancement of the NP synthesis techniques guided by an understanding of the processes that control the sizes, shapes, and structures of NPs produced by LFL and LML. Pt, Au, and PtAu alloy NPs are chosen as model materials and computational prediction and experimental verification of the particle´s elemental composition and defect density are used as major readouts. An advanced computational model for the realistic simulation of the NP fragmentation dynamics during LFL and LML will be 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 NPs. Transient optical properties will be calculated for NPs 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 NP processing also in a double-pulse (pump-pump) irradiation strategy.

液体激光碎裂（LFL）和液体激光熔融（LML）是制备用于催化、光学和生物医学的高纯度纳米粒子（NPs）的非平衡热加工技术。然而，潜在的NP形成机制仍然知之甚少。这项由nsf - dfg资助的联合计算和实验研究的双重目标是：(1)加深对液体中激光诱导修饰NPs的基本机制的理解；(2)通过理解LFL和LML产生的NPs的大小、形状和结构的控制过程，促进NPs合成技术的进步。选择Pt、Au和PtAu合金纳米粒子作为模型材料，并将粒子元素组成和缺陷密度的计算预测和实验验证作为主要读数。在LFL和LML过程中，将开发一个先进的计算模型来真实模拟NP碎片动力学，并在实验中使用连续流平面射流激光处理装置进行验证，以确保精确控制分散NP的脉冲数和激光通量暴露。将计算经过激光诱导熔化和解体的NP的瞬态光学性质，以促进与时间分辨实验光学探测（泵浦探测）结果的联系，并揭示在双脉冲（泵浦-泵浦）照射策略中节能NP处理的最佳条件。