Pulsed Laser System for Nanoparticle Production and Processing

液体中的脉冲激光烧蚀和液体中的脉冲激光破碎方法使胶体纳米粒子的生产和加工能够在高纯度条件下进行。由于纳米粒子固有的高比表面积，表面纯度对于区分表面功能和表面吸附效应非常重要。高表面纯度是脉冲激光系统制备纳米粒子的一大优点，这也是近年来这些基于激光的方法日益成为研究热点的原因。而脉冲激光在液体中的烧蚀已被广泛地应用于各种材料。脉冲激光破碎的研究主要是在表面等离子体(即可见光波长的激光脉冲)的共振激发下对金纳米颗粒等模型金属材料进行的。由于现有高功率激光器对可见光/红外激光脉冲的低吸收，用于添加剂制造或摩擦学的氧化物纳米颗粒的进一步研究在吞吐量和颗粒尺寸方面受到严重限制。相比之下，紫外激光脉冲的吸收截面要大得多(特别是对半导体、氧化物和大多数金属纳米颗粒)。因此，通过使用紫外光激光，激光烧蚀和碎裂的研究变得更加高效和多样化成为可能。利用我们组中现有的红外激光器，只有在数量不足的情况下，才可能发生氧化物(例如Y2O3、ZrO2)、高熔点硬质材料(例如ZrB2、TiB2、TiC)或高熵合金(例如康托合金)的破碎。由于应用前景和功能测试的数量要求(例如，在添加剂制造中)，生产能力的显著增加具有相当大的研究潜力。这些激光生产和加工的材料被应用于申请者的几个研究项目，包括协调计划。因此，拟议的高功率紫外光激光系统在新任命的材料科学和添加剂制造主席的研究光谱中占据了关键地位。同时，它将加强伍珀塔尔大学的核心“材料.灵感.系统”的形象。这一主要仪器的规格是根据与基础和应用研究项目相关的材料和必要的生产能力确定的。这些项目需要高纯度的胶体纳米颗粒，部分规模为100克。因此，主席正在进行的一系列项目将受益于新的文书。此外，激光粉床融合领域的进一步项目方法(每批几公斤纳米添加微粉)将变得可行。利用所提议的设备可以实施的连续运行的高性能紫外激光分散体生产和加工技术将成为国际上的一个显著特点。

The methods of pulsed laser ablation in liquids and pulsed laser fragmentation in liquids enable the production and processing of colloidal nanoparticles under high-purity conditions. Due to the inherent high specific surface area of nanoparticles, surface purity is of great importance for the discrimination of surface functionality from surface adsorbate effects. The high surface purity is one of the great strengths of nanoparticle production by pulsed laser systems, which is why these laser-based methods have increasingly become the focus of research in recent years. While pulsed laser ablation in liquids has been applied to a broad range of materials. Investigation of pulsed laser fragmentation has been carried out mainly on model metal materials such as gold nanoparticles under resonant excitation of the surface plasmons (i.e., laser pulses in the visible wavelength). Further studies on oxide nanoparticles employed for additive manufacturing or tribology are severely limited in throughput and particle size due to the low absorption of VIS/IR laser pulses employed in existing high-power lasers. UV- laser pulses, in contrast, show a much larger absorption cross-section (especially for semiconductors, oxides, and most metal nanoparticles). Consequently, by using UV-lasers, a much more efficient and material-variant research of laser ablation and fragmentation is possible. With the existing IR-lasers in our group, fragmentation of, e.g., oxides (e.g., Y2O3, ZrO2), high melting hard materials (e.g., ZrB2, TiB2, TiC) or high entropy alloys (e.g., Cantor-Alloy) is only possible in insufficient quantity frameworks. The significant increase in throughput has considerable research potential due to the application perspective and the quantity requirement for functional testing (e.g., in additive manufacturing). The laser-produced and processed materials are applied in several research projects of the applicant, including coordinated programs. The proposed high-power UV laser system thus occupies a key position that exerts a leverage effect on the research spectrum at the newly appointed Chair of Materials Science and Additive Manufacturing. Meanwhile, it will strengthen the profile core “Materials.Inspire.Systems” of the University of Wuppertal. The specifications of this major instrumentation are defined based on materials and necessary throughputs relevant to basic and applied research projects. These require high-purity colloidal nanoparticles partly on a scale of 100 g. Accordingly, a whole series of ongoing projects at the Chair will benefit from the new instrument. In addition, further project approaches in the field of laser powder bed fusion (several kg of nanoadditivated micropowder per batch) will become feasible. The continuously operated high-performance UV laser production and processing technology for dispersions that can be implemented with the proposed equipment will represent a distinguishing feature internationally.