Mechanistische Untersuchung der Nanopartikelbildung während des Laserstrahlabtragens in Flüssigkeit mit neuartigen Röntgenmethoden

• Antragsteller: Professor Dr.-Ing. Stephan Barcikowski; Privatdozent Dr. Anton Plech
• Fachliche Zuordnung: Physikalische Chemie von Molekülen, Flüssigkeiten und Grenzflächen, Biophysikalische Chemie ; Herstellung und Eigenschaften von Funktionsmaterialien
• Förderung: Förderung von 2014 bis 2020
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 262558940

• Erstellungsjahr: 2021

Zusammenfassung der Projektergebnisse

The goal of the present project has been to resolve the dynamics of pulsed laser ablation in liquids (PLAL) by hierarchical in-situ methods and to correlate the nanoparticle genesis during this process with the macroscopic phenomenology. This requires the development and application of methods, which are sensitive to a millimeter down to a nanometer length scale including high time resolution on the microsecond scale. This has been achieved by correlating spatiotemporally resolved smallangle X-ray scattering (SAXS), UV-visual spectroscopic methods, visual stroboscopy (VISIMG) with fast X-ray imaging (XI) with contrast variation (XHI). In the first part of the project, we have developed contrast variation (as Hartmann imaging) in order to be sensitive to the macroscale (absorption XR and phase-contrast XPC) and nanoscale (dark-field contrast). At the same time, the correlation of bubble dynamics and particle formation in terms of particle size distribution and yield has been explored. In the second part (project prolongation) specifically, the origins of bimodal size distribution have been investigated as well as speciation in post-ablation particle oxidation. XHI has been fully developed to use X-ray lens arrays as an X-ray variant of Shack-Hartmann sensing. Several milestone results have been achieved that drew considerable attention in the scientific community: Particle size distribution, in particular, the usually observed bi- or multimodal distribution have inherent origins in the early stages of the process itself: Large (liquid) particles may be ejected in short-pulse (picosecond) PLAL through the mechanism of liquid film detachment and jet formation, while also a second-stage agglomeration of particles trapped inside the bubble will cause size coarsening. Quenching of particle sizes therefore can already be active in the bubble, if electrolytes are added and prevent agglomeration during bubble collapse. The coupling of energy into the system and thus process efficiency can be monitored by the bubble sizes, both in terms of laser fluence and coupling-related incubation. Oxidation, in particular in the zinc system is characterized by the initial production of metallic zinc particles, which undergo gradual oxidation in water to form ZnO. Time-resolved X-ray absorption spectroscopy was for the first time employed for the study. In long-pulse (nanosecond) ablation a large fraction of the ablated species inside the bubble consists of isolated, active zinc species, which grow into particles within the duration of the first bubble. Method development aiding the resolution of dynamics and detection of formed nanoparticles includes a thorough discussion of size definition through alternative (ex-situ) methods, development of time-resolved X-ray small-angle scattering (SAXS), X-ray imaging (XI), and X-ray spectroscopy (XAS). In particular, XI and SAXS could be merged into a contrast variable imaging technique using a Shack-Hartmann setup with arrays of X-ray microbeams. This technique stimulated further developments at KIT.

Projektbezogene Publikationen (Auswahl)

• A hierarchical view on material formation during pulsed-laser synthesis of nanoparticles in liquid, Sci. Rep., 5 (2015) 16313
  S. Ibrahimkutty, P. Wagener, T. dos Santos Rolo, D. Karpov, A. Menzel, T. Baumbach, S. Barcikowski, A. Plech
  
• Pulsed laser ablation in liquids: Interaction of the bubble with particle formation, J. Coll. Interf. Sci., 489 (2017) 106-113
  S. Reich, P. Schönfeld, P. Wagener, A. Letzel, B. Gökce, A. Menzel, T. dos Santos Rolo, S. Barcikowski. A. Plech
  
• Size quenching during laser synthesis of colloids happens already in the vapor phase of the cavitation bubble, J. Phys. Chem. C, 121 (2017) 5356-5365
  A. Letzel, B. Gökce, P. Wagener, S. Ibrahimkutty, A. Menzel, A. Plech, S. Barcikowski
  
• A Shack-Hartmann sensor for single-shot multi-contrast direct- and reciprocal space in-situ imaging with hard X-rays, Appl. Sci. (Basel) 8 (2018) 737
  T. dos Santos Rolo, S. Reich, D. Karpov, S. Gasilov, T. Baumbach, D. Kunka, A. Plech
  
• Primary particle diameter differentiation and bimodality identification by five analytical methods using gold nanoparticle size distributions synthesized by pulsed laser ablation in liquids, Appl. Surf. Sci. 435 (2018) 743
  A. Letzel, B. Gökce, A. Menzel, A. Plech and S. Barcikowski
  
• Scalable, large area compound array refractive lens for hard X-rays, Appl. Phys. Lett. 112 (2018) 151903
  S. Reich, T. dos Santos Rolo, A. Letzel, T. Baumbach, A. Plech
  
• Early appearance of crystalline nanoparticles in pulsed laser ablation in liquids dynamics, Nanoscale 11 (2019) 6962 - 6969
  S. Reich, A. Letzel, A. Menzel, N. Kretzschmar, B. Gökce, S. Barcikowski, A. Plech
  
• Materials synthesis in a bubble, MRS Bulletin 44 (2019) 382-391
  Barcikowski, A. Plech, K. S. Suslick, A. Vogel
  
• Time and Mechanism of Nanoparticle Functionalization by Macromolecular Ligands during Pulsed Laser Ablation in Liquids, Langmuir 35 (2019) 3038-3047
  A. Letzel, S. Reich, T. dos Santos Rolo, A. Kanitz, J. Hoppius, A. Rack, M. Olbinado, A. Ostendorf, B. Gökce, A. Plech, S. Barcikowski
  
• In situ speciation and spatial mapping of Zn products during pulsed laser ablation in liquids (PLAL), Nanoscale 12 (2020) 14011-14020
  S. Reich, J. Göttlicher, A. Ziefuss, R. Streubel, G. Smolentsev, A. Letzel, S. Barcikowski, A. Menzel, O. Mathon, S. Pascarelli, T. Baumbach, M. Zuber, A. Plech